If you look at the list below showing the popular 4 cylinder Honda car engines, out of the 9 series represented, only one of the nine has a stroke rod ratio over 1.62, and that one is 1.74, well less than the 1.84 of the factory CB750 ratio.
The other 8 series engines were between 1.52 and 1.62.
George
George, what is the "redline" on those Honda car engines? My 2001 Civic has a redline at 6800 RPM. With a short rod, more power may be produced in a lower RPM range, but less power at higher revs due to increased piston/cylinder friction.
Scottly,
That’s a good question and a good point. Performance minded modern Honda auto engines seem to have a decline between 7000-8300 depending on the model. Those that further modify them report low to mid 9000s is not uncommon on street/street racer based engines.
The performances built sohc4 engines are typically peaking under 10,500rpm. Some are higher of course. So yes, certainly not and apples to apples comparison.
Don,
Sure, that type of work could probably be done. Machining down the right side rotor snout would be an easier task than creating and rotor snout on the left side, but sure it’s possible. Not sure if it’s worth the risk hanging a rotor on a welded snout😬
Either way, there is quite a bit of effort necessary to make a dohc crank work in a Sohc race engine, but the results are proven over the many examples that have raced. It’s a bit more work to make it work for a street engine that requires electric start and a functional charging system. All doable, just extra work.
George