Reciprocating 2-stroke cycle internal combustion engine

• US 5,261,359 A
• Filed: 08/02/1991
• Issued: 11/16/1993
• Est. Priority Date: 09/13/1990
• Status: Expired due to Fees

• Current Assignee: Francis R. Hull
• Original Assignee: Francis R. Hull
• Inventors: Hull, Francis R.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US07/739,527
• Time in Patent Office: 837 Days
• Field of Search: 123/59 AB, 123/188.5, 123/65 R, 123/65 V, 123/65 P, 123/73 A, 123/81 R, 123/65 BA, 123/547, 123/188.4
• US Class Current: 123/65.00V
• CPC Class Codes: F01L 15/02 with valves other than cylindrical, sleeve, or part-annularly-shaped, e.g. flat D-valves
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02B 25/02 using unidirectional scavenging
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02M 31/087 Heat-exchange arrangements between the air intake and exhaust gas passages, e.g. by means of contact between the passages
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A superchargeable multi-cylinder 2-stroke cycle internal combustion engine employs opposite reciprocating mult-port slide valves in guideways on opposite sides of the engine block, to open and close cylinder air supply and combustion gas discharge conduits in several variations. Use of opposite multi-port slide valves driven from the engine crankshaft simplifies engine design, and improves scavenging of combustion gases from piston chambers of either spark-ignition or diesel engines. A preferred variation channels air supply and combustion gas discharge flows through dual passageways of opposite air preheating manifolds, to increase engine fuel efficiency, Further development of the preferred variation can result in production of simplified, compact, supercharged 2-stroke spark-ignition and diesel engines of improved design.

Claims

1. A reciprocating 2-stroke cycle multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber having a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft having a plurality of crankpins disposed in a crankcase portion of said engine block on the low-pressure side of each said reciprocating piston, a plurality of connecting rods having members which are each pivotally connected at one end onto a said crank pin of said crankshaft and pivotally connected at its other end onto the corresponding said wrist pin of each individual said piston, a cylinder head closing the said plurality of piston chambers on the high-pressure portion of said engine block, a cover closing said crankcase portion of said engine block, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, comprising in combination:

air inlet means disposed in said crankcase portion of said engine block, to admit pressurized combustion air thereinto;

a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said crankcase;

each member of said plurality of piston chambers having a pair of opposite inlet ports disposed therein to admit pressurized combustion air thereinto, and a pair of opposite outlet ports disposed therein to discharge spent combustion gases therefrom;

a plurality of air supply conduits having members communicating between said pressurized crankcase and corresponding said opposite inlet ports of each said piston chamber, for intermittent passage of pressurized combustion air thereinto;

a plurality of combustion gas discharge conduits having members communicating between exterior exhaust conduit means and corresponding said opposite outlet ports of each said piston chamber, for intermittent discharge of spent combustion gases therefrom;

a plurality of multi-port slide valve means having opposite members which are linked together and slideably disposed on opposite sides of each said piston chamber in guideway means of said engine block, and disposed therein to reciprocate together;

transmission means communicating between said crankshaft and means linking the slideable motion of members of said plurality of multi-port slide valve means and disposed to continuously convert rotary motion to reciprocating motion, so that members of said plurality of opposite multi-port slide valve means reciprocate together and complete each reciprocating cycle in conjunction with completion of the designed rotation of said crankshaft;

members of said plurality of reciprocating oppositely-disposed multi-port slide valve means being disposed across corresponding members of said plurality of air supply and combustion gas discharge conduits which communicate with corresponding said opposite inlet ports and opposite outlet ports of each member of said plurality of piston chambers, to intermittently open and close corresponding said members of said plurality of air supply and combustion gas discharge conduits during reciprocation of said plurality of opposite multi-port slide valve means; and

members of said plurality of reciprocating oppositely-disposed multi-port slide valve means each having companion sets of inlet and outlet ports for passage of fluids therethrough and disposed therein so that corresponding said air supply conduits and corresponding said combustion gas discharge conduits servicing each said piston chamber are intermittently opened in sequence during reciprocation of said plurality of opposite multi-port slide valve means when each corresponding said piston is near its bottom dead-center cyclic position, to sequentially admit a fresh charge of pressurized combustion air into each said piston chamber from its said opposite inlet ports that displaces and impels the discharge of spent combustion gases through its said opposite outlet ports;

whereby each member of said plurality of piston chambers is sequentially purged of spent combustion gases by an admitted charge of pressurized combustion air from said crankcase while its corresponding said piston is near its bottom dead-center cyclic position, as corresponding said members of its plurality of air supply and combustion gas discharge conduits are intermittently opened through corresponding said inlet and outlet ports of members of said plurality of reciprocating opposite multi-port slide valve means, and corresponding members of said plurality of air supply and combustion gas discharge conduits servicing each said piston chamber are intermittently closed in sequence by members of said plurality of reciprocating opposite multi-port slide valve means during the compression stroke of each corresponding said piston.

2. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 1 wherein a plurality of liquid fuel injectors is disposed in said cylinder head., each member of said plurality of liquid fuel injectors having its outlet exposed into a corresponding said member of said plurality of piston chambers, a fluid pump disposed to supply high-pressure liquid fuel through communicating conduit means into an inlet of each said fuel injector, valve means disposed in a fuel supply conduit branch serving each said fuel injector, and valve operating means disposed to intermittently open said valve means serving each said fuel injector and admit high-pressure liquid fuel into its corresponding said piston chamber, when its corresponding said piston approaching its top dead-center cyclic position.

3. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 1 wherein a plurality of electrical spark plugs is disposed in said cylinder head, each member of said plurality of electrical spark plugs having its electrodes exposed into a corresponding member of said plurality of piston chambers, a source of high-voltage electrical current, electrical conductor means communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, and electrical switch means disposed in a conductor branch communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, to intermittently energize electrodes of each said electrical spark plug and ignite the compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position.

4. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 1 wherein each said piston member closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its corresponding said piston chamber, and the heat of compression from work done on a combustion air charge by each said piston member elevates combustion air temperature above the fuel ignition temperature to spontaneously ignite a combustible fuel supplied into its corresponding said piston chamber,

5. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 1 wherein members of a pair of opposite exterior exhaust manifolds are individually disposed to communicate with corresponding members of said plurality of combustion gas discharge conduits which serve said outlet ports of said plurality of piston chambers on each side of said engine block, and said pair of opposite exterior exhaust manifolds collect the combined exhaust of spent combustion gases discharged from outlet ports of said plurality of piston chambers.

6. A reciprocating 2-stroke cycle multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber having a reciprocating piston disposed therewithin to compress or expand gaseous fluids a rotary crankshaft having a plurality of crank pins disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a plurality of wrist pins having members individually disposed onto the low-pressure side of each said reciprocating piston, a plurality of connecting rods having members which are each pivotally connected at one end onto a said crank pin of said crankshaft and pivotally connected at its other end onto the corresponding said wrist pin of its individual piston, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head closing said plurality of piston chambers on the high-pressure portion of said engine block, a cover closing said crankcase portion of said engine block, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, comprising in combination:

air inlet means disposed in said crankcase portion of said engine block, for admission of combustion air thereinto;

each member of said plurality of piston chambers having a plurality of cylinder ports disposed in the sidewall thereof for intermittent admission of combustion air thereinto, and a pair of second cylinder ports oppositely disposed in the sidewall thereof adjacent said cylinder head for intermittent discharge of spent combustion gases therefrom;

the first said plurality of cylinder ports being disposed in the sidewall of each said piston chamber so as to be substantially uncovered by the sidewall of its corresponding said piston near the bottom dead-center position of its power strokes and substantially closed by the sidewall of its corresponding said piston during its compression stroke;

a plurality of air supply conduits communicating between said crankcase and members of said plurality of first said cylinder ports of each said piston chamber;

a plurality of combustion gas discharge conduits communicating between said pair of oppositely-disposed second cylinder ports of each said piston chamber and exterior exhaust conduit means;

a pair of multi-port slide valve means having opposite members which are linked together and slideably disposed on opposite

sides of each said piston chamber in guideway means of said engine block, and disposed therein to reciprocate together;

transmission means communicating between said crankshaft and means linking members of said pair of multi-port slide valve means and disposed to continuously convert rotary motion to reciprocating motion, so that members of said pair of oppositely-disposed multi-port slide valve means reciprocate together and continuously complete each reciprocating cycle in conjunction with completion of the designed rotation of said crankshaft;

members of said pair of reciprocating multi-port slide valve means being disposed across corresponding members of said plurality of combustion gas discharge conduits which communicate with corresponding members of said pair of oppositely-disposed second cylinder ports of each member of said plurality of piston chambers, to intermittently open and close corresponding members of said plurality of combustion gas discharge conduits serving each said piston chamber during reciprocation of said pair of oppositely-disposed multi-port slide valve means; and

members of said pair of reciprocating oppositely-disposed multiport slide valve means having companion sets of outlet ports for passage of fluids therethrough and disposed therein so that corresponding said combustion gas discharge conduits servicing each said piston chamber are intermittently opened in sequence during reciprocation of said pair of oppositely-disposed multi-port slide valve means when each corresponding said piston is near its bottom dead-center cyclic position, and spent combustion gases are sequentially discharged from each said piston chamber;

whereby each member of said plurality of piston chambers is sequentially purged of spent combustion gases by a charge of fresh combustion air admitted thereinto from said crankcase while its corresponding said piston is near its bottom dead-center cyclic position, as corresponding members of said plurality of combustion gas discharge conduits are opened through corresponding said outlet ports of said pair of reciprocating multi-port slide valve means, and corresponding said members of said plurality of combustion gas discharge conduits servicing each said piston chamber are intermittently closed in sequence by members of said pair of reciprocating multi-port slide valve means during the compression stroke of each said piston.

7. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 6 wherein a fluid pump is disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said crankcase.

8. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 6 wherein a plurality of liquid fuel injectors is disposed in said cylinder head, each member of said plurality of liquid fuel injectors having its outlet exposed into a corresponding member of said plurality of piston chambers, a fluid pump disposed to supply high-pressure liquid fuel through communicating conduit means into an inlet of each said fuel injector, valve means disposed in a fuel supply conduit branch serving each said fuel injector, and valve operating means disposed to intermittently open each said valve means serving each said fuel injector and discharge high-pressure liquid fuel into its corresponding said piston chamber, as its corresponding said piston approaches its top dead-center cyclic position.

9. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 6 wherein a plurality of electrical spark plugs is disposed in said cylinder head, each member of said plurality of electrical spark plugs having its electrode s exposed into a corresponding member of said plurality of piston chambers, a source of high-voltage electrical current, electrical conductor means communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, and electrical switch means disposed in a conductor branch communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, to intermittently energize electrodes of each said electrical spark plug and ignite the compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position.

10. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 6 wherein each said piston member closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its corresponding said piston chamber, and the heat of compression from work done on a combustion air charge by each said piston member elevates combustion air temperature above the fuel ignition temperature to spontaneously ignite a combustible fuel supplied into its corresponding said piston chamber.

11. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 6 wherein members of a pair of opposite exterior exhaust manifolds communicate with corresponding members of said plurality of combustion gas discharge conduits serving members of said pair of oppositely-disposed second cylinder ports on each side of said engine block, and said pair of opposite exterior exhaust manifolds collect the combined discharge of spent combustion gases from said second cylinder ports of said plurality of piston chambers.

12. A method for operating a reciprocating 2-stroke cycle internal combustion engine having an engine block housing a piston chamber with a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft with crank pin disposed in a crankcase portion of said engine block on the low-pressure side of said piston, a wrist pin disposed onto the low-pressure side of said piston, a connecting rod having one end pivotally connected onto said wrist pin with its other end pivotally connected onto said crank pin and disposed to transmit a variable torque to said crankshaft during reciprocation of said piston, a cylinder head of said engine block closing the high-pressure portion of said piston chamber, a cover closing said crankcase portion of said engine block, air inlet means disposed in said crankcase portion of said engine block, check valve means disposed in said air inlet means of said crankcase, a plurality of air supply conduits communicating between said crankcase and a plurality of cylinder ports disposed in an extended portion of said piston chamber which are opened and closed by the sidewall of said piston during its reciprocation, a plurality of combustion gas discharge conduits communicating between a pair of opposite second cylinder ports of said piston chamber disposed adjacent said cylinder head and an atmospheric exhaust outlet, a linked pair of reciprocating ported slide valve members each having an outlet port for flow of fluids therethrough and slideably disposed opposite each other in guideway means of said engine block across said plurality of combustion gas discharge conduits to open and close said plurality of combustion gas discharge conduits during reciprocation of said linked pair of ported slide valve members, means for actuating the reciprocation of said linked pair of ported slide valve members, means for intermittently supplying a combustible fuel into said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within said piston chamber when said piston is near its top dead-center cyclic position, said method comprising the combinative steps of:

inducing the flow of atmospheric combustion air into said crankcase by the vacuum produced by said reciprocating piston during its compression stroke;

pressurizing combustion air within said crankcase by said reciprocating piston during its extending power stroke;

flowing a charge of combustion air from said crankcase through said plurality of air supply conduits and into said piston chamber, when said plurality of first cylinder ports are uncovered by said piston near its bottom dead&

-center cyclic position;

transforming rotary motion of said crankshaft to reciprocating motion of said linked pair of ported slide valve members in transmission means which communicate between said crankshaft and said linked pair of ported slide valve members;

synchronizing the reciprocation of said linked pair of ported slide valve members with rotation of said crankshaft, so that said linked pair of ported slide valve members continuously completes each reciprocating cycle in conjunction with completion of the designed rotation of said crankshaft;

discharging spent combustion gases from said piston chamber through said pair of opposite second cylinder ports and said plurality of combustion gas discharge conduits by way of said outlet ports of said linked pair of reciprocating ported slide valve members, when said piston is near its bottom dead-center cyclic position;

impelling the discharge of spent combustion gases from said piston chamber while said piston is near its bottom dead-center cyclic position, by admitting a charge of combustion air thereinto which displaces and expels spent combustion gases therefrom;

stopping the discharge of gaseous fluids from said piston chamber during the compression stroke of said piston, when said linked pair of ported slide valve members closes said plurality of combustion gas discharge conduits;

injecting a dispersed liquid fuel into said piston chamber, as said piston approaches its top dead-center cyclic position, and

igniting the compressed air-fuel mixture within said piston chamber by an electric spark, as said piston approaches its top dead-center cyclic position.

13. The method of claim 12 wherein the said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of said piston chamber during its compression stroke, said engine having no spark-ignition means, with the additional steps of:

compressing the combustion air charge supplied into said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into the heated air charge within said piston chamber, as said piston approaches its top dead-center cyclic position; and

spontaneously igniting the compressed air-fuel mixture within said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

14. A method for operating a reciprocating 2-stroke cycle internal combustion engine having an engine block housing a piston chamber with a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crank shaft with crank pin disposed in a crankcase portion of said engine block on the low-pressure side of said piston, a wrist pin disposed onto the low-pressure side of said piston, a connecting rod having one end pivotally connected onto said wrist pin with its other end pivotally connected onto said crank pin and disposed to transmit a variable torque to said crankshaft during reciprocation of said piston, a cylinder head of said engine block closing the high-pressure portion of said piston chamber, a cover closing said crankcase portion of said engine block, air inlet means disposed in said crankcase portion of said engine block, a plurality of air supply conduits communicating between a pair of opposite cylinder ports disposed in an extended portion of said piston chamber, a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said crankcase, a plurality of combustion gas discharge conduits communicating between a pair of opposite second cylinder ports of said piston chamber disposed adjacent said cylinder head and an atmospheric exhaust outlet, a linked pair of reciprocating multi-port slide valve members each having inlet and outlet ports for flow of fluids therethrough and slideably disposed opposite each other in guideway means of said engine block across members of said pluralities of air supply and combustion gas discharge conduits to open and close said pluralities of air supply and combustion gas discharge conduits during reciprocation of said linked pair of multi-port slide valve members, means for actuating the reciprocation of said linked pair of multiport slide valve members, means for intermittently supplying a combustible fuel into said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within said piston chamber when said piston is near its top dead-center cyclic position, said method comprising the combinative steps of:

supplying pressurized combustion air into said air inlet means of said crankcase from the discharge of said fluid pump;

transforming rotary motion of said crankshaft to reciprocating motion of said linked pair of multi-port slide valve members in transmission means which communicates between said crankshaft and means linking said pair of multi-port slide valve members;

synchronizing the reciprocation of said linked pair of multiport slide valve members with rotation of said crankshaft, so that said linked pair of multi-port slide valve members continuously completes each reciprocating cycle in conjunction with completion of the designed rotation of said crankshaft;

flowing a charge of pressurized combustion air from said crankcase through said plurality of air supply conduits and said pair of opposite first cylinder ports into said piston chamber by way of said inlet ports of said linked pair of reciprocating multiport slide valve members, while discharging spent combustion gases from said piston chamber through said pair of opposite second cylinder ports and said plurality of combustion gas discharge conduits by way of said outlet ports of said linked pair of reciprocating multi-port slide valve members, while said piston is near its bottom dead-center cyclic position;

impelling the discharge of spent combustion gases from said piston chamber while said piston is near its bottom dead-center cyclic position, by admitting a charge of combustion air thereinto which displaces and expels spent combustion gases therefrom;

stopping the flow of combustion air into said piston chamber and discharge of fluids therefrom during the compression stroke of said piston, when said linked pair of reciprocating multi-port slide valve members cyclically closes said pluralities of air supply and combustion gas discharge conduits;

injecting a dispersed liquid fuel into said piston chamber, as said piston approaches its top dead-center cyclic position; and

igniting the compressed air-fuel mixture within said piston chamber by an electric spark, as said piston is near its top dead-center cyclic position.

