Chrome-Moly Pushrod Upgrade
Thread Starter
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Chrome-Moly Pushrod Upgrade
I'm going to put some PAC 1518 valve springs in my 2002 Z06 so I can stop worrying about an OEM spring failure. Was wondering if I should also upgrade the push rods to something like the Comp Cams Hi-Tech Chrome-moly while I have it apart. BTW - the PAC 1518s only increase the full lift load from 294 lbs (with stock springs) to 302 lbs with the stock LS6 cam and 1.7 rocker arms.
1) Are the stock LS6 pushrods a "weak link" even with the stock cam & valve train, and is it also worth replacing them for peace of mind?
2) Any issues with replacing just the pushrods in terms of having new push rods mating with used lifters and rocker arms (~21K miles on them)?
1) Are the stock LS6 pushrods a "weak link" even with the stock cam & valve train, and is it also worth replacing them for peace of mind?
2) Any issues with replacing just the pushrods in terms of having new push rods mating with used lifters and rocker arms (~21K miles on them)?
Last edited by ZeeOSix; May 15, 2011 at 09:17 PM.
Le Mans Master
Joined: Dec 2005
Posts: 8,589
Likes: 976
From: Communist Colorado
I would say you will be fine. If I were you, I would spend the money on the Comp Cam rocker upgrade for $200. I have read of more rocker truninon failures than push rod failures (if any) using a stock cam.
Should you decide to upgrade the pushrods you wont have any other issues.
Should you decide to upgrade the pushrods you wont have any other issues.
Last edited by 81c3; May 15, 2011 at 10:23 PM.
Thread Starter
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
I would say you will be fine. If I were you, I would spend the money on the Comp Cam rocker upgrade for $200. I have read of more rocker truninon failures than push rod failures (if any) using a stock cam.
Should you decide to upgrade the pushrods you wont have any other issues.
Should you decide to upgrade the pushrods you wont have any other issues.
Does that Comp Cams retro-fit trunion upgrade require any machine shop work, or is it something one can do in the garage with hand tools?
Maybe I should get that rocker upgrade kit and the chrome-moly pushrods too. This valve train stuff in never ending it seems, and I'm having a tough time trying to determine what's really needed or not.
BTW - I haven't read of any rocker arm failures since back when the 2001 Z06 came out and there were some rockers that puked their needle bearings - there was a TSB about it if I recall correctly. I thought GM had that fixed after 2001 (?).
Last edited by ZeeOSix; May 15, 2011 at 10:49 PM.
Le Mans Master
Joined: Dec 2005
Posts: 8,589
Likes: 976
From: Communist Colorado
Are you talking about the Comp Cams LS1 rocker arm retro-fit trunion kit that replaces the cageless, loose OEM needle bearings? One source calls it a LS1 trunion upgrade kit ... but I'm assuming it also works with the LS6 rockers?
Does that Comp Cams retro-fit trunion upgrade require any machine shop work, or is it something one can do in the garage with hand tools?
Maybe I should get that rocker upgrade kit and the chrome-moly pushrods too. This valve train stuff in never ending it seems, and I'm having a tough time trying to determine what's really needed or not.
BTW - I haven't read of any rocker arm failures since back when the 2001 Z06 came out and there were some rockers that puked their needle bearings - there was a TSB about it if I recall correctly. I thought GM had that fixed after 2001 (?).
Does that Comp Cams retro-fit trunion upgrade require any machine shop work, or is it something one can do in the garage with hand tools?
Maybe I should get that rocker upgrade kit and the chrome-moly pushrods too. This valve train stuff in never ending it seems, and I'm having a tough time trying to determine what's really needed or not.
BTW - I haven't read of any rocker arm failures since back when the 2001 Z06 came out and there were some rockers that puked their needle bearings - there was a TSB about it if I recall correctly. I thought GM had that fixed after 2001 (?).
Yea, thats what I am talking about. I did it through Hinson Motorsports. It was $200. with return shipping and a 4 day turn around. You can do it at home if you have a press... but for the 60 bucks, I let them do it for me.
I really dont know when the needle bearing troubles were fixed exactly, but Im a proactive sort of guy. I try to upgrade the parts of my engine with longevity in mind.
I did a cam on my Z, so I thought about the complimentary replacement parts and changed them. Of course the timing gears and chain, oil pump, crank pulley, water pump and belts. In addition to the cam, the springs, valve seals, retainers/locks, push rods and then the rocker trunion upgrade. I didnt pull the heads, or I would have done the liftrers also.
As far as whats really "needed".... youre probably fine with just the spring replacement if you have no further mods planned.
Thread Starter
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
I can't really recall much talk about the stock LS6 rocker arms having issues (except way back on the 2001 model). From what ls3gotcha said, and a few other threads I've read, it seems the stock pushrods could be a boarder line weak link even in the stock valve train if the car is pushed hard. I'll probably upgrade the pushrods ... it certainly can't hurt.
Does anyone know if the stock LS6 pushrods are chrome-moly or what the wall thickness is?
Last edited by ZeeOSix; May 16, 2011 at 02:42 AM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Not sure on wall thickness. Per my personal measurements, the stock pushrods are 7.385" gauge length. The fact that stock length is 7.400" is internet myth that came about because this was the defacto replacement when vendors installed a cam. So if you change, be aware the pushrods will be 0.015" longer. You may actually want to get the 7.375" gauge length instead.
Thread Starter
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Not sure on wall thickness. Per my personal measurements, the stock pushrods are 7.385" gauge length. The fact that stock length is 7.400" is internet myth that came about because this was the defacto replacement when vendors installed a cam. So if you change, be aware the pushrods will be 0.015" longer. You may actually want to get the 7.375" gauge length instead.
I know there are different ways to measure the pushrods, so not sure why Comp Cams is saying 7.400" for the LSx.
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