Diesel engines modified to be fuelled with gaseous fuels experience problems with knocking and pre-ignition, limiting the compression ratio and efficiency of the engine. A new combustion chamber for a gaseous fuelled internal combustion engine, in which the combustion chamber is defined by a cylinder head, a bore in a cylinder block and a piston reciprocating in the bore, comprises a piston portion of the combustion chamber defined by a recessed shape in a piston crown; and a head portion of the combustion chamber defined by a recessed surface in the cylinder head. A ratio between the piston portion of combustion chamber volume and the head portion of combustion chamber volume is in a range of 0.7 to 1.3.

An engine-driven electricity generation system can selectively use diesel and LNG as fuel by recycling a diesel engine from a scrapped vehicle and heats intake air with an electric heater to start an engine using LNG and then heats the intake air using heat from a high-temperature exhaust gas after starting the engine, thereby accelerating ignition of LNG.

An engine-driven electricity generation system can selectively use diesel and LNG as fuel by recycling a diesel engine from a scrapped vehicle and heats intake air with an electric heater to start an engine using LNG and then heats the intake air using heat from a high-temperature exhaust gas after starting the engine, thereby accelerating ignition of LNG.

An engine-driven electricity generation system can selectively use diesel and LNG as fuel by recycling a diesel engine from a scrapped vehicle and heats intake air with an electric heater to start an engine using LNG and then heats the intake air using heat from a high-temperature exhaust gas after starting the engine, thereby accelerating ignition of LNG.

A generator system includes (i) an internal combustion engine, (ii) an exhaust gas outlet, connected to the internal combustion engine, for venting exhaust gasses, and (iii) a condenser, connected to the exhaust gas outlet, for condensing water from exhaust gasses.

A method for preventing a piston oil-up, may include determining an oil-up condition formation to use a controller, wherein an oil-up oil generates since an engine oil moves upward above a piston, after an engine operation state is verified; determining a suction condition of the oil-up oil to use the controller based on any of a cylinder total control suction method, a cylinder explosion sequence suction method and a cylinder identical stroke sequence suction method when the oil-up condition has been formed; and operating an oil pump to use the controller, sucking the oil-up oil to use a suction force of the oil pump and discharging the sucked oil-up oil from a cylinder block.

A method of converting a diesel engine to a natural gas engine comprising inserting a spark plug into a diesel fuel injector opening in a cylinder head; installing a throttle body on the diesel engine; installing a throttle body adaptor between a throttle body and an intake manifold of said diesel engine; and modifying a piston, whereby the compression ratio of said piston is decreased during operation of said piston. The method also includes installation of a waste gate and waste gate adaptor and a timing mask.

A method of converting a diesel engine to a natural gas engine comprising inserting a spark plug into a diesel fuel injector opening in a cylinder head; installing a throttle body on the diesel engine; installing a throttle body adaptor between a throttle body and an intake manifold of said diesel engine; and modifying a piston, whereby the compression ratio of said piston is decreased during operation of said piston. The method also includes installation of a waste gate and waste gate adaptor and a timing mask.

A portable generator includes an engine including an air-fuel mixing device, an alternator, first and second fuel reservoir fluidly coupled to the air-fuel mixing device, a first fuel valve and a second fuel valve movable to an open position that allows fuel to flow from respective fuel reservoirs to the air-fuel mixing device and a closed position that prevents fuel from flowing from respective fuel reservoirs to the air-fuel mixing device, a fuel selector input device operable to select the first or second fuel reservoir as the source of fuel, and a controller programmed to automatically open or close the first fuel valve and open or close the second fuel valve in response to an input from the fuel selector input device indicating selection of the first or second fuel reservoirs.

One of the processes needed for the conversion of a diesel engine so that it can use natural gas as fuel is the reduction of the compression ratio, since the one that the diesel engine originally has is greater than the one needed for the optimal operation with natural gas.

The proposed process consists of adding cold material to the cylinder head or engine head through metallization or electric arc or plasma spraying to form a combustion chamber therein.