Abstract: A method for controlling an exhaust gas purification system that can effectively implement desulfation of a selective catalytic reduction (SCR) device. The method for controlling an exhaust gas purification system, in which a diesel particulate filter (DPF) and an SCR device are combined, may include calculating a sulfur poisoning amount of the SCR device and an amount of soot loading in the DPF; and increasing a temperature of the SCR device to a desulfation temperature when the sulfur poisoning amount is greater than a first predetermined value and the amount of soot loading is less than a second predetermined value.

Abstract: An engine exhaust system includes an exhaust pipe assembly having an engine exhaust system inlet configured to receive engine exhaust and an engine exhaust system outlet. The system includes a first selective catalytic reduction (SCR) catalyst device positioned downstream in exhaust flow from the engine exhaust system inlet. The first SCR catalyst device includes a substrate with a metallic catalyst coated on the substrate. An electric heater is configured to heat the metallic catalyst. A second SCR catalyst device is positioned downstream in engine exhaust flow from the first SCR catalyst device and upstream of the engine exhaust system outlet. The first SCR catalyst device and the exhaust pipe assembly define an empty chamber between the substrate and the second SCR catalyst device. Engine exhaust flows directly from the substrate to the second SCR catalyst device through the empty chamber.

Abstract: An assembly unit 1 of an exhaust system has at least one and particularly two connection funnels 2 made of cast material and a pipe 3. The at least one connection funnel 2 has a pipe socket 21 and at least one bracket 22. The bracket 22 is arranged outside of the pipe socket 21. A connection section 31 of the pipe 3 is fastened to the bracket 22 of the at least one connection funnel. The pipe socket 21 extends beyond the connection section 31 of the pipe 3 into the interior of the pipe 3 and is spaced apart from an inner wall of the pipe 3 by at least the simple wall thickness of the pipe 3.

Abstract: A muffler is disclosed. The muffler may comprise an expansion chamber and a double shell housing surrounding the expansion chamber and extending from a first end to a second end. The double shell housing may include an annular perforated inner shell, an annular outer shell surrounding the inner shell, and an insulation between the inner shell and the outer shell. The muffler may further comprise at least one C-bracket between the inner shell and the outer shell at each of the first and second ends of the double shell housing. Each of the C-brackets may include a first leg, a second leg, and a linking portion connecting the first leg and the second leg. The second leg may be in abutting engagement with the outer shell.

Abstract: A dual chamber coolant reservoir having a single vent neck. The coolant reservoir is for an internal combustion engine cooling system wherein the reservoir housing includes a first chamber and a second chamber formed integral thereto. A vent neck includes an aperture for accessing the first chamber with either a two or three o-ring cap to maintain pressure within the first chamber. Means for venting the second chamber when coolant exceeds a predetermined pressure level and a means for venting the first and second chamber when said cap is moved from a closed position to an open position. An inline pressure relief valve and check valve providing pressure relief and air displacement.

Abstract: A heat exchanger includes first, second, third, and fourth passages. Engine coolant flows through the first passages. Engine oil flows through the second passages. Transmission oil flows through the fourth passages after flows through the third passages. Each first passage and each third passage is disposed in the same layer. Each second passage and each fourth passage is disposed in the same layer. Each first and each third passage are disposed in a different layer from the layer of each second and each fourths flow passage. Each fourth passage is disposed upstream of a first flow direction of the engine coolant in each first passage, and each second passage is disposed downstream of the first flow direction. Each third passage is disposed upstream of a second flow direction of the engine oil in each second passage, and each first passage is disposed downstream of the second flow direction.

Abstract: Methods and systems are provided for a phase change material (PCM) integrated radiator. In one example, a method may include adjusting a radiator control valve into a first position to flow coolant only through a first zone of a radiator containing phase change material (PCM) and not through a second zone of the radiator not containing phase change material. The method may further include adjusting the radiator control valve into a second position to flow coolant only through the second zone of the radiator and not the first zone.

