I was going to stay out of this but...273 is 100% correct. Horsepower IS airflow and piston area and RPM. Horsepower is work across time. The same cylinder pressure on a longer stroke crank doesn’t make more horsepower. But the same cylinder pressure on a bigger bore makes more horsepower. Every time.
That’s why in CID/weight cars and classes with a maximum displacement rule (Pro Stock for example or ASScar when Chrysler got back into it could run a larger bore and shorter stroke and wax GM’s *** all day long so ASScar made a max bore rule of 4.185 for the GM garbage to compete...remember this was with a 358 CID rule...which means Chrysler used a bigger bore, shorter stroke and more RPM which is all more horsepower) you see the bores as big as you can get them and them adjust the stroke and rod ratio for RPM, induction, port cross section etc.
When I get home I’ll take a picture of the Bettes book where he clearly states this. Any cursory visit through a rule book or most any time on the dyno proves this out clearly.
That’s why even a 3.79 stroke is even a bit much for W2 heads, especially considering how much you give up in rod ratio (yes, it matters). A Stroker with a 4 inch arm (or longer) is vastly under headed, which is why you see inverted torque and horsepower numbers. So to get the horsepower number over the torque number you either have to cam the hell out of or reduce the stroke.
So...I said all that to say that stroke doesn’t increase horsepower. It can’t. Not with the same induction. When it counts, RPM is King. RPM is a horrible task master, but it’s still King. Ask Roy Johnson. He will tell you it is. He will also tell you that the RPM limit killed the Hemi in Pro Stock. The GM guys were 500 RPM or more behind, and they cried like babies to get the rule changed, claiming cost savings. It’s Pro Stock, not cheap assed Stock.
