Abstract: A supplemental fuel regulator for diesel engines, and a system for adding supplemental fuel to diesel engines is provided. The fuel regulator has two chambers, one which receives fuel from the fuel tank through a fuel inlet valve, which also reduces the pressure of the fuel. The fuel at much reduced pressure is passed to a second chamber through a fuel control valve. Fuel is drawn from the second chamber into an outlet duct, directly into the airflow duct of the diesel engine. A vacuum line from the engine pulls fuel from the second chamber. As engine demand increases, the engine vacuum increases, and additional fuel is supplied by the regulator. A solenoid switch provides control over the system, which can be activated by a user when the supplemental fuel system is deemed desirable. The solenoid switch can be configured to shut off the supplemental fuel system whenever the diesel engine is shut off.

Abstract: A fuel injection system with a common rail pressure reservoir which is filled with fuel at high pressure, and a dual substance nozzle for dual-fluid injection of fuel and a supplementary liquid into an internal combustion engine. The system includes a 2/2-way valve in the injection line between the common rail pressure reservoir and a pressure chamber surrounding the nozzle needle of the dual substance nozzle. A pressure fluid container with supplementary liquid under pressure, which via a storage valve can charge the supplementary liquid line with a respective predeterminable quantity of supplementary liquid and that in turn can be charged with supplementary liquid by means of a pump via a check valve and its internal pressure can be kept at a desired level by a pressure regulating valve. As a result, the otherwise usual, technologically substantially more complex 3/2-way magnet control valves can be replaced by a single, less expensive 2/2-way valve.

Abstract: A fuel control system for delivering gaseous fuel from a source through an air/fuel mixture to a gas-operated engine that includes at least one sensor for operative coupling to the engine to provide at least one electronic sensor signal responsive to engine operating conditions. An electronic control unit is responsive to the sensor signal(s) for providing a fuel control signal indicative of a desired quantity of fuel to be delivered to the engine. A pressure regulator, for disposition between the fuel source and the fuel/air mixture, is responsive to the fuel control signal for controlling delivery of gaseous fuel to the mixer. The pressure regulator includes a housing having an inlet for connection to the fuel source and an outlet for connection to the mixer. A valve is disposed within the housing and biased toward closure by a primary pressure regulating spring for controlling flow of fuel from the inlet to the outlet.

Abstract: The invention relates to an alternate fuel system for a diesel engine that contains a fuel processing unit, and a alternate fuel storage tank that feeds alternate fuel to the fuel processing unit and then on to the engine. In this case, there are a series of pressure control valves that control the pressure and flow of the alternate fuel from the storage vessel to the fuel processing unit. In addition, to ensure safe operation of the fuel processing unit it has a relief valve that releases excess pressure from the system. Furthermore, this fuel processing unit has a heater to vaporize the alternate fuel for feedings into the system. This alternate fuel system will feed the alternate fuel from the fuel lines in either a fixed fuel flow or a variable fuel flow system.

Abstract: A method for transitioning between a first operating mode of a dual fuel engine and a second operating mode of the dual fuel engine includes establishing a final liquid fuel amount desired to be delivered to the engine upon completion of the transition to the second operating mode. Delivery of liquid fuel to the engine is adjusted by a first amount and, correspondingly, delivery of gaseous fuel to the engine is adjusted by a second amount, where an energy content of the first amount of liquid fuel is substantially the same as an energy content of the second amount of gaseous fuel. A determination is made as to whether liquid fuel is being delivered to the engine in an amount which is substantially the same as the desired final liquid amount previously established.

Abstract: A method of operating an engine assembly having a cylinder assembly which defines a combustion chamber is disclosed. The cylinder assembly includes an engine block having a piston cylinder defined therein, a piston which translates in the piston cylinder, and a crankshaft which is mechanically coupled to the piston. The method includes the steps of performing an intake stroke of the engine assembly and advancing gaseous fuel and air into the combustion chamber during the intake stroke performing step. The method further includes the step of performing a compression stroke of the engine assembly after the is intake stroke performing step. The method yet further includes the step of injecting a pilot fuel into the combustion chamber during the compression stroke while the crankshaft is positioned at about X degrees before top dead center, wherein 21.0<X<28.0.