Abstract: An internal combustion engine (10) comprising: a piston (12) arranged to reciprocate within a cylinder (14); an adjustable volume induction chamber (50) communicating with the cylinder (14); an air inlet port (30) communicating (42) with the induction chamber (50), the air inlet port (30) being connectable, in use, to a pressurized air supply (38); an air inlet valve (32) configured to selectively open and close the air inlet port (30); and a fuel injector (70) communicating with the induction chamber (50), wherein the valve (32) and fuel injector (70) are together configured, in use, to deliver a charge comprising a fuel-air mixture into the induction chamber (50).

Abstract: An assembly for controlling air flow to an engine includes a first supercharger (20) and a second supercharger (22). The superchargers are arranged in parallel with one another and in series with the throttle (70) in the air flow to the engine cylinders, and are configured to be operatively connectable with the engine upstream in the air flow to the cylinders. The assembly includes a load device (38) selectively connectable to the first supercharger (20) and selectively alternately operable to provide energy to or receive energy from the first supercharger. The superchargers are configured to be separately selectively operatively connectable with the throttle and the crankshaft to enable different modes of operation.

Abstract: A method of operating a supercharger (10) for an automotive engine (20) is disclosed. A supercharger (10) has an input shaft (30) for coupling to a crank shaft (22) of the engine and also for coupling to the rotor of a first electrical machine (40) and the annulus of an epicyclic gear train (60). An output shaft (70) is connected to a compressor (80) and a sun gear of the epicyclic gear train (60). A carrier carrying planet gears of the epicyclic gear train (60) is connected to the rotor of a second electrical machine (50). The first electrical machine (40) is selectively operable to supply electrical energy to the second electrical machine (50). The second electrical machine (50) is selectively operable as a motor or a generator to accelerate or decelerate the compressor (80), thereby tending to increase or decrease the power output of the engine.

Abstract: An exhaust-gas turbocharger includes a turbine housing and a wastegate which is disposed in the turbine housing. The turbine housing is water-cooled. An electric wastegate actuator is an integrated constituent part of the turbine housing.

Abstract: An exhaust turbocharger has a wastegate valve and a thrust circulation valve, which can be actuated by a single, common actuator. The actuation of the thrust circulation valve is dependent on the positioning velocity of the actuator.

Abstract: An exhaust-gas turbocharger (1) having a compressor (2) which has a compressor housing (3); having a turbine (4) which has a turbine housing (5); and having a charge-pressure regulating device (6). The charge-pressure regulating device (6) has at least two flap arrangements (7, 8) and two bypass duct openings (9, 10) assigned to the flap arrangements (7, 8).

Abstract: An actuating device for a valve of an exhaust-gas turbocharger may include a lever arm and a flap plate connected to one another for closing and opening the valve. The flap plate may have a concave recess, and the lever arm may have a spherical region configured in a complimentary manner to the concave recess of the flap plate. A holding device may be disposed on the flap plate and engage around the spherical region of the lever arm to secure the flap plate on the lever arm. The holding device may include at least two holding elements and a connecting element that connects the at least two holding elements.

Abstract: A valve device of a turbocharger includes: a valve seat disposed on an entrance of a fluid passage divided into at least two branches, and an opening/closing valve coupled to a rotary shaft rotatably disposed adjacent to the valve seat. The valve seat has a contact surface which is flat and a dividing section which extends across the entrance and divides the entrance into two entrance sections. The opening/closing valve closes the entrance of the fluid passage disposed in the valve seat. The bottom surface of the opening/closing valve is in surface contact with the contact surface of the valve seat. The central portion of the opening/closing valve corresponding to the dividing section is spaced apart from the dividing section at a predetermined distance.

Abstract: A method of introducing additives to an air intake system of an engine in order to overcome one or more of the various problems created by formulation of additives in fuels. The method controls at least one of the amount, aerosol particle size and timing of introduction of additives based on information relevant to operation of the engine. The introduced additives form an air-additive mixture and are carried by the airflow in the air-intake system to the combustion chamber of the engine. Another aspect of the invention is an additive introduction system that includes one or more containers for additives, a control system for determining at least one of the amount, aerosol particle size and timing of introduction of the additives, and a device to introduce the additives into the air intake system under the control of the control system.