15. The method of claim 14 wherein the said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of said piston chamber during its compression stroke, said engine having no spark ignition means, with the additional steps of:

compressing the combustion air charge supplied into said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into the heated air charge within said piston chamber, as said piston approaches its top dead-center cyclic position; and

spontaneously igniting the compressed air-fuel mixture within said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

16. A method for operating a reciprocating 2-stroke cycle multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers each with a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft with a plurality of crank pins disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a wrist pin disposed onto the low-pressure side of each said piston, a plurality of connecting rods each having one end pivotally connected onto a said wrist pin with the other end pivotally connected onto a corresponding said crank pin, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head of said engine block closing the high-pressure portion of said plurality of piston chambers, a cover closing said crankcase portion of said engine block, air inlet means disposed in said crankcase portion of said engine block, check valve means disposed in said air inlet means of said crankcase, a plurality of air supply conduits communicating between said crankcase and a plurality of cylinder ports disposed in an extended portion of each said piston chamber, said plurality of cylinder ports serving each said piston chamber being opened and closed by the sidewall of its corresponding said piston near its bottom dead-center cyclic position, a plurality of combustion gas discharge conduits communicating between an atmospheric exhaust outlet and a pair of opposite second cylinder ports of each said piston chamber which are each disposed adjacent said cylinder head, a linked pair of reciprocating multi-port slide valve members each having a plurality of outlet ports disposed therein for flow of gaseous fluids therethrough and slideably disposed opposite each other in guideway means of said engine block across said plurality of combustion gas discharge conduits to sequentially open and close members of said plurality of combustion gas discharge conduits serving each said piston chamber during reciprocation of said linked pair of multi-port slide valve members in accordance with the designed firing order of said engine, means for actuating the reciprocation of said linked pair of multi-port slide valve members, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, said method comprising the combinative steps of:

inducing the flow of atmospheric combustion air into said crankcase by the vacuum produced by said plurality of reciprocating pistons during their compression strokes;

pressurizing combustion air within said crankcase by said plurality of reciprocating pistons during their extending power strokes;

flowing a charge of combustion air from said crankcase through said plurality of air supply conduits and into each said piston chamber, when its said plurality of first cylinder ports are uncovered by its corresponding said piston near its bottom dead-center cyclic position;

transforming rotary motion of said crankshaft to reciprocating motion of said linked pair of multi-port slide valve members in transmission means which communicate between said crankshaft and means linking said pair of multi-port slide valve members;

synchronizing the reciprocation of said linked pair of multi-port slide valve members with the rotation of said crankshaft, so that said linked pair of multi-port slide valve members continuously completes each reciprocating cycle in conjunction with completion of the designed rotation of said crankshaft;

discharging spent combustion gases from each said piston chamber through its said pair of opposite second cylinder ports and corresponding members of said plurality of combustion gas discharge conduits by way of corresponding said outlet ports of said linked pair of multi-port slide valve members, while its corresponding said piston is near its bottom dead-center cyclic position;

impelling the discharge of spent combustion gases from each said piston chamber while its corresponding said piston is near its bottom dead-center cyclic position, by admitting a charge of combustion air thereinto which displaces and expels spent combustion gases therefrom;

stopping the discharge of gaseous fluids from each said piston chamber during the compression stroke of its corresponding said piston, when said linked pair of reciprocating multi-port slide valve members closes corresponding members of said plurality of combustion gas discharge conduits;

injecting a dispersed liquid fuel into each said piston chamber, as its corresponding said piston approaches its top dead-center cyclic position; and

igniting the compressed air-fuel mixture within each said piston chamber by an electric spark, when its corresponding said piston is near its top dead-center cyclic position.

17. The method of claim 16 wherein each said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its said piston chamber during its compression stroke, said engine having no spark ignition means, with the additional steps of:

compressing the combustion air charge supplied into each said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into the heated air charge within each said piston chamber, as its corresponding said piston approaches its top dead-center cyclic position; and

spontaneously igniting the compressed air-fuel mixture within each said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

18. A method for operating a reciprocating 2-stroke cycle multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers each with a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft with a plurality of crank pins disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a wrist pin disposed onto the low-pressure side of each said piston, a plurality of connecting rods each having one end pivotally connected onto a said wrist pin with the other end pivotally connected onto a corresponding said crank pin, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head of said engine block closing the high-pressure portion of said plurality of piston chambers, a cover closing the crankcase portion of said engine block, air inlet means disposed in said crankcase portion of said engine block, a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said crankcase, a plurality of air supply conduits communicating between said crankcase and a pair of opposite cylinder ports in each said piston chamber, a plurality of combustion gas discharge conduits communicating between an atmospheric exhaust outlet and a pair of opposite second cylinder ports of each said piston chamber which are each disposed adjacent said cylinder head, a linked pair of reciprocating multi-port slide valve members each having a plurality of inlet and outlet ports disposed therein for flow of gaseous fluids therethrough and slideably disposed opposite each other in guideway means of said engine block across said pluralities of air supply and combustion gas discharge conduits to sequentially open and close members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber during reciprocation of said linked pair of multi-port slide valve members in accordance with the designed firing order of said engine, means for actuating the reciprocation of said linked pair of multi-port slide valve members, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, said method comprising the combinative steps of:

supplying pressurized combustion air into said air inlet means of said crankcase from the discharge of said fluid pump;

transforming rotary motion of said crankshaft to reciprocating motion of said linked pair of multi-port slide valve members in transmission means which communicate between said crankshaft and means linking said pair of multi-port slide valve members;

synchronizing the reciprocation of said linked pair of multi-port slide valve members with rotation of said crankshaft, so that said linked pair of multi-port slide valve members continuously completes each reciprocating cycle in conjunction with completion of the designed rotation of said crankshaft;

sequentially flowing a charge of pressurized combustion air from said crankcase into each said piston chamber through corresponding members of said plurality of air supply conduits by way of said inlet ports of said linked pair of reciprocating multi-port slide valve members, while discharging spent combustion gases from the said piston chamber through corresponding members of said plurality of combustion gas discharge conduits by way of said outlet ports of said linked pair of reciprocating multiport slide valve members, as corresponding members of said pluralities of air supply and combustion gas discharge conduits are opened through said inlet and outlet ports of said linked pair of reciprocating multi-port slide valve members while the corresponding said piston is near its bottom dead-center cyclic position;

impelling the discharge of spent combustion gases from each said piston chamber while its corresponding said piston is near its bottom dead-center cyclic position, by admitting pressurized combustion air into the piston chamber which displaces and expels spent combustion gases therefrom;

stopping the flow of pressurized combustion air into each said piston chamber and the discharge of gaseous fluids therefrom during the compression stroke of its corresponding said piston, when the said linked pair of reciprocating multi-port slide valve members cyclically close corresponding members of said pluralities of air supply and combustion gas discharge conduits serving the said piston chamber;

injecting a dispersed liquid fuel into each said piston chamber, as its corresponding said piston approaches its top dead-center cyclic position; and

igniting the compressed air-fuel mixture within each said piston chamber by an electric spark, as its corresponding said piston is near its top dead-center cyclic position.

