302 push rod size and adjustment after installing roller rockers, where do I start

tfry · 08-11-2008

I have installed 165 AFR heads with Scorpion pedestal roller rockers on my 302. I have 2 sets of push rods in two sizes; a set approx. 6-1/8" and a set approx. 6-7/8". The the short ones came with the heads and out of a 1993 roller motor. My motor is a flat lifter motor. Which size do I use and how do I adjust?
Tom

rattyoldtruck · 08-12-2008

try one of the cam tech sites. comp cams has a good one to help you. good luck!

rodbender · 08-12-2008

I wouldn't trust either until you measure what you need. There are several makers of pushrod measuring tools and instructions on the CORRECT way to do so.

silver69 · 08-13-2008

Follow Comp Cams site, if you do not do this right you will destroy the cam adn have to rebuild your engine to get all the metal out of it. I know the roller rods are way short. Find a local speed shop or call/visit summit racing (.com) for a push rod length checker.
Good luck

rodbender · 08-13-2008

I have to do this also for my motor. Went to Comp Cams website all good EXCEPT they don't tell you how to set up the geometry. I read where at 50% valve lift your roller tip should be at the center of the valve stem. I'm going to check some sites to see if that is correct and I'll get back with you on this. Regards

tfry · 08-15-2008

Thanks for the information. I did go to the Compcam site and a few others and I think I figured some of it out. The first thing is that the short rods are roller cam rods and they are way short. Next, I started with the shorter of the long rods and the intake was perfect but the exhaust was too long to the point that it compressed the valve(?) by a very slight amount. Went the the next cylinder and they did the same...too long. I quess that I will have to buy a measuring tool and start again. Thanks for all of your feed back.