So this one hit me as I was looking around wikipedia last night. I seem to recall reading somewhere a long time ago that the CRX HF engine ran on a different "cycle" than a normal engine, partially accounting for it's increased fuel efficiency.
A few minutes of searching turned up the
Otto cycle (the "normal" cycle) and the
Atkinson cycle (the high FE cycle).
It looks to me as if the only appreciable difference is in the lift duration of the intake cam. If it was possible to have a new cam ground to provide this increased intake duration, you could effectively convert your engine to the Atkinson cycle, thereby raising your FE.
So the question I'm posing for all of you engine gurus out there is this:
Would this be a feasible mod for all us folks out here with Otto cycle engines?