19. The method of claim 18 wherein each said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its said piston chamber during its compression stroke, said engine having no spark ignition means, with the additional steps of:

compressing the combustion air charge supplied into each said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into the heated air charge within each said piston chamber, as its corresponding said pistons approaches its top dead-center cyclic position; and

spontaneously igniting the compressed air-fuel mixture within each said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

20. A reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber having a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft having a plurality of crank pins and disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a plurality of wrist pins having members individually disposed onto the low-pressure side of each member of said plurality of reciprocating pistons, a plurality of connecting rods each having one end pivotally connected onto a said wrist pin with the other end pivotally connected onto a corresponding said crank pin, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head of said engine block closing the high-pressure portion of said plurality of piston chambers, a cover closing said crankcase portion of said engine block, a plurality of air supply conduits each communicating between a source of combustion air and a plurality of inlet cylinder ports of each member of said plurality of piston chambers, a plurality of combustion gas discharge conduits each communicating between an atmospheric exhaust outlet and a plurality of outlet cylinder ports of each member of said plurality of piston chambers, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic positions comprising in combination:

said plurality of inlet cylinder ports of each said piston chamber being individually disposed in the sidewall of said piston chamber so as to be substantially uncovered by the sidewall of its corresponding said piston near its bottom dead-center cyclic position and substantially covered by the sidewall of said piston during its compression stroke, and said plurality of outlet cylinder ports being individually disposed in the sidewall of each said piston chamber adjacent said cylinder head;

a pair of multi-port slide valve members having opposite members which are linked together and slideably disposed on opposite sides of each said piston chamber in guideway means of said engine block, and disposed therein to reciprocate together;

transmission means communicating between said crankshaft and means linking the members of said pair of multi-port slide valve members and disposed to continuously convert rotary motion to reciprocating motion, so that members of said pair of oppositely-disposed multi-port slide valve members reciprocate together and continuously complete each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

members of said pair of reciprocating multi-port slide valve members being disposed across corresponding members of said plurality of combustion gas discharge conduits which communicate with corresponding members of said plurality of outlet cylinder ports of each member of said plurality of piston chambers, to intermittently open and close corresponding members of said plurality of combustion gas discharge conduits serving each said piston chamber during reciprocation of said pair of opposite multiport slide valve members; and

members of said pair of reciprocating opposite multi-port slide valve members having companion sets of outlet ports for passage of fluids therethrough and disposed therein so that corresponding said combustion gas discharge conduits serving each said piston chamber are intermittently opened in sequence during reciprocation of said pair of opposite multi-port slide valve members when each corresponding said piston is near its bottom dead-center cyclic position, and spent combustion gases are sequentially discharged from each said piston chamber;

whereby each member of said plurality of piston chambers is sequentially purged of spent combustion gases by a charge of fresh combustion air while its corresponding said piston is near its bottom dead-center cyclic position, as corresponding members of said plurality of combustion gas discharge conduits are opened through corresponding said outlet ports of said reciprocating pair of opposite multi-port slide valve members, and corresponding said members of said plurality of combustion gas discharge conduits serving each said piston chamber are intermittently closed in sequence by members of said pair of reciprocating multi-port slide valve members during the compression stroke of each corresponding said piston.

21. The reciprocating multi-cylinder internal combustion engine of claim 20 wherein a plurality of liquid fuel injectors is disposed in said cylinder head, each member of said plurality of liquid fuel injectors having its outlet exposed into a corresponding member of said plurality of piston chambers, a fluid pump is disposed to supply high-pressure liquid fuel through communicating conduit means into an inlet of each said fuel injector,, valve means@are disposed in a fuel supply conduit branch serving each said fuel injector, and valve operating means is disposed to intermittently open each said valve means serving each said fuel injector and discharge high-pressure liquid fuel into its corresponding said piston chamber, when its corresponding said piston approaches its top dead-center cyclic position.

22. The reciprocating multi-cylinder internal combustion engine of claim 20 wherein a plurality of electrical spark plugs is disposed in said cylinder head, each member of said plurality of electrical spark plugs having its electrodes exposed into a corresponding member of said plurality of piston chambers, a source of high-voltage electrical current, electrical conductor means communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, and electrical switch means disposed in a conductor branch communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, to intermittently energize electrodes of each said electrical spark plug and ignite the compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position.

23. The reciprocating multi-cylinder internal combustion engine of claim 20 wherein each said piston member closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its corresponding said piston chamber, and the heat of compression from work done on a combustion air charge by each said piston member elevates combustion air temperature above the fuel ignition temperature to spontaneously ignite a combustible fuel supplied into its corresponding said piston chamber.

24. The reciprocating multi-cylinder internal combustion engine of claim 20 wherein members of a pair of opposite exterior exhaust manifolds are individually disposed to communicate with corresponding members of said plurality of combustion gas discharge conduits serving members of said plurality of outlet cylinder ports of each member of said plurality of piston chambers from opposite sides of said engine block, and said pair of opposite exterior exhaust manifolds collect the combined exhaust of spent combustion gases discharged from said outlet cylinder ports of said plurality of piston chambers.

25. A reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber having a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft having a plurality of crank pins and disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a plurality of wrist pins having members individually disposed onto the low-pressure side of each member of said plurality of reciprocating pistons, a plurality of connecting rods each having one end pivotally connected onto a said wrist pin with the other end pivotally connected onto a corresponding said crank pin, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head of said engine block closing the high-pressure portion of said plurality of piston chambers, a cover closing said crankcase portion of said engine block, a plurality of air supply conduits each communicating between a source of combustion air and a plurality of inlet cylinder ports of each member of said plurality of piston chambers, a plurality of combustion gas discharge conduits each communicating between an atmospheric exhaust outlet and a plurality of outlet cylinder ports of each member of said plurality of piston chambers, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, comprising in combination:

said plurality of inlet cylinder ports being individually disposed in the sidewall of each said piston chamber in a lower portion thereof, and said plurality of outlet cylinder ports being individually disposed in the sidewall of each said piston chamber adjacent said cylinder head;

a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said plurality of air supply conduits serving each said piston chamber;

a pair of multi-port slide valve members having opposite members which are linked together and slideably disposed on opposite sides of each said piston chamber in guideway means of said engine block, and disposed therein to reciprocate together;

transmission means communicating between said crankshaft and means linking the members of said pair-of multi-port slide valve members and disposed to continuously convert rotary motion to reciprocating motion, so that members of said pair of oppositely-disposed multi-port slide valve members reciprocate together and continuously complete each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

members of said linked pair of reciprocating multi-port slide valve members each having a plurality of inlet ports for flow of combustion air therethrough and a plurality of outlet ports for flow of combustion gases therethrough, and disposed across members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber to intermittently open and close members of said pluralities of air supply and combustion gas discharge conduits during reciprocation of said linked pair of reciprocating multi-port slide valve members; and

members of said pluralities of inlet and outlet ports of said members of the linked pair of reciprocating multi-port slide valve members being disposed in each said slide valve member in companion sets to sequentially open each member of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber, and supply a charge of pressurized combustion air into each said piston chamber while discharging spent combustion gases therefrom as its corresponding said piston is near its bottom dead-center cyclic position;

whereby a charge of combustion air is sequentially admitted through said plurality of inlet cylinder ports into each said piston chamber of said multi-cylinder engine while spent combustion gases are discharged through its said plurality of outlet cylinder ports, as corresponding members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber are opened through said companion sets of inlet and outlet ports of said linked pair of reciprocating multi-port slide valve members and members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber are substantially closed by said linked pair of reciprocating multi-port slide valve members during the compression stroke of the corresponding said piston.

26. The reciprocating multi-cylinder internal combustion engine of claim 25 wherein a plurality of liquid fuel injectors is disposed in said cylinder head, each member of said plurality of liquid fuel injectors having its outlet exposed into a corresponding member of said plurality of piston chambers, a fluid pump is disposed to supply high-pressure liquid fuel through communicating conduit means into an inlet of each said fuel injector, valve means are disposed in a fuel supply conduit branch serving each said fuel injector, and valve operating means is disposed to intermittently open each said valve means serving each said fuel injector and discharge high-pressure liquid fuel into its corresponding said piston chamber, when its corresponding said piston approaches its top dead-center cyclic position.

27. The reciprocating multi-cylinder internal combustion engine of claim 25 wherein a plurality of electrical spark plugs is disposed in said cylinder head, each member of said plurality of electrical spark plugs having its electrodes exposed into a corresponding member of said plurality of piston chambers, a source of high-voltage electrical current, electrical conductor means communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, and electrical switch means disposed in a conductor branch communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, to intermittently energize electrodes of each said electrical spark plug and ignite the compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position.

28. The reciprocating multi-cylinder internal combustion engine of claim 25 wherein each said piston member closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its corresponding said piston chamber, and the heat of compression from work done on a combustion air charge by each said piston member elevates combustion air temperature above the fuel ignition temperature to spontaneously ignite a combustible fuel supplied into its corresponding said piston chamber.

29. The reciprocating multi-cylinder internal combustion engine of claim 25 wherein air inlet means are disposed in said crankcase portion of said engine block, the said fluid pump is disposed to supply pressurized combustion air into said air inlet means of said crankcase, and members of said plurality of air supply conduits communicate with said crankcase.

