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stock rockers on .621 lift cam

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Old 02-06-2011, 05:05 PM
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Default stock rockers on .621 lift cam

so how much lift can the stock LS1 rockers take. i know that they are pretty good, but can they take .621 lift without wrecking the valves or hurting the rockers? the springs i will be running are EHT .675 springs that are rated at:

1.800" = 161lbs
1.150" = 472lbs

is this to much spring pressure, together with a high lift cam for the stock rocker arms? if so then i need some suggestions for some aftermarket roller rockers. i was looking at the yella terra ultra lights.

-Thanks
Old 02-06-2011, 05:14 PM
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I have seen people use stockers with more lift,but I feel you should install the compcam trunnion bearings for stock ls rockers.you can get them at TSP.some told me the stock needle bearings aren't caged,and the comp cams are caged.they don't come out when abused.
Old 02-06-2011, 11:01 PM
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They will be fine.
Old 02-07-2011, 08:47 AM
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Originally Posted by 01ssreda4
They will be fine.
you mean they will be fine just how they are or will be fine with the upgraded bearings? i am not gonna see high RPM's all the time like the instructions say, i mostly drive it on the street and sees the track every summer for like 2-3 times a year.
Old 02-07-2011, 11:20 AM
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Check the wipe on the valve stem and then make your decision.
Old 02-07-2011, 11:21 AM
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i agree with the idea of the ugraded trunion kit. im in the process of doing a full motor rebuild and am doing the upgrade and cam. its really easy and when you pull the stocker rockers apart you will see how cheap they are.
Old 02-07-2011, 02:03 PM
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Originally Posted by 01ssreda4
They will be fine.
Correct, the stock rockers are actually really nice pieces. I wouldn't hesitate to run them up to .650" lift when set up properly.
Old 02-07-2011, 03:31 PM
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im runnin a .617 with the stock rockers and they are doing just fine.
Old 02-07-2011, 09:41 PM
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Originally Posted by Jon@HKE
Correct, the stock rockers are actually really nice pieces. I wouldn't hesitate to run them up to .650" lift when set up properly.
this is what i like to hear

Originally Posted by Ntimid8r7
im runnin a .617 with the stock rockers and they are doing just fine.
good, my lift will be just around there. i can always change them later if i dont like them
Old 02-08-2011, 04:13 AM
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Make sure you set up the geometry, just don't bolt them in.
Old 02-08-2011, 09:29 AM
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stockers geometrically are great. if you upgrade the trunion and be sure the wipe pattern is ok and they are setup good you should be fine. If you were concerned with breaking a rocker, you wont.
Old 02-08-2011, 09:57 AM
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^ x2.. Was gonna say for a little extra insurance, get the upgrade.
Old 02-08-2011, 10:09 AM
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Personally, I have had stock rockers lose their bearings while using higher pressure springs. Does it happen to people often, no. However, it does & can happen. The best thing to do is to upgrade the trunion, as advised in several comments already. If you were to lose a trunion cap, you'll be forever trying to make sure that every little needle bearing is found @ the very least.


Ntimid8r7, I dig the Al Bundy pic.
Old 02-08-2011, 12:21 PM
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i ran the stockers with a ms3 for 2 years and no probs....came across some harlan sharps for a deal....otherwise i would have never changed untill there was a problem....
for sale section of some other classified for used a set maybe or just keep stock rockers
Old 02-08-2011, 09:40 PM
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are the stockers even adjustable, you guys say check the wipe pattern, what would be a bad pattern, and if bad how do you change it if even possible?
Old 02-08-2011, 10:05 PM
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Originally Posted by trans_am7935
are the stockers even adjustable, you guys say check the wipe pattern, what would be a bad pattern, and if bad how do you change it if even possible?

You check w/ a fixed lifter & a pushrod length checker or w/ a stock lifter & soft valve springs installed for checking. Wipe pattern should be centered on the valve tip. It is adjusted by changing the pushrod length.
Old 02-09-2011, 04:21 AM
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Originally Posted by LS1-450
It is adjusted by changing the pushrod length.
Pushrod length won't effect the wipe pattern on the stock rockers because the pivot point is fixed relative to the valve stem.

You need to either shim the rockers up to move the pattern to the exhaust side or mill the rocker stand (aftermarket required here) to move the pattern to the intake side. With stock rockers it will be wide. I think you will find the rockers need to be lowered because of the lift you are running and therefore you will need an aftermarket rocker stand that will allow the height to be altered. This is not a place to cut corners.

There is a third method for checking, use check springs and a dial indicator. Rotate the rockers by hand through the required lift. This way the motor doesn't have to be rotated. This can also be done with the heads off the car. I find this method to be the easiest as it allows quick changes to setup with minimal work until you find the correct height.
Old 02-09-2011, 06:00 AM
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Have ran the ms4 for almost 2 years on the stockers have had no issues,but will upgrade with the trunion kit this spring
Old 02-22-2011, 08:54 AM
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so if i found a good deal on some yella terra's would you say to keep the stockers or use the better rollers with my high lift
Old 02-22-2011, 08:48 PM
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bump for answer


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