how much do you gain with 202s over 188S?

christineman said
is it true that if you take a pair of J heads that are 188 intakes, that you dont dont gain much power if you punch them out to 202? do y ou pickup 12-20- HP by doing that??

christineman

the bowl shape off of the seat needs to be as good or matched as the 1.88's are to compare fairly.

the 2.02 from the factory flowed 20'ish cfm more than the 1.88.
I have tested this to know.

every 5 cfm is worth 10 hp according to most formulas like afr's.

what cubic inch?
what peak rpm?
what carb and cam?

this will make the diff in what to use.

and know that specific heads and their respective port shape will also dictate any increase from a larger valve.

ALSO the velocity gained from the smaller valve will be almost un noticable once you rev over/into the mid of the power band.

how sensitive is your arse dyno?