30. A method for operating a reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers each with a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft having a plurality of crank pins and disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a wrist pin disposed on the low-pressure side of each said reciprocating piston, a plurality of connecting rods each having one end pivotally connected onto a said wrist pin with the other end pivotally connected onto a corresponding said crank pin, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head of said engine block closing the high-pressure portion of said plurality of piston chambers, a cover, closing said crankcase portion of said engine block, air inlet means disposed in said crankcase portion of said engine block, check valve means disposed in said air inlet means to admit atmospheric air into said crankcase, a plurality of air supply conduits communicating between said crankcase and a plurality of inlet cylinder ports disposed in an extended portion of each said piston chamber, said plurality of inlet cylinder ports serving each said piston chamber being opened and closed by the sidewall of its corresponding said piston near its bottom dead-center cyclic position, a plurality of combustion gas discharge conduits communicating between an atmospheric exhaust outlet and a plurality of outlet cylinder ports of each said piston chamber which are disposed adjacent said cylinder head, a linked pair of reciprocating multiport slide valve members each having a plurality of outlet ports disposed therein for flow of gaseous fluids therethrough, members of said linked pair of said reciprocating slide valve members being slideably disposed in guideway means of said engine block on opposite sides of said plurality of piston chambers and disposed across members of said plurality of combustion gas discharge conduits to sequentially open and close members of said plurality of combustion gas discharge-conduits serving each said piston chamber during reciprocation of said linked pair of multi-port slide valve members in accordance with the designed firing order of said engine, means for actuating the reciprocation of said linked pair of multi-port slide valve members, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, said method comprising the combinative steps of:

inducing the flow of atmospheric combustion air into said crankcase by the vacuum produced by members of said plurality of reciprocating pistons during their compression strokes;

pressurizing combustion air within said crankcase by the pressure pulses produced by members of said plurality of reciprocating pistons during their expansion strokes;

flowing a charge of combustion air from said crankcase through members of said plurality of air supply conduits and into each said piston chamber, when its said plurality of inlet cylinder ports are uncovered by the sidewall of its corresponding said piston;

transforming rotary motion of said crankshaft to reciprocation of said linked pair of multi-port slide valve members in transmission means which communicate between said crankshaft and means linking said pair of multi-port slide valve members;

synchronizing the reciprocation of said linked pair of multiport slide valve members with rotation of said crankshaft, so that said linked pair of multi-port slide valve members continuously completes each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

discharging spent combustion gases from each said piston chamber through its said plurality of outlet cylinder ports and corresponding members of said plurality of combustion gas discharge conduits by way of corresponding said outlet ports of said linked pair of reciprocating multi-port slide valve members, when its corresponding said piston is near its bottom dead-center cyclic position;

impelling the discharge of spent combustion gases from each said piston chamber while its corresponding said piston is near its bottom dead-center cyclic position, by admitting a charge of combustion air thereinto which displaces and expels spent combustion gases therefrom;

stopping the discharge of gaseous fluids from each said piston chamber during the compression stroke of its corresponding said piston, when said linked pair of reciprocating multi-port slide valve members cyclically closes corresponding members of said plurality of combustion gas discharge conduits serving the corresponding said piston chamber;

intermittently injecting a dispersed liquid fuel into each said i piston chamber, during the compression stroke of its correspond-said piston; and

intermittently igniting the compressed air-fuel mixture within each said piston chamber by an electric spark, as its corresponding said piston is near its top dead-center cyclic position.

31. The method of claim 30 wherein each said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its said piston chamber during its compression stroke, said engine having no spark ignition means, with the additional steps of:

compressing the combustion air charge supplied into each said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into each said piston chamber during the compression stroke of its corresponding said piston; and

spontaneously igniting the compressed air-fuel mixture within each said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

32. The method of claim 30 wherein the outlet of a fluid pump communicates with said ail, inlet means, and pressurized combustion air is supplied into said crankcase.

33. A method for operating a reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers each with a reciprocating piston disposed therewithin to compress and expand gaseous fluids, a rotary crankshaft having a plurality of crank pins and disposed in a crankcase portion of said engine block on the low-pressure side of said plurality of piston chambers, a wrist pin disposed onto the low-pressure side of each said reciprocating piston, a plurality of connecting rods each having one end pivotally connected onto a said wrist pin with the other end pivotally connected onto a corresponding said crank pin, each said connecting rod disposed to transmit a variable torque to said crankshaft during reciprocation of its corresponding said piston, a cylinder head of said engine block closing the high-pressure portion of said plurality of piston chambers, a cover closing said crankcase portion of said engine block, air inlet means disposed in said crankcase portion of said engine block, a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said crankcase, a plurality of air supply conduits communicating between said crankcase and a plurality of inlet cylinder ports in each said piston chamber, a plurality of combustion gas discharge communicating between an atmospheric exhaust outlet and a plurality of outlet cylinder ports in each said piston chamber which are disposed adjacent said cylinder head, a linked pair of reciprocating multi-port slide valve members each having a plurality of companion inlet and outlet ports disposed therein for flow of gaseous fluids therethrough, members of said linked pair of reciprocating multi.-port slide valve members being slideably disposed in guideway means of said engine block on opposite sides of said plurality of piston chambers and disposed across members of said pluralities of air supply and combustion gas discharge conduits to sequentially open and close members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber during reciprocation of said linked pair of multi-port slide valve members in accordance with the designed firing order of said engine, means for actuating the reciprocation of said linked pair of multi-port slide valve members, means for intermittently supplying a combustible fuel into each said piston chamber, and means for, intermittently igniting a compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position, said method comprising the combinative steps of:

transforming rotary motion of said crankshaft to reciprocating motion of said linked pair of multi-port slide valve members in transmission means which communicate between said crankshaft and means linking said pair of multi-port slide valve members;

synchronizing the reciprocation of said linked pair of multi-port slide valve members with rotation of said crankshaft, so that said linked pair of multi-port slide valve members continuously completes each reciprocating cycle in accordance with completion of a designed rotation of said crankshaft;

sequentially flowing a charge of pressurized combustion air from said crankcase into each said piston chamber through corresponding members of said plurality of air supply conduits by way of said inlet ports of said linked pair of reciprocating multi-port slide valve members, while discharging spent combustion gases from the said piston chamber through corresponding members of said plurality of combustion gas discharge conduits by way of said outlet ports of said linked pair of reciprocating multiport slide valve members, as corresponding members of said pluralities of air supply and combustion gas discharge conduits are opened through said inlet and outlet ports of said linked pair of reciprocating multi-port slide valve members while the corresponding said piston is near its bottom dead-center cyclic position;

impelling the discharge of spent combustion gases from each said piston chamber while its corresponding said piston is near its bottom dead-center cyclic position,, by admitting pressurized combustion air into the piston chamber which displaces and expels spent combustion gases therefrom;

stopping the flow of pressurized combustion air into each said piston chamber and the discharge of gaseous fluids therefrom during the compression stroke of its corresponding said piston, when the said linked pair of reciprocating multi-port slide valve members cyclically close corresponding members of said pluralities of air supply and combustion gas discharge conduits serving the said piston chamber;

injecting a dispersed liquid fuel into each said piston chamber, during the compression stroke of its corresponding said piston; and

igniting the compressed air-fuel mixture within each said piston chamber by an electric spark, as its corresponding said piston is near its top dead-center cyclic position.

34. The method of claim 33 wherein each said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its said piston chamber during its compression stroke, said engine having no spark ignition, means, with the additional steps of:

compressing the combustion air charge supplied into each said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into each said piston chamber-during the compression stroke of its corresponding said piston; and

spontaneously igniting the compressed air-fuel mixture within each said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

35. A reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber closed by a cylinder head at its high-pressure end and having a reciprocating piston slideably disposed therein to compress and expand gaseous fluids, each reciprocating piston disposed to transmit an intermittent torque to a rotating output crankshaft of said engine, means for intermittently supplying combustion air, and a combustible fuel into each said piston chamber, means for intermittently igniting a compressed air-fuel mixture within each said piston chamber, and means for intermittently discharging spent combustion gases from each said piston chamber, comprising in combination:

a plurality of air inlet cylinder ports disposed adjacent said cylinder head in each said piston chamber, for passage of combustion air thereinto;

a plurality of gas outlet cylinder ports disposed in an extended portion of each said piston chamber opposite from said plurality of air inlet cylinder ports, for discharge of spent combustion gases therefrom;

a pair of exhaust manifolds each having inlet and outlet means, whose members are disposed on opposite sides of said engine block

conduit means communicating between members of said plurality of air inlet cylinder ports of each said piston chamber and said air inlet means of said engine;

conduit means communicating between members of said plurality of gas outlet cylinder ports of each said piston chamber and said inlet means of each said exhaust manifold;

a pair of multi-port slide valve members having opposite members which are linked together and slideably disposed on opposite sides of each said piston chamber in guideway means of said engine block, and disposed therein to reciprocate together;

transmission means communicating between said crankshaft and means linking members of said pair of multi-port slide valve members and disposed to continuously convert rotary motion to reciprocating motion, so that members of said pair of oppositely-disposed multi-port slide valve members reciprocate together and continuously complete each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

members of said linked pair of reciprocating multi-port slide valve members each having a plurality of inlet ports for flow of combustion air therethrough and a plurality of outlet ports for flow of combustion gases therethrough, and disposed across corresponding members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber from opposite sides thereof to intermittently open and close members of said pluralities of air supply and combustion gas discharge conduits during reciprocation of said linked pair of reciprocating multi-port slide valve members; and

members of said pluralities of inlet and outlet ports of said members of the linked pair of reciprocating multi-port slide valve members being disposed in each said slide valve member in companion sets to sequentially open each member of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber from opposite sides thereof, and supply a charge of pressurized combustion air into each said piston chamber from opposite sides thereof while discharging spent combustion gases from each said piston chamber from opposite sides thereof as its corresponding said piston is near its bottom dead-center cyclic position;

whereby a charge of combustion air is sequentially admitted through members of said plurality of air inlet cylinder ports into each said piston chamber while spent combustion gases are discharged through members of said plurality of gas outlet cylinder ports from each said piston chamber, as corresponding members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber from opposite sides thereof are opened through said companion sets of inlet and outlet ports of said linked pair of reciprocating multi-port slide valve members, and members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber are sequentially closed by said linked pair of reciprocating multi-port slide valve members during the compression stroke of the corresponding said piston.