Abstract: A compound cycle engine having an output shaft, at least two rotary units each including an internal combustion engine with the rotor of each rotary unit mounted on the output shaft and in driving engagement therewith, and a turbine including a rotor in driving engagement with the output shaft. The exhaust port of each rotary unit housing is in fluid communication with the flowpath of the turbine upstream of its rotor. The turbine is disposed co-axially between two of the rotary units. The engine may further include a compressor in fluid communication with the inlet port of each housing and a second turbine having an inlet in fluid communication with the flowpath of the first turbine downstream of its rotor. A method of compounding rotary engines is also discussed.

Abstract: A variable compression ratio apparatus may include a plunger configured to move up and down in response to rotation of a crank shaft, a piston having a chamber formed thereinside, into which the plunger is inserted, and configured to move up and down with the plunger, the chamber including an upper chamber formed above the plunger and a lower chamber formed below the plunger, a spool valve configured to selectively supply oil to the upper chamber or to the lower chamber, and a controller configured to control the spool valve so that the piston moves up and down with respect to the plunger.

Abstract: A wave disc engine apparatus is provided. A further aspect employs a constricted nozzle in a wave rotor channel. A further aspect provides a sharp bend between an inlet and an outlet in a fluid pathway of a wave rotor, with the bend being spaced away from a peripheral edge of the wave rotor. A radial wave rotor for generating electricity in an automotive vehicle is disclosed in yet another aspect.

Abstract: The invention relates to a method for operating a gas turbine, in which an oxygen-reduced gas and fresh air are delivered to a compressor of the gas turbine in a radially staged manner, the fresh air being delivered via an outer sector of the inlet cross section in relation to the axis of rotation of the compressor, and the oxygen-reduced gas being delivered via an inner sector of the inlet cross section in relation to the axis of rotation of the compressor. The invention relates, further, to a gas turbine power plant with a gas turbine having a compressor inlet which is followed by the flow duct of the compressor and which is divided into an inner sector and an outer sector, a feed for an oxygen-reduced gas being connected to the inner sector of the compressor inlet, and a fresh air feed being connected to the outer sector of the compressor inlet.

Abstract: A gas turbine engine comprises a main compressor section having a high pressure compressor with a downstream discharge, and more upstream locations. A turbine section has a high pressure turbine. A tap taps air from at least one of the more upstream locations in the compressor section, passes the tapped air through a heat exchanger and then to a cooling compressor. The cooling compressor compresses air downstream of the heat exchanger, and delivers air into the high pressure turbine. The cooling compressor includes a downstream connection that delivers discharge pressure air to an upstream location in the high pressure turbine and a second tap from an intermediate pressure location within the cooling compressor. The second tap is connected to a downstream location within the high pressure turbine. An intercooling system for a gas turbine engine is also disclosed.

Abstract: In one featured embodiment, a nozzle for a valve comprises a nozzle body surrounding a center axis and defined by an overall length extending from an inlet end to an outlet end. The nozzle body has a nozzle bore defined by an outlet bore inner diameter at the outlet end and an inlet bore inner diameter at the inlet end. The inlet bore inner diameter is greater than the outlet bore inner diameter, and the nozzle body has a nozzle face defined at the outlet end. The nozzle face is defined between the outlet bore inner diameter and an outlet bore outer diameter spaced radially outwardly of the outlet bore inner diameter. A ratio of the outlet bore inner bore diameter to the outlet bore outer diameter at the nozzle face is between 0.95 and 0.98.

