95 lt1
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95 lt1 Ok. I'm spend about an hour looking around on here for the correct thread describing my problem. So I'm sorry if I missed it but here's my issue.
I'm rebuilding a stock LT1. The block if from a 96 fire bird and the heads are from a 95 impala SS. " not really desired but it's what I have"
I been following the book on this one because I've never really rebuilt an engine before. Well I installed the new lifters and new push rods. Put the rockets in place and stared to tourqe them down. After about 4 I decided to just rotate the engine to make sure nothing would hit so I wasn't wasting a lot of time undoing everything. Well I noticed on the cylinders I torqued, the cam is in the closed position and the valve is about a 1/4 of the way open. The lifters "squished". Stock cam. Stock rockers. Stock push rods. Everything is seated properly. I'm at a loss.
I'm rebuilding a stock LT1. The block if from a 96 fire bird and the heads are from a 95 impala SS. " not really desired but it's what I have"
I been following the book on this one because I've never really rebuilt an engine before. Well I installed the new lifters and new push rods. Put the rockets in place and stared to tourqe them down. After about 4 I decided to just rotate the engine to make sure nothing would hit so I wasn't wasting a lot of time undoing everything. Well I noticed on the cylinders I torqued, the cam is in the closed position and the valve is about a 1/4 of the way open. The lifters "squished". Stock cam. Stock rockers. Stock push rods. Everything is seated properly. I'm at a loss.
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From: Tucker, GA
Did you soak the lifters in oil for a few hours? If not, I'd suggest you do. From what it sounds like, you've torqued down the rockers until you've overly compressed the lifter plunger. You don't "torque" the rockers. They are installed first and then you set the lash. There are a few different ways, but CompCams has a pretty good "how to". FYI, if you do this incorrectly, you run the risk of ruining your engine - so do be careful.
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I didn't soak them just dunked them in a pan of clean oil. These rockers don't have lash adjustment. They are set but the hydraulic lifters. I keep thinking the push rods are too long but the are the same length that came out. And I feel that just getting shorter push rods is a bandage fix.
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From: Houston
Your RR's are most likely adjusted incorrectly resulting in the lifters and springs being compressed.
Remove the RR's and the lifters. Let the lifters soak in oil over night and then reinstall them. My rule of thumb is generally to tighten down throckers just enough to where the pushrods don't spin freely. I then give an additional 1/4 to 1/2 turn before locking them.
You may here some clacking when you first fire it up, but it should dissipate quickly. If the clacking doesn't go away in the first 5-10 seconds then one or more of your valves is out of adjustment. If you readjust and the clacking still occurrs, you may have collapsed a lifter as a result of your prior attempts at adjusting the rocker arms/valvetrain.
To triple check, start the engine with the valve covers off and try to identify which valve is clacking and adjust the rocker arms with the motor running. If you tighten it down and the noise goes away it might have just been improper adjustmemt, but if poor running and poor performance ensues, replace your lifters.
In the past, I have set the rough adjustment by hand with the motor off then come back and reset the lash a second time with the motor running. I tend to keep my valvetrain a little looser than most though.
Remove the RR's and the lifters. Let the lifters soak in oil over night and then reinstall them. My rule of thumb is generally to tighten down throckers just enough to where the pushrods don't spin freely. I then give an additional 1/4 to 1/2 turn before locking them.
You may here some clacking when you first fire it up, but it should dissipate quickly. If the clacking doesn't go away in the first 5-10 seconds then one or more of your valves is out of adjustment. If you readjust and the clacking still occurrs, you may have collapsed a lifter as a result of your prior attempts at adjusting the rocker arms/valvetrain.
To triple check, start the engine with the valve covers off and try to identify which valve is clacking and adjust the rocker arms with the motor running. If you tighten it down and the noise goes away it might have just been improper adjustmemt, but if poor running and poor performance ensues, replace your lifters.
In the past, I have set the rough adjustment by hand with the motor off then come back and reset the lash a second time with the motor running. I tend to keep my valvetrain a little looser than most though.
Last edited by Gangly; Mar 7, 2017 at 12:38 PM.
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From: Tucker, GA
Read the link I posted above. Its applicable to any engine with hydraulic pushrods, and good for any rocker arm.
Last edited by atlantadan; Mar 7, 2017 at 12:31 PM.
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From: Tucker, GA
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Ok I apologize. While I was reading the manual I seen a torque spec and just assumed the lifters would make up the difference. But I just started reading another manual and it has a different way or setting them. Thank you for the info.
