G5X3 pushrod question

Reply Subscribe

Thread Tools

Search this Thread

Jan 28, 2007 | 09:57 AM

FourG63 97GST

Thread Starter

Melting Slicks

Joined: Mar 2006

Posts: 2,753

Likes: 379

From: South Florida FL

G5X3 pushrod question

well I ordered my cam (G5X3 114), just shopping for the other pieces of the puzzle.

what length pushrod do I go with. factory length hardened? which is what 7.400?

Jan 28, 2007 | 10:03 AM

calvette 11

Racer

Joined: Feb 2005

Posts: 374

Likes: 4

From: decatur ga

push rods

use comp 7955-16
These are hardened,stock length

Jan 28, 2007 | 10:06 AM

Corvette-Chris

Le Mans Master

Joined: Jul 2005

Posts: 7,121

Likes: 3

From: Shreveport/Bossier Louisiana

St. Jude Donor '08

I also got the Comp hardened stock length

Jan 28, 2007 | 10:23 AM

vettenuts

Team Owner

Joined: Mar 1999

Posts: 22,025

Likes: 192

From: At the beach in little Rhody

Personally, I would measure. The aftermarket cams use a smaller base circle on the lobe, therefore the lifter sits lower in the lifter bore. With the same length pushrod, your lifter preload will decrease. You likely need 7.425" pushrods, but a measurement would confirm. I think "Cobra4B" just installed this cam and measured, you might want to check with him.

Jan 28, 2007 | 01:43 PM

94legaleagle

Melting Slicks

Joined: Mar 2005

Posts: 2,364

Likes: 1

From: Rugby North Dakota

Question has been asked and answered here a few times recently - guaranteed method to be correct is to use a pushrod legnth checker - I called LG and asked, and they said use stock legnth, which is 7.40" hardened pushrods - other's are using the 7.425" rods

Major thing you might notice difference wise between the above two rods is a little more lifter noise - some call it a "sewing machine" noise - some say they end up w/ this sewing machine noise, other's say they don't - some say they have the noise w/ either size pushrod

I went w/ the 7.40" rods on my AFR 205 heads and G5X3 cam - I haven't fired it up yet, so I don' know what, if any noise I'll notice - worst case I guess is that I have to get 7.425 rods later.

Jan 28, 2007 | 02:19 PM

Y2Kvert4me

Race Director

Joined: Oct 2002

Posts: 16,477

Likes: 26

From: Gone

CI 6-7-8-9-10 Veteran

St. Jude Donor '03

I would suggest 7.425" unless it's an 02 or later Z06, then use 7.400"

I'm using 7.425" with my G5X4 and stock heads, and the valvetrain is dead quiet.

94legaleagle, if you decide you want to switch to the 7.425" after you get your car running, I'm looking to trade my TR 7.425" for some 7.400" since I'm putting some milled heads on in a month or so and will need the shorter ones. Keep me in mind if you'd be interested in an even swap.

Jan 28, 2007 | 03:22 PM

RonSS

Racer

Joined: Jul 2006

Posts: 285

Likes: 1

From: Placentia CA

Your profile says you have on 02 Z06. The base circle of you stock 02 LS6 cam is about .050 smaller than a stock LS1 cam. That’s why the longer valve stems on 02 and later LS6 heads. If the only thing your going to change is the cam and valve springs then measure the base circle of each cam. Half the difference is your new pushrod length.

Example:
Old cam base circle .775
New cam base circle .725
Diffrence is -.050
New pushrod length +.025 longer than old pushrod

Even though the cam is .050 smaller total it’s only .025 smaller on a side. The lifter will only be .025 closer to the cam center line. I bet your new cam will have a base circle close enough to your stock LS6 cam that you can use stock length (7.400) pushrods.

Jan 28, 2007 | 07:23 PM

Cobra4B

Team Owner

Joined: Mar 2001

Posts: 25,889

Likes: 7

From: Virginia Beach

CI 3-5-6-7-8 Veteran

I installed 7.4s which are sold as "stock length" however the stockers are really 7.38 or so... comparing the two side by side the 7.4s are longer.

I installed them w/ Yella Terra roller rockers and the valvetrain is very quiet... the sewing machine sounds is no more than stock was.