Abstract: An internal combustion engine of the Diesel type has an injection system with injectors which at high pressure injects compressed liquid gas into the combustion chambers of the cylinders. The liquid gas may be produced from volatile organic compounds evaporated from crude oil tanks. The engine can be a high-compression engine with a compression ration of at least 1:14, and the liquid gas can have a methane number of less than 10.

Abstract: In one embodiment of the present invention an apparatus for controlling one or more engines by synchronizing the functions of two or more electronic control modules includes a master electronic control module, one or more slave electronic control modules, and one or more data links for transferring data between the electronic control modules. Engine control and monitoring functions are divided between the master electronic control module and the slave electronic control modules. The present invention may be used to control and monitor dual fuel engines and engines that operate on one type of fuel. The master electronic control module may transition operation of the engine to the diesel fuel only mode in the event of a failure of any dual fuel mode specific components. The master ECM coordinates timing and speed of fuel injection to engine cylinders using input from an adjustable engine speed command device and a speed sensor connected to each engine.

Abstract: A method of detecting leakage through a gaseous fuel admission valve of a dual fuel engine including at least one such gaseous fuel admission valve and a gaseous fuel shut off valve includes determining a liquid fuel rate when the engine is operating in a liquid fuel mode and the gaseous fuel shut off valve is closed. The gaseous fuel shut off valve is thereafter opened while the engine is operating in the liquid fuel mode. A liquid fuel rate is determined after the gaseous fuel shut off valve is opened and the liquid fuel rate determined before opening of the gaseous fuel shut off valve is compared with the liquid fuel rate determined after opening of the gaseous fuel shut off valve. A detonation level within the engine cylinder may also be checked to determine if such detonation level exceeds a predetermined level indicative of gaseous fuel leakage. The detonation level check may also be utilized in a spark-ignited engine.

Abstract: A method of operating an engine assembly having a cylinder assembly which defines a combustion chamber is disclosed. The method includes the steps of performing an intake stroke of the cylinder assembly and advancing a conditioning fuel into the combustion chamber during the intake stroke performing step. The method further includes the steps of advancing a gaseous fuel into the combustion chamber during the intake stroke performing step and performing a compression stroke of the cylinder assembly after the intake stroke performing step. The method yet further includes the steps of advancing a pilot fuel into the combustion chamber during the compression stroke performing step and combusting the pilot fuel in the combustion chamber during the compression stroke performing step so as to ignite the conditioning fuel and the gaseous fuel.

Abstract: A control box (11) for a dual-fuel internal-combustion engine (6) is actuated automatically by an oil-pressure switch (16) when activated by a manual switch (30) that directs power from a battery (29) or other engine-electrical component to a current distributor such as a 24-volt bus (49) for operating control-box components that include an under-current sensor (36) for preventing use of gaseous fuel in addition to liquid fuel under no-load and low-load conditions, an over-current sensor (39) for preventing use of gaseous fuel in addition to liquid fuel under excessive-load conditions, an intake-air sensor (17) for preventing use of gaseous fuel with liquid fuel when there is inadequate supply of air, a liquid-fuel-supply sensor (22) for preventing use of gaseous fuel with liquid fuel when there is inadequate supply of liquid fuel, and an exhaust-gas-temperature monitor (23) for shutting down dual-fuel mode when exhaust heat is excessive. Red LED lights (41, 42, 43, 44, 45, 46) warn of system faults.

Abstract: This invention relates to a novel hydraulically actuated fuel injector for an internal combustion engine. More particularly, the application pertains to a hydraulically actuated gaseous injector for injecting main fuel and optional pilot fuel into an internal combustion engine at different times at controlled pressure. A hydraulically actuated fuel injector for a piston displacement engine comprising: (a) an injector which is actuated by an actuator means and injects fuel into the engine at predetermined times; (b) a means for introducing hydraulic oil into said injector; (c) means for pressurizing said hydraulic oil; (d) means for opening a fuel inlet means and injecting the fuel into the engine upon the pressure of the hydraulic oil reaching a predetermined level; and (e) a means for preventing the pressure of the hydraulic oil from rising above the predetermined level.