Abstract: The gas turbine system has: a gas turbine having a compressor, a combustor, and a turbine; a fuel supply mechanism for supplying fuel to the combustor; a composition detection unit for detecting the composition of the fuel; and a controller for controlling the flow rate of the fuel supplied from the fuel supply mechanism to the combustor, on the basis of a function of the exhaust temperature of exhaust gas passing through the turbine and either air pressure of air expelled from the compressor to the combustor or an expansion ratio of the turbine. The controller calculates the specific heat ratio of the combustion gas from the composition of the fuel detected by the composition detection unit, corrects the function on the basis of the calculated specific heat ratio, and controls the flow rate of the fuel on the basis of the corrected function.

Abstract: Various embodiments include a system having: at least one computing device configured to tune a set of gas turbines (GTs) by performing actions including: commanding each GT in the set of GTs to a base load level, based upon a measured ambient condition for each GT; commanding each GT in the set of GTs to adjust a respective power output to match a scaled power output value equal to a fraction of a difference between the respective power output and a nominal power output value, and subsequently measuring an actual emissions value for each GT; and adjusting an operating condition of each GT in the set of GTs based upon a difference between the respective measured actual emissions value, a nominal emissions value at the ambient condition and a nominal emissions value at the ambient condition.

Abstract: Various embodiments include a system having: at least one computing device configured to tune a set of gas turbines (GTs) by performing actions including: modelling each GT in the set of GTs at a base load level, based upon a measured ambient condition for each GT; commanding each GT in the set of GTs to adjust a respective power output to match a scaled power output value equal to a fraction of a difference between the respective power output and a nominal power output value, and measuring an actual emissions value for each GT during the adjusting of the respective power output; and adjusting an operating condition of each GT in the set of GTs based upon a difference between the respective measured actual emissions value, a nominal emissions value at the ambient condition and a nominal emissions value at the ambient condition.

Abstract: A control device for an internal combustion engine includes an in-cylinder pressure detector, an output shaft torque calculator, a target torque calculator, an input torque parameter calculator, and a controller. The output shaft torque calculator is to calculate an output shaft torque of an output shaft of the internal combustion engine based on an in-cylinder pressure. The target torque calculator is to calculate a target torque of the output shaft torque. The input torque parameter calculator is to calculate an input torque parameter representing an input torque such that the output shaft torque becomes equal to the target torque using a feedback control algorithm which is based on a controlled object model which models a controlled object that receives the input torque parameter as input and produces the output shaft torque as output. The controller is to control the output shaft torque using the input torque parameter.

Abstract: Methods and systems are provided for reducing blackening of an oxygen sensor due to voltage excursions into an over-potential region. Before transitioning the sensor from a lower voltage to an upper voltage during variable voltage operation, an operating temperature of the sensor is reduced via adjustments to a sensor heater setting. The reduction in temperature increases the range of temperatures available to the sensor before the over-potential region is entered.

Abstract: An ignition control device having an Electronic Fuel Injection mode and a Capacitive Discharge ignition mode is described. The ignition control device comprises: an output for providing an output voltage, connected or connectable to a load, the load being a fuel injection actuator of an EFI system or an ignition capacitor of a CDI system; and a driver unit connected to the output, for driving the output voltage from a low level to a high level and from the high level to the low level in dependence on an input signal, each transition of the output voltage from the low level to the high level having a low-to-high transition time which is longer for the CDI mode than for the EFI mode.

Abstract: The invention relates to a control device of a vehicle provided with a multi-cylinder internal combustion engine comprising a catalyst in an exhaust passage. When a state of an ignition switch has been changed from an on-state to an off-state and a rotation of the engine has stopped, the control device causes a fuel injector to inject fuel into a combustion chamber of a particular cylinder in which an intake valve is closed and an exhaust valve is open and causes an ignition device to ignite the fuel.

Abstract: There is provided a controller, for a supercharger-equipped internal combustion engine, that can accurately estimate a supercharging pressure, without providing a pressure sensor for detecting the supercharging pressure. In a controller for a supercharger-equipped internal combustion engine, a correction value for correcting a supercharging pressure estimation value is changed so that an effective opening area estimation value, estimated based on a supercharging pressure estimation value and the like, approaches a preliminarily set effective opening area default value corresponding to a throttle opening degree detection value.

