# Generation III Internal Engine - pushrod length calculations?

View Full Version : pushrod length calculations?

scj
04-28-2012, 12:37 AM
i know i will still need do an on motor test with a pushrod length checker, but i kinda want to get a general idea of what i'm looking at as far as length goes for the pushrods.

i'm running trick flow as cast 220cc heads for an ls2. they recommend an average of .100" longer pushrod than the factory 7.4" so approximately a 7.5" length pushrod on an unmilled head. they come stock with a 65cc combustion chamber, but i had them milled to 60cc's, so as far as milling goes thats about .050" milled off. The motor is a forged 370, and has a custom spec'd camshaft. I'm also running the thunder racing shim kit inorder to use stock rockers which is .090" of shimmed height on the rocker stands. the motor has a cometic .040" compressed thickness headgasket, so that means it's approx. .011" thinner than a stock headgasket. so tell me if my general math is what should be close to the actual pushrod length?

+7.4" (stock pushrod lengt)
+.100" (TFS's recommendation)
+.090" (shim kit from TR)
= 7.529" approximated..

i know this is very rough, i just want to make sure i'm looking at this correctly based on the vauge information i'm given without actually taking a pushrod length checker to the motor itself. i just want to make sure that i get around this number calculated when i do my measuring with a length checker on the motor it self.

01ssreda4
04-28-2012, 01:11 AM
I'd set the checker at your spec and go from there on your measurement.

ZeeOSix
04-28-2012, 04:23 AM
= 7.529" approximated..

i know this is very rough, i just want to make sure i'm looking at this correctly based on the vauge information i'm given without actually taking a pushrod length checker to the motor itself. i just want to make sure that i get around this number calculated when i do my measuring with a length checker on the motor it self.

Set your pushrod checker to 7.400 and go from there. You can calculate all you want, but the only thing it might do is save you the trouble of making a few more turns on the tool when it's installed in the motor for the real measurement. :)

Darkman
04-28-2012, 09:53 AM
http://ls1tech.com/forums/13879292-post9.html