36. The reciprocating multi-cylinder internal combustion engine of claim 35 wherein members of the said plurality of gas outlet cylinder ports serving each said piston chamber are disposed adjacent said cylinder bead, and members of said plurality of air inlet cylinder ports serving each said piston chamber are disposed in an extended portion thereof opposite from members of said plurality of gas outlet cylinder ports.

37. The reciprocating multi-cylinder internal combustion engine of claim 35 wherein a fluid pump is disposed to supply pressurized combustion air into said air inlet means of said engine.

38. The reciprocating multi-cylinder internal combustion engine of claim 35 wherein a plurality of liquid fuel injectors is disposed in said cylinder head, each member of said plurality of liquid fuel injectors having its outlet exposed into a corresponding member of said plurality of piston chambers, a fluid pump is disposed to supply high-pressure liquid fuel through communicating conduit means into an inlet of each said fuel injector, valve means are disposed in a fuel supply conduit branch serving each said fuel injector, and valve operating means is disposed to intermittently open each said valve means serving each said fuel injector and discharge high-pressure liquid fuel into its corresponding said piston chamber, when its corresponding said piston approaches its top dead-center cyclic position.

39. The reciprocating multi-cylinder internal combustion engine of claim 35 wherein a plurality of electrical spark plugs is disposed in said cylinder head, each member of said plurality of electrical spark plugs having its electrodes exposed into a corresponding member of said plurality of piston chambers, a source of high-voltage electrical current,, electrical conductor means communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, and electrical switch means disposed in a conductor branch communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, to intermittently energize electrodes of each said electrical spark plug and ignite the compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position.

40. The reciprocating multi-cylinder internal combustion engine of claim 35 wherein each said piston member closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its corresponding said piston chamber, and the heat of compression from work done on a combustion air charge by each said piston member elevates combustion air temperature above the fuel ignition temperature to spontaneously ignite a combustible fuel supplied into its corresponding said piston chamber.

41. The reciprocating multi-cylinder internal combustion engine of claim 35 wherein a fluid pump is disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said engine and members of said plurality of piston chambers.

42. A reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber closed by a cylinder head at its high-pressure end and having a reciprocating piston slideably disposed therein to compress and expand gaseous fluids, each reciprocating piston disposed to transmit an intermittent torque to a rotating output crankshaft of said engine, means for intermittently supplying combustion air and a combustible fuel into each said piston chamber, means for intermittently igniting a compressed air-fuel mixture within each said piston chamber, and means for intermittently discharging spent combustion gases from each said piston chamber, comprising in combination:

a plurality of air inlet cylinder ports disposed adjacent said cylinder head in each said piston chamber, for passage of combustion air thereinto;

a plurality of gas outlet cylinder ports disposed in an extended portion of each said piston chamber opposite from said plurality of air inlet cylinder ports, for discharge of spent combustion gases therefrom;

a pair of air-preheating manifold heat exchangers whose members are disposed on opposite sides of said engine block, each said manifold heat exchanger having separated fluid passageways confining flow therethrough of combustion air supplied into each said piston chamber and combustion gases discharged from each said piston chamber, air inlet and outlet means, combustion gas inlet and outlet means, and being adapted to transfer heat there within between discharge flows of hot combustion gases and cooler incoming flows of combustion air;

conduit means communicating between members of said plurality of air inlet cylinder ports of each said piston chamber and said air outlet means of members of said pair of oppositely-disposed manifold heat exchangers;

conduit means communicating between members of said plurality of gas outlet cylinder ports of each said piston chamber and said gas inlet means of members of said pair of oppositely-disposed manifold heat exchangers;

members of said pair of manifold heat exchangers disposed to supply preheated combustion air into said conduit air supply means communicating with members of said plurality of air inlet cylinder ports of said plurality of piston chambers from opposite sides thereof, and collect the combined discharge of hot combustion gases from said conduit means communicating with said gas outlet cylinder ports of said plurality of piston chambers from opposite sides thereof;

a pair of multi-port slide valve members having opposite members which are linked together and slideably disposed on opposite sides of each said piston chamber in guideway means of said engine block, and disposed therein to reciprocate together;

transmission means communicating between said crankshaft and means linking members of said pair of multi-port slide valve members and disposed to continuously convert rotary motion to reciprocating motion, so that members of said pair of oppositely-disposed multi-port slide valve members reciprocate together and continuously complete each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of each member of said pair of oppositely-disposed manifold heat exchangers;

members of said linked pair of reciprocating multi-port slide valve members each having a plurality of inlet ports for flow of combustion air therethrough and a plurality of outlet ports for flow of combustion gases therethrough, and disposed across corresponding members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber from opposite sides thereof to intermittently open and close members of said pluralities of air supply and combustion gas discharge conduits during reciprocation of said linked pair of reciprocating multi-port slide valve members; and

members of said pluralities of inlet and outlet ports of said members of the linked pair of reciprocating multi-port slide valve members being disposed in each said slide valve member in companion sets to sequentially open each member of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber from opposite sides thereof, and supply a charge of pressurized preheated combustion air into each said piston chamber from opposite sides thereof while discharging spent combustion gases from each said piston chamber from opposite sides thereof as its corresponding said piston is near its bottom dead-center cyclic position;

whereby a charge of preheated combustion air is sequentially admitted through members of said plurality of air inlet cylinder ports into each said piston chamber while spent combustion gases are discharged through members of said plurality of gas outlet cylinder ports from each said piston chamber, as corresponding members of said pluralities of air supply and combustion gas discharge conduit serving each said piston chamber from opposite sides thereof are opened through said companion sets of inlet and outlet ports of said linked pair of reciprocating multi-port slide valve members, and members of said pluralities of air supply and combustion gas discharge conduits serving each said piston chamber are sequentially closed by said linked pair of reciprocating multi-port slide valve members during the compression stroke of the corresponding said piston.

43. The reciprocating multi-cylinder internal combustion engine of claim 42 wherein members of the said plurality of gas outlet cylinder ports serving each said piston chamber are disposed adjacent said cylinder head, and members of said plurality of air inlet cylinder ports serving each said piston chamber are disposed in an extended portion thereof opposite from members of said plurality of gas outlet cylinder ports.

44. The reciprocating multi-cylinder internal combustion engine of claim 42 wherein a plurality of liquid fuel injectors is disposed in said cylinder head, each member of said plurality of liquid fuel injectors having its outlet exposed into a corresponding member of said plurality of piston chambers, a fluid pump is disposed to supply high-pressure liquid fuel through communicating conduit means into an inlet of each said fuel injector, valve means are disposed in a fuel supply conduit branch serving each said fuel injector, and valve operating means is disposed to intermittently open each said valve means serving each said fuel injector and discharge high-pressure liquid fuel into its corresponding said piston chamber, when its corresponding said piston approaches its top dead-center cyclic position.

45. The reciprocating multi-cylinder internal combustion engine of claim 42 wherein a plurality of electrical spark plugs is disposed in said cylinder head, each member of said plurality of electrical spark plugs having its electrodes exposed into a corresponding member of said plurality of piston chambers, a source of high-voltage electrical current, electrical conductor means communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, and electrical switch means disposed in a conductor branch communicating between said source of high-voltage electrical current and a terminal of each said electrical spark plug, to intermittently energize electrodes of each said electrical spark plug and ignite the compressed air-fuel mixture within each said piston chamber when its corresponding said piston is near its top dead-center cyclic position.

46. The reciprocating multi-cylinder internal combustion engine of claim 42 wherein each said piston member closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its corresponding said piston chamber, and the heat of compression from work done on a combustion air charge by each said piston member elevates combustion air temperature above the fuel ignition temperature to spontaneously ignite a combustible fuel supplied into its corresponding said piston chamber.

