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In a conventional engine, the fresh fuel/air mixture is prepared
upstream of the cylinder (whether by carburetor or conventional
port fuel injection) and enters the cylinder during the intake stroke,
with the intent of forming a homogenous mixture of air and fuel
within the cylinder. The application of OCP technology enables
a highly stratified combustion process to occur, containing the
combustible fuel cloud to a small area within the cylinder, with
the remainder of the air in the cylinder not being fuelled.

This process at light loads allows engines
with OCP to run very lean (in some cases total engine operation
is carried out without the use of an air intake throttle). Under
high load conditions, the OCP system runs similar to a homogeneously
charged engine, with good mixing of the fuel/air mixtures within
the cylinder.
Key features of using OCP:
- Electronic control over the level of in-cylinder
fuel stratification
- Minimising short-circuiting on 2-stroke engines
- Allowing lean operation on 4-stroke engines
- Injected fuel is more effectively atomised
using low pressure air than liquid only injection systems which
require higher operating pressures
- Faster evaporation of fuel drops, cleaner burn
- Reduced engine parasitic losses
- The air provided during the injection event
contributes favourably to improving EGR tolerance
- Reducing NOx production
- Improving fuel economy
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