Abstract: A method for adjusting a fuel control system of an engine capable of operating in both a first mode during which only a first fuel is delivered to the engine and a second mode during which both the first fuel and a second fuel are delivered to the engine includes operating the engine in the first mode during which a governor output value (X.sub.M1) is established and stored in memory. The engine is then operated in the second mode during which a governor output value (X.sub.M2) is established. The governor output value (X.sub.M2) is compared with the stored governor output value (X.sub.M1) and a stored second fuel energy content value is adjusted based upon the comparison. The actual energy content of the second fuel can also be directly calculated.

Abstract: A combustion process is described, suitable for use in piston internal combustion engines, wherein two separate mixtures are used, one fuel leaner and one fuel richer than the minimum ignition delay mixture ratio. When the richer mixture is injected into the leaner mixture, interdiffusion creates zones readily compression ignitable. Burning is thusly initiated, which subsequently completes the combustion of the combined air fuel mixture. Very fuel lean overall mixture ratios can be utilized in this way to reduce undesirable exhaust emissions and to increase engine efficiency.

Abstract: A method for delivering liquid fuel and gaseous fuel to a dual fuel engine operating in a dual fuel mode includes establishing a governor output value indicative of a total fuel energy rate desired to be delivered to the engine to maintain a desired engine speed. A first value indicative of a liquid pilot fuel energy rate desired to be delivered to the engine and a second value indicative of a gaseous fuel energy rate desired to be delivered to the engine are each determined such that the sum of the desired liquid pilot fuel energy rate and the desired gaseous fuel energy rate is substantially equal to the desired total fuel energy. A stored gaseous fuel energy content can be updated to assure continued accuracy of the fuel control system of the dual fuel engine.

Abstract: A standard diesel injection system and a mechanical direct-gas injection system are selectively operable, in combination with a continuous pilot injection system, to provide a combustion system that is capable of operating in either a conventional diesel mode or a dual-fuel mode. Operation between convention diesel or dual-fuel combustion modes is mechanically controlled by a two-position, four-way control valve. The mechanical direct-gas injection system is actuated by pulsed diesel fuel directed to the actuation chamber of a gas injector by the same injection pump used to provide diesel fuel to the combustion chamber during conventional diesel operation.

Abstract: A gas engine with electronically controlled and/or regulated injection of relatively small quantities of injection oil in such a way as to improve the metering accuracy of the injection oil quantity, the flexibility with which the required ignition oil quantity is provided and the ability to freely preset the timing of ignition oil injection. The engine comprises a separate electronically controllable injection system for each cylinder including at least one ignition oil injection device 13 connected via an injection line 14 to a separate ignition oil hydraulic pump 16 which is in fluid communication with a pressure accumulator 15. An electronically controllable switching device 19 associated with the injection device 13 is electronically connected to an engine control device 20 that controls, regulates and monitors the ignition oil injection.

Abstract: An engine assembly includes a plenum member having an inlet opening and an outlet opening defined therein. The engine assembly further includes an air source in fluid communication with the inlet opening. The engine assembly still further includes a fuel combustion assembly having an engine block having a piston cylinder defined therein, an engine head secured to the engine block and having an intake port defined therein, and a piston which translates within the piston cylinder. The piston, the piston cylinder, and the engine head cooperate so as to define a combustion chamber. The engine assembly further includes a gaseous fuel supply valve which controls the amount of gaseous fuel advanced from a gaseous fuel source to the first intake conduit. The engine assembly still further includes an intake conduit interposed between the outlet opening and the intake port.

Abstract: A method of operating a computer to automatically produce production control software for a natural gas engine controller (104) on a machine is provided. The controller (104) is adapted to control a natural gas engine (106). The method includes the steps of (1) as a function of user input, defining a set of controller (104); and (2) producing control software to operate the controller (104) as defined by the specifications.

Abstract: A parametric emissions monitoring system for monitoring stationary engine/compressor units coupled to a pipeline provides, in a reciprocating embodiment, reliable and accurate determinations of emission levels for NO.sub.x, CO, and total hydrocarbons (THC) from an emissions matrix primarily as a function of engine speed and engine torque. Validation of the determined emissions level is provided by comparing the values of a set of actual engine operating parameters with a respective value in a set of calculated engine operating parameters to determine whether the deviation of the actual operating parameter from the expected operating parameter is within a defined range, and thus whether the engine is operating within a defined control envelope. Each set of engine operating parameters includes spark ignition timing, fuel rate, and air manifold pressure.

