Valve stem height
March 26th, 2020, 05:02 PM
#1
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Join Date: Oct 2013
Posts: 36
Valve stem height
Anyone have one of those fancy stem height checking tools they could loan me?? Or know of another way to check valve stem height?? I guess i could measure it with a caliper....does anyone know the correct height from the seat?
March 28th, 2020, 06:45 AM
#2
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Join Date: Dec 2016
Location: Beautiful Southern Maryland
Posts: 1,490
Tim,
I have one of the actual GM factory tools. I have a drawing I made of the dimensions but don't have it on my computer here at home. A word of warning, some of the aftermarket tools are not correct. I had a customer bring me one along with a set of heads to do a few years back. Something did not make any sense with the tool compared to the valve stem height listed in my engine builders software. So I managed to get hold of the GM tool from a friend. The aftermarket tool was quite a bit off.
The valve stem height listed in my engine rebuilders software is 2.016" to 2.046" I have found that is pretty close but the spring seat machining leaves something to be desired.
If you can wait till Monday I will get the dimensions of the tool. Joe P might have to drawing too, I think I had e-mailed it to him.
I have one of the actual GM factory tools. I have a drawing I made of the dimensions but don't have it on my computer here at home. A word of warning, some of the aftermarket tools are not correct. I had a customer bring me one along with a set of heads to do a few years back. Something did not make any sense with the tool compared to the valve stem height listed in my engine builders software. So I managed to get hold of the GM tool from a friend. The aftermarket tool was quite a bit off.
The valve stem height listed in my engine rebuilders software is 2.016" to 2.046" I have found that is pretty close but the spring seat machining leaves something to be desired.
If you can wait till Monday I will get the dimensions of the tool. Joe P might have to drawing too, I think I had e-mailed it to him.
June 7th, 2021, 03:23 PM
#4
Tim,
I have one of the actual GM factory tools. I have a drawing I made of the dimensions but don't have it on my computer here at home. A word of warning, some of the aftermarket tools are not correct. I had a customer bring me one along with a set of heads to do a few years back. Something did not make any sense with the tool compared to the valve stem height listed in my engine builders software. So I managed to get hold of the GM tool from a friend. The aftermarket tool was quite a bit off.
The valve stem height listed in my engine rebuilders software is 2.016" to 2.046" I have found that is pretty close but the spring seat machining leaves something to be desired.
If you can wait till Monday I will get the dimensions of the tool. Joe P might have to drawing too, I think I had e-mailed it to him.
I have one of the actual GM factory tools. I have a drawing I made of the dimensions but don't have it on my computer here at home. A word of warning, some of the aftermarket tools are not correct. I had a customer bring me one along with a set of heads to do a few years back. Something did not make any sense with the tool compared to the valve stem height listed in my engine builders software. So I managed to get hold of the GM tool from a friend. The aftermarket tool was quite a bit off.
The valve stem height listed in my engine rebuilders software is 2.016" to 2.046" I have found that is pretty close but the spring seat machining leaves something to be desired.
If you can wait till Monday I will get the dimensions of the tool. Joe P might have to drawing too, I think I had e-mailed it to him.
Can you clarify your valve stem height specs "listed in my engine rebuilders software is 2.016" to 2.046"versus the height from the webpage below which mentions 2 heights based on the retainers/rotators "1966 and up 400 and all 455’s without rotators; 1.880" and 2.035” for 455’s with rotators."
http://www.supercarsunlimited.com/in.../stem/stem.htm
best regards,
John
June 7th, 2021, 06:19 PM
#5
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Join Date: Dec 2016
Location: Beautiful Southern Maryland
Posts: 1,490
John,
I just looked again and on certain years there is a note saying that the non rotator heads are 1.8760-1.9060 Those heads must have a shallower spring pocket. On Olds heads though what is mainly important is the height of the stem compared to the valve cover rail because of the non adjustable valve train. I have found that factory spring pockets are very inconsistant
I just looked again and on certain years there is a note saying that the non rotator heads are 1.8760-1.9060 Those heads must have a shallower spring pocket. On Olds heads though what is mainly important is the height of the stem compared to the valve cover rail because of the non adjustable valve train. I have found that factory spring pockets are very inconsistant
June 9th, 2021, 09:59 AM
#7
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 48,237
By the way, here's a clever way to make your own version of the Olds tool.
June 9th, 2021, 12:06 PM
#8
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Join Date: Dec 2016
Location: Beautiful Southern Maryland
Posts: 1,490
No because the difference is that the head is machined deeper to allow for the thickness of the rotators. The height above the valve cover rails / rocker mount has to be the same or you would need different length pushrods. I dont have an Olds rotator here to measure but Chevy ones are around .200 thick.
June 9th, 2021, 12:27 PM
#9
OK, I get it now....
The different measurements are from the base to the top of stem which differ from rotator and a non-rotator
The tool uses the head rail but should be similar to both in depth to the top of the stem.
correct?
cheers,
John
The different measurements are from the base to the top of stem which differ from rotator and a non-rotator
The tool uses the head rail but should be similar to both in depth to the top of the stem.
correct?
cheers,
John
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