Low pollution emissions of stratified-charge engines and fuel
economy of Diesel engines were incorporated into a
stratified-charge Diesel engine with direct fuel injection. Tests
and evaluation of this engine form the basis of the
investigation.
The paper is divided into two main parts. The first describes
particular components and parameters: combustion chamber, injection
jets, combustion air spin, timing, partial carburetion during
optional gasoline operation, and throttling of intake air. The
second part discusses these individual topics in light of the test
results. The following conclusions were reached:
- the spark-plug should be located close to the injection
jet
- exhaust emissions and fuel consumption depend on the direction
of the fuel injection spray
- The optimal fuel jet is a two-hole design derived from
one-hole models
- low combustion air spin yields poor performance
- within limits, timing of fuel injection and ignition may be
independently fixed; such timing can optimize fuel consumption and
nitric oxide emissions
- limited throttling of intake air can reduce pollutant
emissions with little reduction of performance
Optimal timing of such engines would entail considerable
expense.