Abstract: A control system for and exhaust retarder in and exhaust pipe of an engine to which a mixer and throttle valve are connected including terminating means for terminating fuel feed into the engine upon receipt of an exhaust retarder shutter operation signal, an oxygen richness sensor on the exhaust pipe and a control system for operating an actuator for the exhaust retarder shutter when sensed oxygen density in the exhaust pipe deviates from a predetermined oxygen range.

Abstract: To provide an injection system for an internal combustion engine operating on self-igniting liquefied gas as a fuel, and to minimize cavitation and related problems of fuel delivery as well as wear, the fuel tank is configured as a low-pressure storage tank which is connected to a pressure control unit maintaining a constant interior pressure at a level above that of the vapor pressure of the liquefied gas, preferably at 6 to 30 bar, approximately, and further the injection system is configured as a leakage-free system.

Abstract: An internal combustion engine is provided with a methane feed system including a plurality of methane injection devices respectively associated with the various cylinders of the engine. The methane injection devices are mounted within respective seats communicating with a distributing conduit or rail for feeding methane. The seats for the injection devices in the rail are formed in an auxiliary body separate from the intake manifold and the head of the engine. An electronic control unit provides for the control of the injection devices on the basis of signals indicative of the parameters of operation of the engine so as to carry out the methane injection at each cylinder when the rotational speed of the engine is lower than a predetermined threshold when the intake valve of the cylinder is open.

Abstract: In a gas combustion engine, which is manufactured by conversion of a diesel engine, the piston shape, the compression ratio, the air intake system and the exhaust gas system are modified. The exhaust gas system is split into two parts, each of which consists of an exhaust branch-piece and a catalyser, whereby catalysers of standard format can be employed, and the air intake system is made smaller, whereby the probability of backfire is reduced. The hollow in the piston already present in the diesel engine is enlarged in diameter and depth, in such a manner that the ratio of the diameter to the depth is equal to 30:11. In this manner, one achieves an optimal form with respect to heat extraction. In addition, enlargement of the hollow causes a lowering of the compression ratio to a value of 1:10, which is necessary when applying gas as a fuel.

Abstract: A compression ignition engine can be quickly and easily converted into a dual fuel engine simply by adding a gaseous fuel supply system, by disconnecting the governor actuating lever from the throttle pedal, and by adding an electronic controller which controls the operation of the gaseous fuel supply system and which sets the governor actuating lever at a position which causes the engine to deliver pilot fuel at a desired quantity. Operation is simplified by setting the governor using a droop control technique inherent in governor operation. The system can be automatically calibrated to assure the supply of fuel at a precisely controlled quantity per stroke at all engine speeds. The pilot fuel injection system of the resulting engine is non-invasive and permits inherent safety features of the governor to be retained.

Abstract: A method and apparatus for increasing fuel economy of a diesel fuel engine in which an aerator (40) bubbles air through diesel fuel (F) in a diesel fuel tank (T) to generate diesel fuel fumes in the ullage (U). In a turbocharged diesel engine, the fumes are directed by a valve (60) to fume injectors 86 and injected just before the turbo charger fan (32). In a normally aspirated engine, the fumes are directed by a valve (160) to the intake manifold (124).

Abstract: A combustion engine (1) of the piston engine type where the static compression ratio exceeds approximately 15:1, especially in the range of from approximately 15:1 to approximately 20:1, preferably approximately 17:1. The engine is provided with an ignition system (3) where the ignition point is situated after the top dead center (TDC), especially in the range of from approxmiately 0.degree. TDC to approximately 20.degree. TDC, preferably approximately 4.degree. TDC. As a result, it is possible to achieve an ignition of a fuel, the spontaneous ignition capacity of which at the predetermined compression ratio does not usually suffize. The resulting ignition generates a maximum pressure in the cylinder of approximately 90.degree. TDC, whereby a high efficiency of the fuel is obtained without simultaneously involving a steep increase in the temperature in the combustion chamber.

