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#1
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Valve stem installed height
Hi all, just got my head back from the machine shop and I just want to do a quick check to make sure the stems are at the correct height but I can’t find the specifications anywhere. Does anyone have this info close by? Thanks in advance , Neill
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69 Firebird, 462 turbo 400 3000 stall, 8.5 323 rear |
#2
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When I die, I want to go peacefully like my grandfather did, in his sleep. Not screaming like the passengers in his car. |
#3
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Thanks Jeff, I will go over all that this morning
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69 Firebird, 462 turbo 400 3000 stall, 8.5 323 rear |
#4
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Great info, but Jeff (or whoever he got it from) misplaced a digit. The first number in the red line should be 0.850", not 0.085"
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My Pontiac is a '57 GMC with its original 347" Pontiac V8 and dual-range Hydra-Matic. |
#5
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Thanks for the catch.
Corrected;
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When I die, I want to go peacefully like my grandfather did, in his sleep. Not screaming like the passengers in his car. |
#6
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When you say that you diamond lap the followers, do you mean that you use a lapping compound on the hardened surface that rides on the cam? Do you also do the other contact points? Do you use a lapping stone or any flat surface? I may be pulling my cam housing back off due to second guessing myself about oil passages and the gasket possibly not being lined up properly. If I do i will try dressing the followers as you suggest.
The valve tips were all at .840 with 3 being an additional .004 to .008 thousandths shorter. I'm hoping that as the valve job breaks in the stems will grow a little. Neill
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69 Firebird, 462 turbo 400 3000 stall, 8.5 323 rear |
#7
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IIRC This outline was written by Richard McDonough so not sure how he does his.
In the past, my local machine shop did any I needed. You might reach out to Rob he now owns/runs Woodland Sports and should have any/all related info on this process. https://www.facebook.com/Woodland-Mo...location=group
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When I die, I want to go peacefully like my grandfather did, in his sleep. Not screaming like the passengers in his car. |
#8
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Okay, thanks again Jeff. I did buy a few pieces from Rob already so I may talk to him again.
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69 Firebird, 462 turbo 400 3000 stall, 8.5 323 rear |
#9
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Hey Jeff, it seems that whatever you posted in post # 2 is no longer there. Can you re-post the measurements and possibly how to measure the valve stem height? Thank you!
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#10
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...
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When I die, I want to go peacefully like my grandfather did, in his sleep. Not screaming like the passengers in his car. |
#11
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Thank you Jeff. Is that .850" measured from the plane that the cam cover bolts to up to the top of the valve stem?
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#12
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Yes. It sounds easier than it seems. I remember using feeler gauges, micrometer and straight edges. I also remember using some basic geometry to get the measurement. PITA. Towards the end it was more of a go no go confirmation. Maybe Jeff has some tricks.
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#13
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When I die, I want to go peacefully like my grandfather did, in his sleep. Not screaming like the passengers in his car. |
#14
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Great info, thank you very much! I'm guessing this measurement would also change with a valve that has tuliped in the head effectively lengthening the valve stem? Still not sure what the full issue is with mine, been too cold here to pull it apart. But, having this info will no doubt lead me down the right path. Thanks again!
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#15
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When I did mine, like 8 of the 12 were all right in the middle. 2 were like 5 thousands off and 2 were on the ragged edge, just barely in spec. If I do it again, I will make up a T square equal to the bottom tolerance. Then use a feeler gauge to see how far off the bottom I sit. The biggest issue was I needed like 4 hands to hold everything in place while I measured.
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