How come the Viton valve seals are too tight?
11-15-2012, 12:32 PM
#1
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How come the Viton valve seals are too tight?
Hello,
I purchased some blue Viton 3/8" by .562 valve seals for my 68 427/390 BB.
The valve stems are 3/8" not 11/32nds before anybody asks me to check stems. Heads are stock style cast.
The intake guides were machined down to .560 by unknown shop by a PO.
I purchased the Viton intake seals that are the positive control style with a solid base ring and a spring reinforced ring near the top.
After lubing with engine oil and attempting to slip over valve stem it feels too tight my hunch is this is wrong?
The nylon PC style seals I removed were torn in half horizontally and did not appear that old. I can not believe in my mechanical inclination that these are going to last being this tight on the valve stem. I can't even get them 1/2 down the stem
Yet this is the correct application according to several suppliers.
No problems on the exhaust guides as they remain stock and I have Viton umbrella seals for them. They clear the double springs fine.
Do I just put the umbrella type on the intake as well and forget about PC style for Intake guides?
Frustrated,
Marshal
I purchased some blue Viton 3/8" by .562 valve seals for my 68 427/390 BB.
The valve stems are 3/8" not 11/32nds before anybody asks me to check stems. Heads are stock style cast.
The intake guides were machined down to .560 by unknown shop by a PO.
I purchased the Viton intake seals that are the positive control style with a solid base ring and a spring reinforced ring near the top.
After lubing with engine oil and attempting to slip over valve stem it feels too tight my hunch is this is wrong?
The nylon PC style seals I removed were torn in half horizontally and did not appear that old. I can not believe in my mechanical inclination that these are going to last being this tight on the valve stem. I can't even get them 1/2 down the stem
Yet this is the correct application according to several suppliers.
No problems on the exhaust guides as they remain stock and I have Viton umbrella seals for them. They clear the double springs fine.
Do I just put the umbrella type on the intake as well and forget about PC style for Intake guides?
Frustrated,
Marshal
11-15-2012, 03:02 PM
#2
Team Owner
Possibilities:
The seals are "blue", but are not made of Viton material and they have shrunk. Cause: Cheap, gypo, junk from a low-budget, low-quality source. (Yes, this happens. More in a down-turning economy.)
The vendor packaged the "wrong" seal in the "right" package.
The valve stems are not the size you think they are.
I hope you are able to find a good fix for your problem.
The seals are "blue", but are not made of Viton material and they have shrunk. Cause: Cheap, gypo, junk from a low-budget, low-quality source. (Yes, this happens. More in a down-turning economy.)
The vendor packaged the "wrong" seal in the "right" package.
The valve stems are not the size you think they are.
I hope you are able to find a good fix for your problem.
11-16-2012, 08:49 AM
#3
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7T1vette,
thanks for your response.
You are always quick to provide help
I called the vendor yesterday and we walked through it together over the phone.
When I get back to the shop I will lube same and try again.
If I have the wrong seals by some mislabeling, he will send new ones no problem. He has been very helpful and valve trains is all he does.
They are real Viton according to him.
Marshal
thanks for your response.
You are always quick to provide help
I called the vendor yesterday and we walked through it together over the phone.
When I get back to the shop I will lube same and try again.
If I have the wrong seals by some mislabeling, he will send new ones no problem. He has been very helpful and valve trains is all he does.
They are real Viton according to him.
Marshal
11-16-2012, 04:04 PM
#4
Team Owner
If they are super-tight and require a lot of stretching to fit over the valve stems, either the valve stems are a different diameter or the seals were mis-packaged.
11-17-2012, 05:42 AM
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Ironcross,
sorry, I missed your response until I checked my verizon email.
Yes, the intake side only has been milled to .560 by unknown shop
by previous owner but not the person I purchased the car from.
I called him and he said when he purchased it the seller did not mention anything regarding engine rebuilt when he purchased back in 2008.
He had no idea who did the work or where and when time frame.
The exhaust guides were left untouched.
I hope to have a chance next Tuesday on my next day off to dive into it some more. I'll update this thread with additional findings.
Thank you,
Marshal
sorry, I missed your response until I checked my verizon email.
Yes, the intake side only has been milled to .560 by unknown shop
by previous owner but not the person I purchased the car from.
I called him and he said when he purchased it the seller did not mention anything regarding engine rebuilt when he purchased back in 2008.
He had no idea who did the work or where and when time frame.
The exhaust guides were left untouched.
I hope to have a chance next Tuesday on my next day off to dive into it some more. I'll update this thread with additional findings.
Thank you,
Marshal