Abstract: A method for maintaining the pressure of a compressible fuel resident in a reservoir above a predetermined minimum including withdrawing compressed air from an internal combustion engine's combustion chamber, further compressing that withdrawn air, transmitting that further compressed air to an expandable air compartment which, with a fuel compartment having an outlet, occupies the interior of a reservoir. Apparatus for maintaining the pressure of a compressible fuel above a predetermined minimum including a reservoir having an air compartment and a fuel compartment separated by a moveable barrier, an internal combustion engine having a combustion chamber, means for transmitting air from the combustion chamber to the air compartment, a compressor for compressing the transmitted air, and a valve for obstructing air transmission when the fuel compartment's pressure exceeds a predetermined maximum.

Abstract: A fuel injection system for an engine having a cylinder, a piston in the cylinder, and an inlet port at the cylinder comprising a fuel inlet passage communicating with the inlet port and adapted to be connected to a fuel source and a fuel valve movable between an open position for allowing fuel to flow in the inlet passage and a closed position preventing fuel flow. The fuel valve is biased into one of the open or closed positions and a control system permits movement of the fuel valve to the open position at timed intervals to deliver metered volumes of fuel to the engine cylinder.

Abstract: Liquefied petroleum gas (propane), natural gas, hydrogen gas, or the like, is continuously injected at substantially constant pressure into the air intake manifold, or air induction system, of a conventional internal combustion engine, the engine being electronically, or mechanically, controlled to adjust the air to liquid fuel mixture to a optimum value. The engine may use liquid gasoline, methanol, diesel, or any other, primary fuel. When retrofitted to a conventional 2 or 4 stroke, spark or compression ignited engine, the gaseous fuel preferable is supplied from a reservoir where it is stored in liquefied or compressed form through an appropriate pressure control valve to a pipe T installed in the crankcase ventilation pipe. The supply of gaseous fuel is controlled by an ON-OFF solenoid valves which are only operated when the alternator or generator of the engine is running and the engine has attained a predetermined temperature.

Abstract: A dual fuel injection arrangement for an internal combustion engine. Fuel is injected into the inlet manifold ducts to each engine cylinder via injectors. An arrangement of valves allows selected supply of either a first fuel or a second fuel to the injectors via inlet fuel rail and branch lines. Excess fuel is returned to each supply by way of return line (11). Electronic control units determine injection timing for the selected fuel dependent upon engine parameters for the first fuel and upon an adjusted timing for the second fuel where the adjustment takes account of the different characteristics of the second fuel compared with the first fuel. In particular there is disclosed an arrangement where the first fuel is gasoline and the second fuel is a liquified gas.

Abstract: A dual fuel control system (10) for use with an internal combustion engine (11) is disclosed which controls the flow of liquid fuel alone or in combination with a gaseous fuel. The system has a stored supply of gaseous fuel and a fuel metering actuator (22) which regulates the flow of the gaseous fuel to the engine. The system also has a stored supply of liquid fuel and a fuel control actuator (47) which regulates the flow of diesel fuel through the movement of the shutoff valve (31) of a diesel fuel pump (28). A controller (45) controls the actuation of the actuators in response to signals received from an accelerator sensor (37), an R.P.M. sensor (45) and an exhaust temperature sensor (41).

Abstract: A supplemental gaseous fuel system is provided for retrofit to an existing diesel engine having a conventional load sensitive speed control. The supplemental gaseous fuel system operates independently of the load sensitive speed control thus enabling the diesel fuel supply system to rapidly react to load transients. A control system senses a physical position of an actuator mechanism in the diesel fuel injector pump and opens and closes a buffer valve in response to predetermined positions of the actuator. In normal operation of the engine, variations (increases) in engine load are initially corrected for by an immediate but momentary increase in diesel fuel to the engine. However, as soon as the engine has responded to the increase in diesel fuel and increased its rate of combustion, the gas flow to the engine is increased and causes the diesel fuel actuator to approach a minimum fuel setting.

