If you are able to justify the fuel savings over say, 47 years, you may want to look into having a camshaft designed according to the Atkinson Cycle
Atkinson cycle - Wikipedia, the free encyclopedia
The Atkinson cycle may also refer to a four stroke piston engine in which the intake valve is held open longer than normal to allow a reverse flow of intake air into the intake manifold. This reduces the effective compression ratio and, when combined with an increased stroke and/or reduced combustion chamber volume, allows the expansion ratio to exceed the compression ratio while retaining a normal compression pressure. This is desirable for improved fuel economy because the compression ratio in a spark ignition engine is limited by the octane rating of the fuel used. A high expansion ratio delivers a longer power stroke, allowing more expansion of the combustion gases and reducing the amount of heat wasted in the exhaust. This makes for a more efficient engine.
|
This would sacrifice power output throughout the rpm range, perhaps below an acceptable threshold. A small turbo, coupled to a variable flow valve to increase gas velocity at low RPM would counteract any power losses entirely.
Mileage may vary.