Abstract: A natural gas engine system may have an engine having at least one cylinder. The engine may also have an intake manifold configured to deliver air for combustion to the cylinder and an exhaust manifold configured to discharge exhaust from the cylinder. The natural gas engine system may have a generator coupled to the engine. The generator may be configured to generate electrical power for an electrical load. The natural gas engine system may have a fuel source configured to supply natural gas for combustion in the engine, and an air tank in fluid communication with the intake manifold and the exhaust manifold. Further, the natural gas engine system may have a controller. The controller may be configured to direct a first amount of air from the air tank to the exhaust manifold and a second amount of air from the air tank to the intake manifold.

Abstract: A method is provided, comprising indicating a fuel vapor canister load based on a steady-state fuel vapor circulation rate in a vapor recovery line during a refueling event; and adjusting a canister purging operation in response to the indicated fuel vapor canister load. Restrictions in the vapor recovery line may increase the rate of fuel vapor canister loading during a refueling event. In this way, an accurate canister load may be determined following a refueling event, and canister purging operations adjusted accordingly.

Abstract: A method is provided, comprising indicating a fuel vapor canister load based on a steady-state fuel vapor circulation rate in a vapor recovery line during a refueling event; and adjusting a canister purging operation in response to the indicated fuel vapor canister load. Restrictions in the vapor recovery line may increase the rate of fuel vapor canister loading during a refueling event. In this way, an accurate canister load may be determined following a refueling event, and canister purging operations adjusted accordingly.

Abstract: An internal combustion engine has a plurality of cylinders and is provided with an arrangement for exhaust gas recirculation. The plurality of cylinders is divided into a first group and a second group of cylinders. The internal combustion engine further has a control device arranged to provide a heating mode of the internal combustion engine where the first group cylinders are deactivated and the second group cylinders are activated. The control device is arranged to provide a higher proportion recirculated exhaust gas than inlet air to the first group cylinders in the heating mode.

Abstract: A control apparatus includes an electronic control unit configured to: carry out a first diagnosis and a second diagnosis; control a first injection valve and a second injection valve such that fuel is injected from both the first injection valve and the second injection valve, and such that a fuel injection amount from the second injection valve is not reduced and a fuel injection amount from the first injection valve is reduced, when carrying out the first diagnosis; and control the first injection valve such that fuel is not injected from the first injection valve, and control the second injection valve such that the fuel injection amount from the second injection valve is reduced in a state where fuel is injected from the second injection valve, when carrying out the second diagnosis.

Abstract: Various systems and methods are described for controlling fuel injection in a variable displacement engine. One method for a deactivatable cylinder comprises, before deactivating the cylinder responsive to operating conditions, disabling a port injector and fueling the cylinder only via the direct injector. The method further comprises, when reactivating the cylinder from deactivation, enabling both the port injector and the direct injector, and injecting a higher amount of fuel via the direct injector while simultaneously injecting a lower amount of fuel via the port injector.

Abstract: In an internal combustion engine, an exhaust purification catalyst and a hydrocarbon feed valve are arranged in an exhaust passage. When a temperature of the exhaust purification catalyst falls in a first catalyst temperature region (I), a first NOX purification method is performed, while when a temperature of the exhaust purification catalyst falls in a second catalyst temperature region (II), a second NOX purification method is performed. When the temperature of the exhaust purification catalyst falls in a region (IIP) in the second catalyst temperature region close to the first catalyst temperature region, the temperature of the exhaust purification catalyst is made to increase to shift the region in which the temperature of the exhaust purification catalyst falls to the first catalyst temperature region to thereby switch the NOX purification method used from the second NOX purification method to the first NOX purification method.

