|
We know nothing of how that fe figure was arrived at.
If that first one has a side valve engine, they are not efficient with their low compression ratios and inefficient chamber designs.
That second one, being a Honda engine, could very well be OHV. In that case I'd think it could be about as efficient as an automotive engine. But both of them are geared way low (too low IMHO) and have more stuff in the drivetrain (torque converter, clutch, belt, chain, and another bearing on the trans input shaft) to decrease drivetrain efficiency vs stock.
And, if you actually work an engine too hard it falls off the top end of the best bsfc range, unlike the rest of us that suffer inefficiency from falling off the bottom end.
|