02anti_vnm

iTrader: (32)

Aite I finally! Got around to ordering my 225s they're on the way now but it just hit me today do I need longer pushrods? Since they have a 3/4 deck height they'll sit higher right? I'm running a comp hardened 7.4 standard length right now but will I need longer if so how much?

Thanks guys

jaber911

afr 62cc = 7.350 inch
afr 66cc = 7.400 inch
its mean ever 1 cc = 0.0125 inch
but !!
http://www.compcams.com/information/Products/Pushrods/

jr

02anti_vnm

iTrader: (32)

Kinda confuded the heads I bought are 72cc and I already have 7.4s so can I not use them?

jaber911

sure no
The length of pushrod depends on several things like cam , aftermarket heads
chamber cc, gaskit ,ets
bay Pushrod Length Checker

KRAZY K 2000 TA

iTrader: (5)

no no no all wrong 62cc and 66cc is just the chamber size has nothing to do with your pushrod length.

maybl8r09

iTrader: (1)

Buy a pushrod length checking tool. That is the only way to know for sure. As jaber911 said, there are many factors in getting the correct pushrod length, one size does not fit all .

COMP Cams 7702-1 - COMP Cams Hi-Tech Pushrod Length Checking Tools

Best of luck with it .

02anti_vnm

iTrader: (32)

Is there anyway to calculate a rough estimate cuz I'm already going to be pushing the dead line I really want to have it done by the f body meet in myrtle beach this year? If I can get it close to have it there I'd be more than happy to change them after

Specs are stock 2002 ls1 block, cometic .051 head gasket, afr 225s 72cc, a 224 224 .612 .609 116lsa 114icl the lifters are comp cams comp r lifters and stock 1.7 rockers

Maybe you can get me close I know what works on one car won't work on another but I just wana atleast get it close for the meet

Thanks guys

butler

my 7.4 worked fine on my 225's.

GTO1_OHIO

iTrader: (3)

I hope you're kidding.

KRAZY K 2000 TA

iTrader: (5)

well then what does combustion chamber size have to do with the pushrod length?

KRAZY K 2000 TA

iTrader: (5)

make sure you set the comp r lifters with the proper preload or failure will be possible,be tuff with stock rockers but possible.

02anti_vnm

iTrader: (32)

What cc are your heads and how thick are the head gaskets? Thanks

Ima check them when I get the heads on and if they aren't close I guess ima buy a pushrod checker and pay to overnight it and the pushrods when I figure out what I need

butler

That's what I have. 1/2 turn on preload. Motor spins to 7,000 at dragstrip. No problems.

02anti_vnm

iTrader: (32)

uuumm i might be lost on what you mean by preload?

johnster

iTrader: (27)

i am running afr 225 59cc stock gasket cam is 243/248 600 lift on a 110 stock rockers ls7 lifters and i am running 7.4 works great! i measured!!!

only way u r going to no 4 sure is to measure it

LS1x2

iTrader: (11)

So what pushrod did you end up with? I'll probably be running into this over the weekend. Thanks.

vettenuts

iTrader: (4)

Have you checked the Comp requirements for Comp R's? The recommended preload is 0.002"-0.004" and Comp recommends adjustable rockers. Seems you are in a rush to get this done and my suggestion would be to slow down and sort out what parts you have bought. I also personally wouldn't run stock rockers with AFR heads/bronze valve guides. I also wouldn't run stock rockers with Comp R's as getting the preload correct would be difficult at best, in a rush near impossible. Remember, the tolerance on pushrods is +/- 0.005", which is already outside the bounds of the Comp recommended preload of their lifter. You also need to check the rocker wipe on the AFR heads, which will change the pushrod length requirement. I needed to adjust the height of my rockers on my AFR's by 0.125" to get the geometry correct. This in turn changes pushrod length by ~0.200".

From their web site:

Pro Magnum Hydraulic Roller Lifters
Chevrolet Small block. For use in blocks originally equipped with hydraulic roller cam. 1987 to present, and GEN III, LS1, LS2, and LS6.

COMP Cams® Pro Magnum Hydraulic Roller Lifters™ are specifically designed to perform at higher engine speeds. When engines are equipped with a hydraulic camshaft, high rpm is limited by the improper position of the internal piston as the lifter inevitably "pumps up". This improper location results in open valves and therefore leads to lost power or sometimes even engine failure. NOTE: These lifters require an adjustable valve train (check here for adjustable valve train components), and must be pre-loaded to .002" to .004" for proper operation!