Abstract: A fuel cut during deceleration is executed at time point t1. An oxygen storage amount (rOS) which increases with this fuel cut is estimated based on an exhaust air-fuel ratio and an intake air quantity. When the oxygen storage amount (rOS) reaches a threshold value (at time point t2), a target compression ratio (tCR) is corrected to become lower than a basic target compression ratio (tCR). Although a fuel recovery is executed at time point t4, a combustion temperature is lowered because of the lowering of the mechanical compression ratio, so that a production of NOx in a combustion chamber is suppressed. Therefore, worsening of NOx is suppressed even if the oxygen storage amount (rOS) of exhaust-emission purification catalyst (4) is excessive.

Abstract: The internal combustion engine comprises a supercharger, a variable valve timing mechanism able to change a valve overlap amount, a catalyst arranged in an exhaust passage and able to store oxygen, a downstream side air-fuel ratio sensor arranged at a downstream side of the catalyst in an exhaust flow direction and able to detect an air-fuel ratio of outflowing exhaust gas flowing out from the catalyst, and a scavenging control device able to control a scavenging amount by controlling the valve overlap amount by the variable valve timing mechanism. The scavenging control device reduces the valve overlap amount when an air-fuel ratio detected by the downstream side air-fuel ratio sensor changes from less than a lean judged air-fuel ratio leaner than a stoichiometric air-fuel ratio to the lean judged air-fuel ratio or more during scavenging.

Abstract: A method for recognizing the type of fuel actually used in an internal combustion engine; the recognition method includes the steps of: sensing the intensity of the vibrations generated by the internal combustion engine within a measurement time window; determining the value of at least one synthetic index by processing the intensity of the vibrations generated by the internal combustion engine within the measurement time window; comparing the synthetic index with at least one predetermined comparison quantity; and recognizing the type of fuel actually used as a function of the comparison of the synthetic index to the comparison quantity; and forcedly altering, when detecting the intensity of the vibrations, the engine control with respect to the normal standard engine control, so as to enhance the behavioral differences of the different types of fuel that can be used by the internal combustion engine.

Abstract: A method for determining the opening for piezo servo-driven injectors may include measuring a voltage and a charge at an end of a charging process of the piezo actuator; determining a provisional scaling factor by calculating Q/U; determining the maximum of CVORL and using the instant at which the maximum occurs as an approximation value of the valve opening instant; measuring the charge and voltage at the approximation of the valve opening instant; solving the equation: 1.25×F2/E×C=(U×C?Q)2 Where F=force acting on the piezo actuator, E=electrical parameter of the piezo actuator; determining a new scaling factor from the solution of the equation; calculating the difference (U×C?Q) and determining a maximum of said value; and using the instant at which said maximum occurs as valve opening instant.

Abstract: A system for detecting a leakage/failure in in an intake line of an internal combustion engine comprising an intake line (IL) and an exhaust line (EL), means (HFM) for measuring or for estimating a quantity of fresh air ({dot over (m)}HFM) entering said intake line (IL), means for measuring or for estimating a quantity of fuel ({dot over (m)}FUEL) injected in the engine (E), measurement or estimation means (? and/or NOx), on the exhaust line, adapted to provide a first value (?measured) of an air/fuel ratio introduced in the internal combustion engine (E), the system comprising processing means (ECU) adapted to calculate a second value (?exp) of said air/fuel ratio, calculated on the basis of the measured and estimated quantities of fresh air ({dot over (m)}HFM) and fuel ({dot over (m)}FUEL) to calculate an error (?err) between the first and the second value (?measured??exp) and to detect a condition of leakage/failure if said error is outside a predefined interval [?err?, ?err+] containing the value zero.

Abstract: An engine control method of a hybrid vehicle for controlling the engine depending on an engine load of the hybrid vehicle includes: learning a change amount of an engine load; determining at least one engine torque depending on a magnitude of the engine load; calculating an optimum torque value by using the learned change amount of the engine load and at least one determined engine torque; and controlling the engine by using the calculated optimum torque value.

