I'm getting ready to build my first roller motor. last night I did the old "valve to piston clearance" check. My intake valve is about .190 from the piston on the intake side. The exhaust valve isn't even close. I'm running a comp 280H now that has .520 lift. I'm guessing I can go up to about .600 lift and still be within that .100 safety margin. What I'm wondering is if I go from my 1.72 roller tip rockers to a 1.70 full roller, how much lift will I lose by the decreased ratio, thus how much should I add in lift when picking the new cam to make up the difference?????

Thanks so much!!!

0.603" lift with a 1.70 rocker yields 0.10" clearance.


Larger Dave