Our proprietary system involves a two-prong approach to the effective reduction of harmful exhaust emissions from conventional diesel engines. The first prong of the approach involves the strategic redesign of both the exhaust cam profile of the conventional uniflow-scavenged two-stroke diesel engine component and of the cylinder liner CCTS Kitconfiguration thereof in a manner to cause an increase in the volume of residual exhaust gases that remain in the cylinder during the compression, combustion and powerstrokes. This increase in the volume of the residual exhaust gases within the cylinder leads to an increase in compression temperature and effectively increases the compression ratio and consequently the compression pressure. Because of the heat absorption capacity of these residual exhaust gases, the exhaust gases remaining in the cylinder, following the scavenge stroke, tend to absorb combustion heat and thereby effectively reduce the peak combustion temperature. This reduction in peak combustion temperature advantageously results in the lower than normal production of nitrogen oxide (NOx) and, therefore, allows advancement of the injection timing, while still maintaining the NOx emissions coming from the engine lower than those legislatively mandated. Advantageously, the advance in injection timing, which increases NOx emissions will, in accordance with the well understood NOx versus particulate matter tradeoffs, also have the effect of reducing particulate matter emissions. Thus, by increasing the volume of residual exhaust gases within the cylinder, significant particulate matter emission reductions can be achieved, while at the same time maintaining NOx emissions well below acceptable levels.

The second prong of the inventive approach involves modification of the turbocharger component of the system in a manner to provide additional oxygen to the combustion process. The provision of additional oxygen to the heated CCTScombustion chamber of the engine accelerates the oxidation of the soluble organic fraction contained within the chamber which is a major component of the undesirable particulate matter emissions. More specifically, the additional charge of oxygen-rich air into the combustion chamber effectively increases the compression pressure, which in turn, leads to an earlier start of combustion because of the combustible mixture reaching its auto ignition temperature at an earlier point in time. This phenomenon leads to more thorough combustion of the fuel and also generally leads to higher exhaust temperatures. Higher exhaust temperatures, in turn, lead to a greater oxidation rate of the soluble organic fraction thus further lowering the level of undesirable particulate matter emission from the engine.

With the foregoing discussion in mind, it is an object of the present system to provide a mechanical power plant and the method of making the same for use both in on-road and off-road applications, in which the exhaust emissions from the modified diesel engine component of the system is substantially reduced.

Another object of the system is to provide a mechanical power plant of the aforementioned character which includes a specially modified, conventional two-stroke uniflow-scavenged diesel engine that has a lower than normal exhaust valve lift and a shorter than normal exhaust valve open time, thereby effectively increasing the amount of residual exhaust gases remaining in the combustion chamber following the scavenge stroke.

Another object of the system is to provide a mechanical power plant as described in the preceding paragraphs which provides for a greater than normal flow of oxygen-rich air into the combustion chamber of the modified diesel engine so as to accomplish more complete and efficient combustion of fuel and, at the same time, accelerate the oxidation of the soluble organic fraction, that is the unburned lubricating oil and fuel fraction formed in the exhaust system and trapped on the particulate emission sampling filter.

Another object of the system is to provide a unique mechanical power plant in which the nitrogen oxide emissions exhausted from the diesel engine component are effectively maintained at levels below those set by the air quality regulatory agencies.