Abstract: When the temperature in a cylinder of an engine is low, the fuel injection amount of fuel that has a low vapor pressure and is less likely to be vaporized is increased, and the fuel injection amount of fuel that has a high vapor pressure and is more likely to be vaporized is reduced, so that the start timing of the engine can be kept constant. When the temperature in the cylinder is high, the fuel injection amount of the fuel that has a low vapor pressure and is more likely to be decomposed is reduced, and the fuel that has a high vapor pressure and is less likely to be burned (decomposed) is increased, so that the start timing of the engine can be kept constant. Thus, the start timing of the engine is kept constant irrespective of the fuel property, and deterioration of the drivability can be curbed.

Abstract: A cylinder for a V-twin engine including a body with a first end having a surface configured to mate with a cylinder head, and a second end configured to mate with a crankcase. A sleeve is fixedly secured within the body to define a cylinder bore. The sleeve includes a first portion that extends from the first end of the body to the second end of the body. The first portion of the sleeve has a first wall thickness. The sleeve further includes a second portion that extends out of the second end of the body to be received within a crankcase bore. The second portion has a second wall thickness that is thinner than the first wall thickness. The sleeve is constructed from a chromoly steel alloy material, and the second wall thickness is less than 0.060 inch.

Abstract: An engine block assembly and method manufacturing an engine block assembly and related components. A casted engine block assembly includes a cylinder block portion. The cylinder block portion includes a plurality of cylinder block openings disposed therein, a cylinder block flange portion positioned at a top of the cylinder block portion and a cylinder block crankcase portion disposed at a base of the cylinder block. The cylinder block flange portion is configured for coupling the cylinder block to a cylinder head. The cylinder block portion includes a plurality of cylinder block walls extending between the cylinder block flange portion and the cylinder block crankcase portion and positioned about the plurality of cylinder block openings. The cylinder block walls house a plurality of internal channels. The plurality of cylinder block walls are void of enclosed openings extending through at least one of the cylinder block walls in the plurality of cylinder block walls.

Abstract: A two-stroke internal combustion engine includes at least one gaseous communication charge passage between a crankcase chamber and a combustion chamber of the engine and a piston to open and close the top end of the transfer passage. The air inlet port to the transfer passage for stratified scavenging is opened and closed by the piston that has passages and cutouts. The charge inlet to the crankcase chamber is opened and closed by the piston. The air inlet passage is substantially asymmetrical to the layout of the transfer passages and are closer to one transfer passage compared to the other. The internal air passage in the piston is substantially parallel to the piston pin and the single air inlet passage is laterally off-set from the air-fuel inlet passage. The transfer passages are cover by plates to make them closed passages having opening at the transfer port in the cylinder and opening in the crankcase chamber for periodical gaseous communication between the crankcase chamber and the combustion chamber.

Abstract: Exemplary piston assemblies and methods of making the same are disclosed. An exemplary piston assembly may include a piston crown and a piston skirt that is received in a central opening of the crown. The piston crown may include a ring belt portion defining, at least in part, a cooling gallery. The crown and skirt may each further include corresponding mating surfaces that extend about a periphery of the crown and skirt. The skirt mating surface and crown mating surface may generally be secured to each other that the crown and the skirt cooperate to form a continuous upper combustion bowl surface. The skirt and crown may cooperate to define a radially outer gap about a periphery of the piston crown.

Abstract: The present disclosure provides an open-faced piston with a circumferential groove into which a piston ring assembly is arranged. Openings at the bottom of the circumferential groove and between a front land of the open-faced piston and the piston face are provided. The openings are arranged to allow for a combustion reaction to propagate through the volume defined between the bottom of the piston ring assembly and the piston face such that at least a portion of an air and fuel mixture located in that volume is reacted.

Abstract: A small air-cooled internal combustion engine includes an aluminum cylinder block, an aluminum cylinder head welded to the aluminum cylinder block, and a weld securing the aluminum cylinder block to the aluminum cylinder head, wherein a joint having a first length is formed between the aluminum cylinder block and the aluminum cylinder head and wherein the weld extends for a second length that is at least 25% of the first length.