Abstract: A method for converting a diesel engine to a natural gas fueled engine, the method comprising the steps of providing new cam profiles on a cam shaft portion of the diesel engine, the new cam profiles being operative to close intake valves of cylinder heads of the engine during intake strokes, operative to close exhaust valves of the cylinder heads, and operative no earlier than the exhaust valves closures to open associated intake valves, modifying portions of the cylinder heads to adapt the cylinder heads to accept spark plugs, fixing spark plugs in the cylinder heads, providing means for conveying natural gas fuel to the intake valves, providing a blower for supplying air under pressure to the intake valves, and providing an after-cooler for cooling the air supplied by the blower prior to the air reaching the intake valves.

Abstract: This invention relates to a novel device for compressing and injecting gaseous fuel from a variable pressure gaseous fuel supply into a fuel receiving apparatus. More particularly, this invention relates to an intensifier-injector which compresses and injects gaseous fuel from a variable pressure source into the cylinder of a positive displacement engine. An intensifier-injector for gaseous fuels in internal combustion engines comprising means which utilizes the compressed gas from the chamber of the internal combustion engine or compressed fluid or gas from an external compressor to drive an intensifier means which raises the pressure of fuel gas supplied to the internal combustion engine for rapid late-cycle injection into the cylinder of the internal combustion engine.

Abstract: This invention relates to a gas engine, in particular a four-cycle gas engine, having a mixture line (7) to the combustion spaces in the cylinders (2) and having a mixer (5) in the mixture line (7), in which air is mixed into the fuel gas, and a metering valve (8) for the metering of the gas delivery, the metering valve (8) being actuated by a controller (4) for the control of the pollutant emission, and the controller (4) adjusting the metering valve (8) in dependence on the power setting of the gas engine (1) and an engine parameter measuring the pollutant emission.

Abstract: A fuel injection method for diesel internal combustion engines uses main injection of a gas main fuel and pilot injection of a liquid secondary fuel to initialize combustion of the main fuel. The liquid fuel is injected by an injector pump designed to enable the engine to achieve its maximum power with the liquid fuel only. The pilot injection comprises a mixture of water and liquid fuel.

Abstract: A dual fuel system for a diesel engine includes a liquid (diesel) fuel injection system controlled by an engine electronic control unit (ECU) and a source of gaseous fuel such as natural gas. A metering valve and a mixer controls introduction of gaseous fuel from the natural gas fuel source into combustion air for the engine. An electronic governor controls the metering valve and a link controller coordinates operation of the ECU and the governor. Preferably, a regulator regulates the natural gas pressure supplied to the metering valve. A shut-off valve controls communication of natural gas between the source and the regulator. The link controller also controls the shut-off valve as a function of sensed conditions.

Abstract: A system for fueling a compression ignition engine that minimizes the quantity of ignition fuel required by controlling the quantity of combustible mixture, rather than the fuel to air ratio.

Abstract: A fuel comprising natural gas modified by the addition of hydrogen in appropriate proportions to produce a mixture with a burn rate that matches the burn rate of the gasoline is provided for burning in a gasoline engine without the need for modifications in engine timing, combustion chamber geometry, or other engine design parameters. A mixture of natural gas and nitrogen is also used to increase the knock limit on the power curve of fumigated diesel (compression ignition) engines and to increase the lean burn limit in spark ignition engines.

Abstract: A fuel injection structure for dual fueled combustion engines having access to the combustion chamber of a cylinder to automatically supplement a liquid fuel with a gaseous fuel, the structure being adapted to supply the gaseous fuel by a programmed electronic control circuit which regulates the operation of fuel injection to be in accord with certain sensed engine operation parameters to determine from said parameters a desired gaseous fuel flow rate and a signal responsive to said parameters actuating a valve to control said flow.

Abstract: A fuel supplying system of a gas-engine is comprised of a gas-engine, an intake manifold, a mixer communicated with the gas-engine via the intake manifold, a fuel passage, a gas tank communicated with the mixer via the fuel passage, an air passage, an air cleaner communicated with the mixer via the air passage, and a governor inserted in the fuel passage. The governor is comprised of a first gas room, a second gas room, an opening between the first gas room and the second gas room, and an atmospheric pressure room defined in the second gas room by a first diaphragm. The opening between the first gas room and the second gas room is open and closed by a valve. A lever is fixed to the valve and a first spring urges the valve to close the opening. An apparatus is supplied for varying the urging force of the spring.

