A method is provided for adjusting timing of fuel injection into a combustion chamber of a compression-ignition engine. The method includes detecting a request for zero torque generation by the engine and cutting-off delivery of fuel into the combustion chamber during the detected zero torque request. The method additionally includes issuing a command to inject a test quantity of fuel into the combustion chamber during the detected request for zero torque generation. The method also includes assessing a timing delay between the command to inject the test quantity of fuel and a start of the test quantity injection, and determining a compensation for the assessed timing delay. The method additionally includes detecting a request for positive torque generation by the engine. The method further includes commanding a shift in the timing of fuel injection into the combustion chamber by the determined compensation during the engine's positive torque generation.

A method is provided for adjusting timing of fuel injection into a combustion chamber of a compression-ignition engine. The method includes detecting a request for zero torque generation by the engine and cutting-off delivery of fuel into the combustion chamber during the detected zero torque request. The method additionally includes issuing a command to inject a test quantity of fuel into the combustion chamber during the detected request for zero torque generation. The method also includes assessing a timing delay between the command to inject the test quantity of fuel and a start of the test quantity injection, and determining a compensation for the assessed timing delay. The method additionally includes detecting a request for positive torque generation by the engine. The method further includes commanding a shift in the timing of fuel injection into the combustion chamber by the determined compensation during the engine's positive torque generation.

A control device is provided for a compression ignition engine, which controls so that partial compression ignition combustion of A/F-lean mixture gas is carried out in a specific range where an engine load is low. In a first range of the specific range, a normal ignition in which sparks are generated in a late period of compression stroke or an early period of expansion stroke to start SI combustion, and a preceding ignition in which sparks are generated at a timing included in intake stroke or compression stroke and earlier than the normal ignition by a given amount or more are performed, and fuel is injected at a timing where fuel is present before the preceding ignition inside the combustion chamber. In a high-load side second range of the specific range, at least the normal ignition is performed and the execution of the preceding ignition is limited.

A control device is provided for a compression ignition engine, which controls so that partial compression ignition combustion of A/F-lean mixture gas is carried out in a specific range where an engine load is low. In a first range of the specific range, a normal ignition in which sparks are generated in a late period of compression stroke or an early period of expansion stroke to start SI combustion, and a preceding ignition in which sparks are generated at a timing included in intake stroke or compression stroke and earlier than the normal ignition by a given amount or more are performed, and fuel is injected at a timing where fuel is present before the preceding ignition inside the combustion chamber. In a high-load side second range of the specific range, at least the normal ignition is performed and the execution of the preceding ignition is limited.

A premixed compression ignition engine system includes an engine, a fuel injector, a water injector, and a controller. The controller conducts: a compression-stroke mid-period injection that causes a fuel injector to inject fuel to form a fuel-air mixture in a surrounding space of a combustion chamber; a compression top-dead-center injection that causes the fuel injector to inject fuel to form a fuel-air mixture in the central space of the combustion chamber after the compression-stroke mid-period injection; and a water injection that causes a water injector to inject water to the surrounding space of the combustion chamber at a timing from commencement of the compression-stroke mid-period injection to commencement of the compression top-dead-center injection.

A premixed compression ignition engine system includes an engine, a fuel injector, a water injector, and a controller. The controller conducts: a compression-stroke mid-period injection that causes a fuel injector to inject fuel to form a fuel-air mixture in a surrounding space of a combustion chamber; a compression top-dead-center injection that causes the fuel injector to inject fuel to form a fuel-air mixture in the central space of the combustion chamber after the compression-stroke mid-period injection; and a water injection that causes a water injector to inject water to the surrounding space of the combustion chamber at a timing from commencement of the compression-stroke mid-period injection to commencement of the compression top-dead-center injection.

A control device is provided for an engine in which premixed compression ignition combustion is carried out. The device includes an air amount adjusting mechanism, a variable valve mechanism, an exhaust choke valve, a water temperature sensor, and a processor. The processor controls the variable valve mechanism so that a valve overlap period of a given amount or more is formed in a low-load range where the engine load is low, and controls an injector, the air amount adjusting mechanism, and the exhaust choke valve so that A/F lean mixture gas is formed inside a combustion chamber, and premixed compression ignition combustion of the mixture gas is carried out. During the operation in the low-load range, the combustion controlling module makes an opening of the exhaust choke valve when a temperature parameter is low, smaller than that when the temperature parameter is high.

A control device is provided for an engine in which premixed compression ignition combustion is carried out. The device includes an air amount adjusting mechanism, a variable valve mechanism, an exhaust choke valve, a water temperature sensor, and a processor. The processor controls the variable valve mechanism so that a valve overlap period of a given amount or more is formed in a low-load range where the engine load is low, and controls an injector, the air amount adjusting mechanism, and the exhaust choke valve so that A/F lean mixture gas is formed inside a combustion chamber, and premixed compression ignition combustion of the mixture gas is carried out. During the operation in the low-load range, the combustion controlling module makes an opening of the exhaust choke valve when a temperature parameter is low, smaller than that when the temperature parameter is high.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.