47. A reciprocating 2-stroke cycle multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber closed by a cylinder head at its high-pressure end and having a reciprocating piston slideably disposed therein to compress and expand gaseous fluids, each said reciprocating piston disposed to transmit an intermittent torque to a rotating output crankshaft of said engine, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber, comprising in combination:

an air inlet cylinder port disposed in a portion of each said piston chamber and extending through said engine block on one side thereof, for intermittent supply of combustion air into each said piston chamber;

a gas outlet cylinder port disposed in a second portion of each said piston chamber and extending through said engine block on one side thereof, for intermittent discharge of hot combustion gases from each said piston chamber;

a multi-port slide valve member slideably disposed to reciprocate in guideway means on one side of said engine block said multi-port slide valve member having separate pairs of upper and lower ports extending therethrough and disposed to sequentially open and close said air inlet and gas outlet cylinder ports of members of said plurality of piston chambers from one side of said engine block, when said multi-port slide valve member reciprocates;

transmission means communicating between said crankshaft and said multi-port slide valve member and disposed to continuously convert rotary motion to reciprocating motion, so that said multiport slide valve member completes each reciprocating cycle in conjunction with each complete rotation of said crankshaft;

an air-preheating manifold heat exchange having separate internal fluid passageways for transit of pressurized combustion air and hot combustion gases therethrough, and disposed on one side of said engine block adjacent said plurality of piston chambers;

said manifold heat exchanger having air inlet means communicating with a first internal plenum which communicates with an elongate air outlet slot, said first internal plenum disposed to receive pressurized combustion air and intermittently distribute a charge of pressurized combustion air through said air outlet slot into a corresponding said air inlet cylinder port of each member of said plurality of piston chambers, when a respective first member of a said pair of upper and lower ports of said multi-port slide valve member is oppositely-adjacent a corresponding said air inlet cylinder port of each said piston chamber to permit a charge of pressurized combustion air to flow therethrough from said first internal plenum of said manifold heat exchanger, during reciprocation of said multi-port slide valve member;

said manifold heat exchange having an elongate gas inlet slot communication with a second internal plenum which communicates with a gas outlet means, said second internal plenum disposed to intermittently receive hot combustion gases by way of said gas inlet slot from a corresponding said gas outlet cylinder port of each member of said plurality of piston chambers, when a respective second member of a said pair of upper and lower ports of said multi-port slide-valve member is oppositely-adjacent a corresponding said gas outlet port of each said piston chamber to permit an intermittent flow of hot combustion gases therethrough and into said second internal plenum of said manifold heat exchanger, during reciprocation of said multi-port slide valve member;

a fluid pump is disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said manifold heat exchanger; and

exhaust conduit means communicating with said gas outlet means of said manifold heat exchanger for discharging spent combustion gases to atmosphere;

whereby heat from hot combustion gases intermittently discharged in sequence form corresponding said gas outlet cylinder ports of members of said plurality of piston chambers and flowing through said second internal plenum of said manifold heat exchanger is absorbed by the confining walls thereof, heat is transferred by conduction and convection to preheat pressurized combustion air flowing through said first internal plenum of said manifold heat exchanger, and preheated pressurized combustion air is intermittently supplied in sequence through corresponding said air inlet cylinder ports into members of said plurality of piston chambers.

48. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 47 wherein:

said air inlet cylinder port of each said piston chamber is disposed adjacent said cylinder head;

said gas outlet cylinder port of each said piston chamber is disposed in a low-pressure portion thereof adjacent the head its said piston, when said piston is at an extended position;

said upper port members of said pairs of upper and lower ports of said multi-port slide valve member are disposed linearly adjacent said air inlet cylinder ports of said plurality of piston chambers;

said lower port members of said pairs of upper and lower ports of said multi-port slide valve member are disposed linearly adjacent said gas outlet cylinder ports of said plurality of piston chambers;

said elongate air outlet slot of said manifold heat exchanger is disposed linearly adjacent said upper port members of said pairs of upper and lower ports of said multi-port slide valve member, to permit an intermittent change of pressurized preheated combustion air from said first internal plenum of said manifold heat exchanger to sequentially flow through a respective said air inlet cylinder port into each said piston chamber; and

said elongate gas inlet slot of said manifold heat exchanger is disposed linearly adjacent said lower port members of said pairs of upper and lower ports of said multi-port slide valve member, to permit an intermittent discharge of hot combustion gases to flow in sequence from said gas outlet cylinder port of each said piston chamber into said second internal plenum of said manifold heat exchanger.

50. The reciprocating 2-stroke cycle multi-cylinder internal combustion engine of claim 48 wherein:

said oppositely-disposed air inlet cylinder ports of each said piston chamber are disposed adjacent said cylinder head;

said opposite-disposed gas outlet cylinder ports of each said piston chamber are disposed in a low-pressure portion thereof adjacent the head of its said piston, when said piston is at an extended position;

said upper port members of said pairs of upper and lower ports of each said multi-port slide valve member are disposed linearly adjacent said air inlet cylinder ports on each side of said plurality of piston chambers;

said lower port members of said pairs of upper and lower ports of each said multi-port slide valve member are disposed linearly adjacent said gas outlet cylinder ports on each side of said plurality of piston chambers;

said elongate air outlet slot of each said manifold heat exchanger is disposed linearly adjacent said upper port members of said pairs of upper and lower ports of its respective said multi-port slide valve member on the same side of said plurality of piston chambers, to permit an intermittent charge of pressurized preheated combustion air from said first internal plenums of said oppositely-disposed pair of manifold heat exchangers to sequentially flow through a respective said air inlet cylinder port into each said piston chamber from opposite sides thereof; and

said elongate gas inlet slot of each said manifold heat exchanger is disposed linearly adjacent said lower ports members of said pairs of upper and lower ports of its respective said multi-port slide valve member on the same side of said plurality of piston chambers, to permit an intermittent discharge of hot combustion gases to flow in sequence form said gas outlet cylinder ports on the same side of said plurality of piston chambers into said second internal plenum of each said oppositely-disposed manifold heat exchanger.

49. A reciprocating 2-stroke cycle multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers, each said piston chamber closed by a cylinder heat at its high-pressure end and having a reciprocating piston slideably disposed therein to compress and expand gaseous fluids, each said reciprocating piston disposed to transmit an intermittent torque to a rotating output crankshaft of said engine, means for intermittently supplying a combustible fuel into each said piston chamber, and means for intermittently igniting a compressed air-fuel mixture within each said piston chamber, comprising in combination:

a pair of air inlet cylinder ports oppositely-disposed with respect to each other and extending through said engine block into a portion of each said piston chamber from opposite sides thereof, for intermittent supply of combustion air into each said piston chamber;

a pair of gas outlet cylinder ports oppositely-disposed with respect to each other and extending through said engine block into a second portion of each said piston chamber from opposite sides thereof, for intermittent discharge of hot combustion gases from each said piston chamber;

a pair of multi-port slide valve members having separated members which are linked together and slideably disposed on opposite sides of each said piston chamber in guideway means of said engine block to reciprocate together, each said slide valve member having separate pairs of upper and lower ports extending therethrough and disposed to sequentially open and close said air inlet and gas outlet cylinder ports on opposite sides of each said piston chamber, when said linked pair of multi-port slide valve members reciprocate together;

transmission means communicating between said crankshaft and means linking members of said pair of multi-port slide valve members and disposed to continuously convert rotary motion to reciprocating motion, so that said linked pair of multi-port slide valve members completes each reciprocating cycle in conjunction with each complete rotation of said crankshaft;

a pair of air-preheating manifold heat exchangers, each having separated internal fluid passageways for transit of pressurized combustion air and hot combustion gases therethrough, and oppositely-disposed with respect to each other on opposite sides of said engine block adjacent said plurality of piston chambers;

each said manifold heat exchanger having air inlet means communicating with a first internal plenum which communicates with an elongate air outlet slot, said first internal plenum disposed to receive pressurized combustion air and intermittently distribute a charge of pressurized combustion air through said air outlet slot into a corresponding said air inlet cylinder port of each member of said plurality of piston chambers, when a respective first member of a said pair of upper and lower ports of the corresponding said multi-port slide valve member is oppositely-adjacent a corresponding said air inlet cylinder port on the same side of each said piston chamber to permit a charge of pressurized combustion air to flow therethrough from said first internal plenum of the corresponding said manifold heat exchanger, during reciprocation of said linked pair of multi-port slide valve members;

each said manifold heat exchanger having an elongate gas inlet slot communicating with a second internal plenum which communicates with a gas outlet means, said second internal plenum disposed to intermittently receive hot combustion gases by way of said gas inlet slot from a corresponding said gas outlet cylinder port on the same side of each member of said plurality of piston chambers, when a respective second member of pair of upper and lower ports of the corresponding said multi-port slide valve member is oppositely-adjacent a respective said gas outlet cylinder port on the same side of each said piston chamber to permit an intermittent flow of hot combustion gases therethrough and into said second internal plenum of the corresponding said manifold heat exchanger, during reciprocation of said linked pair of multi-port slide valve members;

a fluid pump is disposed to supply pressurized combustion air thrust communicating conduit means into said air inlet means of each said manifold heat exchanger; and

exhaust conduit means communicating with said gas outlet means of each said manifold heat exchanger, for discharging spent combustion gases to atmosphere;

whereby heat from hot combustion gases intermittently discharged in sequence from corresponding said gas outlet cylinder ports on opposite sides of each member of said plurality of piston chambers and flowing through said second internal plenum of each said manifold heat exchanger is absorbed by the confining walls thereof, heat is transferred by conduction and convection to preheat pressurized combustion air flowing through said first internal plenum of each said manifold heat exchanger, and pressurized preheated combustion air is intermittently supplied in sequence through corresponding said opposite air inlet cylinder ports into each said piston chamber from opposite sides of said engine block.

