[Z06] Push Rod Straightness Spec
Thread Starter
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Push Rod Straightness Spec
I'm in the middle of swapping out my valve springs and installing the Comp Cams Trunion Kit.
Pulled all the stock push rods to check their straightness. I don't have any V-blocks and a dial indicator to check them, so cleaned them up and rolled them on a nice flat piece of glass.
A few of them seemed to have a slight bow ... I measured under the high spot between the push rod and glass with a feeler gauge and the worse ones are at 0.003".
Is that acceptable? ... I would think it would be OK. I checked the shop manual and could not find a max run-out spec. I'm suspecting the OEM push rods aren't perfectly straight ... maybe aftermarket ones are as much as 0.003 out too (?).
Would it be worth installing a set of Comp Cams chrome-moly push rods while I have it opened up?
Or are the stock LS6 push rods strong enough for hard street use? I'm putting in PAC 1518 valve springs, so the valve force is only about 20 lbs higher at full lift.
Pulled all the stock push rods to check their straightness. I don't have any V-blocks and a dial indicator to check them, so cleaned them up and rolled them on a nice flat piece of glass.
A few of them seemed to have a slight bow ... I measured under the high spot between the push rod and glass with a feeler gauge and the worse ones are at 0.003".
Is that acceptable? ... I would think it would be OK. I checked the shop manual and could not find a max run-out spec. I'm suspecting the OEM push rods aren't perfectly straight ... maybe aftermarket ones are as much as 0.003 out too (?).
Would it be worth installing a set of Comp Cams chrome-moly push rods while I have it opened up?
Or are the stock LS6 push rods strong enough for hard street use? I'm putting in PAC 1518 valve springs, so the valve force is only about 20 lbs higher at full lift.
Last edited by ZeeOSix; Jul 5, 2011 at 11:15 PM.
Thread Starter
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Just trying to decide if I should get the 7.400" length or the 7.375" length since Comp Cams goes by "gauge length" which means their 7.400 pushrod is actually slightly longer than the OEM pushrod which has a gauge length around 7.385".
Comp Cams recommends the 7.400" for the Gen III LS1/LS2/LS6 engines ... so I would assume they have reasons for recommending the 7.400" over the 7.375" length.
Last edited by ZeeOSix; Jul 7, 2011 at 06:01 PM.
Burning Brakes
Joined: Jul 2005
Posts: 788
Likes: 33
From: Cedar Rapids IA
Yeah, I've decided to buy some Comp Cams chrome-moly pushrods since I'm into the motor anyway.
Just trying to decide if I should get the 7.400" length or the 7.375" length since Comp Cams goes by "gauge length" which means their 7.400 pushrod is actually slightly longer than the OEM pushrod which has a gauge length around 7.385".
Comp Cams recommends the 7.400" for the Gen III LS1/LS2/LS6 engines ... so I would assume they have reasons for recommending the 7.400" over the 7.375" length.
Just trying to decide if I should get the 7.400" length or the 7.375" length since Comp Cams goes by "gauge length" which means their 7.400 pushrod is actually slightly longer than the OEM pushrod which has a gauge length around 7.385".
Comp Cams recommends the 7.400" for the Gen III LS1/LS2/LS6 engines ... so I would assume they have reasons for recommending the 7.400" over the 7.375" length.