Abstract: A system is described that extends the driving range provided in prior art by compressed gas fuel systems and that thereby reduces the need for bi-fuel operating capability in most applications. The system can typically more than double the energy density of a compressed gas fuel storage system. The system includes apparatus for metering the fuel supplied to the engine to minimize noxious emissions.

Abstract: An alternative fuel system that operates in conjunction with the primary fuel system to utilize the output from the existing or original equipment manufacturer's control module from the primary system, modifies that signal and controls a fuel supply valve for the alternative fuel so that the proper quantity of alternative fuel is supplied to the engine.

Abstract: An improved combustion process for an internal combustion engine including cylinders provided with inlet and outlet valves as well as inlet and outlet ducts. During a suction stroke with the outlet valve closed, fuel is fed into the cylinder through separate feeding valve means for providing a lean fuel/air mixture in the cylinder; during a compression stroke a first additional charge of fuel is fed into the cylinder by use of a considerable over pressure for igniting the lean fuel/air mixture and after ignition of the fuel/air mixture a second additional charge of fuel is fed into the cylinder for increasing the effective mean pressure of the engine. The second additional charge of fuel comprises a substantial part, and for achieving maximum mean effective pressures the main part, of the fuel fed into the cylinder during a working cycle of the process.

Abstract: A dual fuel, natural gas/diesel two-stroke engine includes a cylinder and a piston in the cylinder, and inlet ports around the cylinder which are uncovered by downward movement of the piston. A blower forces air through the inlet ports when the latter is uncovered, and the engine includes an exhaust port and valve for exhausting combustion gases once each cycle. Diesel injection takes place near top dead center to ignite the gaseous mixture. An injector is provided for injecting natural gas into the cylinder once each cycle, including a delivery conduit which opens into the cylinder at a location above the inlet ports for air, such that the piston when descending completely uncovers the conduit before beginning to uncover the air inlet ports.

Abstract: A method of installing spark plugs in a diesel internal combustion engine during conversion of the engine to a spark ignited internal combustion engine using gaseous fuel works with an engine originally having a cylinder block, a cylinder head cooperable with the cylinder block, a rocker box cooperable with the cylinder head and a diesel fuel injector for each cylinder of the cylinder block originally intended to inject diesel fuel into said cylinder. The method involves: removing each diesel fuel injector and replacing it with a spark plug adapter sleeve with a spark plug communicating with the cylinder from which the respective injector has been removed; fixing a plurality of extension sleeves to the rocker box, each extension sleeve being associated with one spark plug adapter sleeve; and providing a seal ring for sealing between the inner end of each extension sleeve and the outer end of the associated spark plug adapter sleeve when the rocker box is fixed on the cylinder head.

Abstract: A dual fuel engine system and method of operating the engine reduces emission rates of polutants. The dual fuel engine includes a fuel oil supply connected to the engine and a fuel gas supply connected to the engine. Means connected between the fuel oil supply and the engine inject low levels of diesel fuel into the engine. In particular, the injection of diesel fuel is limited to pilot injection quantities only. The exhaust emission of NOx is maintained at less than 1 GM/HP-HR, where natural gas is used as the primary fuel, and less than 0.5 GM/HP-HR where digester gas is used as the primary fuel.

Abstract: An improved gas feed system for a gas fired diesel engine is disclosed, in which boil-off gas evaporated from liquefied gas is fed to the diesel engine. The improvements reside in that between the diesel engine and a liquefied gas tank for storing a gaseous fuel is provided a liquefied gas adding apparatus for adding liquefied gas into the boil-off gas, and in the provision of a passageway through which high-pressure gas passes pressurized by a high-pressure compressing apparatus which compresses the boil-off gas or a mixture of the boil-off gas and the liquefied gas and the provision of a passageway through which low-pressure gas passes pressurized by a low-pressure compressing apparatus.

Abstract: An important for a diesel engine by injecting LP gas into the diesel engine. A solenoid valve and a pressure controller are provided in a line between an LP gas cylinder and a gas injector mounted on the air inlet of the diesel engine. The solenoid valve is activated only when the engine temperature has risen above a predetermined level and only after the vehicle speed has exceeded a predermined level. This arrangement increases the output of the diesel engine, saves the fuel cost and eliminates black smoke.