51. A method for operating a reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers;

each said piston chamber closed by a cylinder head at its high-pressure end and having a reciprocating piston slideably disposed therein to compress and expand gaseous fluids;

conduit means for intermittently supplying combustion air into each said piston chamber;

means for intermittently supplying a combustible fuel into each said piston chamber;

means for intermittently igniting a compressed air-fuel mixture within each said piston chamber;

conduit means for intermittently discharging spent combustion gases from each said piston chamber;

a reciprocating multi-port slide valve member slideably disposed in guideway means of said engine block across said conduit air supply means and said combustion gas discharge conduit means of said plurality of piston chambers to open and close said air supply and combustion gas discharge conduit means;

said multi-port slide valve member having a companion set of inlet and outlet ports for each said piston chamber disposed therein for flow of gaseous fluids therethrough during reciprocation of said multi-port slide valve member;

an air-preheating manifold heat exchanger disposed adjacent said engine block and communicating with corresponding said air supply conduit means and corresponding said combustion gas discharge conduit means of each said piston chamber;

said manifold heat exchanger having air inlet and outlet means, combustion gas inlet and outlet means, and separate fluid passageways therewithin for flow of hot combustion gases and cooler combustion air therethrough; and

a fluid pump, disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of said manifold heat exchanger;

said method comprising the steps of;

transforming rotary motion of the output crankshaft of said engine to reciprocating motion of said multi-port slide valve member in transmission means which communicates between said crankshaft and said multi-port slide valve member;

.

synchronizing the reciprocation of said multi-port slide valve member with rotation of said crankshaft, so that said multi-port slide valve member continuously completes each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

transferring heat between hot combustion gases discharged from said plurality of piston chambers and incoming combustion air supplied from the discharge of said fluid pump through heat transfer surfaces of said manifold heat exchanger, and preheating combustion air supplied to said plurality of piston chambers of said engine;

sequentially flowing a charge of pressurized preheated combustion air into each said piston chamber from said air outlet means of said manifold heat exchanger through its conduit air supply means by way of a corresponding said inlet port of said reciprocating multi-port slide valve member, while discharging spent combustion gases from the piston chamber into said gas inlet means of said manifold heat exchanger by way of its said combustion gas discharge conduit means and its said companion outlet port of said reciprocating multi-port slide valve member;

impelling the discharge of spent combustion gases from each said piston chamber while its corresponding said piston is near its bottom dead-center cyclic position, by admitting pressurized preheated combustion air into the piston chamber which displaces and expels spent combustion gases therefrom;

stopping the flow of pressurized preheated combustion air into each said piston chamber and the discharge of gaseous fluids therefrom during the compression stroke of its corresponding said piston, when the said reciprocating multi-port slide valve member cyclically closes the said conduit air supply means and said combustion gas discharge conduit means serving the said piston chamber;

injecting a dispersed liquid fuel into each said piston chamber, during the compression stroke of its corresponding said piston, and

igniting the compressed air-fuel mixture within each said piston chamber by an electric spark, as its corresponding said piston is near its top dead-center cyclic position.

52. The method of claim 51 wherein each said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its said piston chamber during its compression stroke, said engine having no spark ignition means, with the additional steps of:

compressing the combustion air charge supplied into each said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into each said piston chamber during the compression stroke of its corresponding said piston; and

spontaneously igniting the compressed air-fuel mixture within each said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.

53. A method for operating a reciprocating multi-cylinder internal combustion engine having an engine block housing a plurality of piston chambers;

each said piston chamber closed by a cylinder head at its high-pressure end and having a reciprocating piston slideably disposed therein to compress and expand gaseous fluids;

conduit means for intermittently supplying combustion air into each said piston chamber from opposite sides thereof;

means for intermittently supplying a combustible fuel into each said piston chamber;

means for intermittently igniting a compressed air-fuel mixture within each said piston chamber;

conduit means for intermittently discharging spent combustion gases from opposite sides of each said piston chamber;

a linked pair of reciprocating multi-port slide valve members slideably disposed on opposite sides of said plurality of piston chambers in guideway means of said engine block across said conduit air supply means and said combustion gas discharge conduit means of each said piston chamber to open and close said air supply and combustion gas discharge conduit means;

each said multi-port slide valve member having a companion set of inlet and outlet ports for each said piston chamber disposed therein for flow of gaseous fluids therethrough during reciprocation of said linked pair of reciprocating multi-port slide valve members;

a pair of air-preheating manifold heat exchangers disposed on opposite sides of said engine block and communicating with corresponding said air supply conduit means and corresponding said combustion gas discharge conduit means on opposite sides of each member of said plurality of piston chambers;

each said manifold heat exchanger having air inlet and outlet means,, combustion gas inlet and outlet means, and separate fluid passageways confining flow of hot combustion gases and cooler combustion air therethrough and a fluid pump disposed to supply pressurized combustion air through communicating conduit means into said air inlet means of each said manifold heat exchanger;

comprising the steps of;

transforming rotary motion of the output crankshaft of said engine to reciprocating motion of said linked pair of multi-port slide valve members in transmission means which communicates between said crankshaft and means linking said multi-port slide valve members;

synchronizing the reciprocation of said multi-port slide valve members with rotation of said crankshaft, so that said pair of multi-port slide valve members continuously completes each reciprocating cycle in conjunction with completion of a designed rotation of said crankshaft;

transferring heat between hot combustion gases discharged from said plurality of piston chambers and incoming combustion air supplied from the discharge of said fluid pump through heat transfer surfaces of said oppositely-disposed manifold heat exchangers, and preheating combustion air supplied to said plurality of piston chambers of said engine;

sequentially flowing a charge of pressurized preheated combustion air into each said piston chamber from opposite sides thereof and from said air outlet means of said oppositely-disposed manifold heat exchangers through its corresponding said air supply conduit means by way of corresponding said inlet ports of said linked pair of reciprocating multi-port slide valve members, while discharging spent combustion gases from the piston chamber into said gas inlet means of said opposite manifold heat exchangers by way of its corresponding said combustion gas discharge conduit means and corresponding, said companion outlet ports of said linked pair of reciprocating multi-port slide valve members.

impelling the discharge of spent combustion gases from each said piston chamber from opposite sides thereof while its corresponding said piston is near its bottom dead-center cyclic position, by admitting pressurized preheated combustion air into the piston chamber from opposite sides thereof which displaces and expels spent combustion gases therefrom;

stopping the flow of pressurized preheated combustion air into each said piston chamber and the discharge of gaseous fluids therefrom during the compression stroke of its corresponding said piston, when the said linked pair of reciprocating multi-port slide valve members cyclically closes said conduit air supply means and said combustion gas discharge means serving the said piston chamber;

injecting a dispersed liquid fuel into each said piston chamber during the compression stroke of its corresponding said piston, and

igniting the compressed air-fuel mixture within each said piston chamber by an electric spark, as its corresponding said piston is near its top dead-center cyclic position.

54. The method of claim 53 wherein each said piston closely approaches said cylinder head at its top dead-center cyclic position to substantially reduce the volume of its said piston chamber during its compression stroke, said engine having no spark ignition means, with the additional steps of:

compressing the combustion air charge supplied into each said piston chamber until the air temperature substantially exceeds the ignition temperature of a liquid fuel;

injecting the liquid fuel as a dispersed aerosol into each said piston chamber during the compression stroke of its corresponding said piston; and

spontaneously igniting the compressed air-fuel mixture within each said piston chamber, as the dispersed liquid fuel aerosol contacts the heated combustion air charge therewithin.