Valve/valve seat angle?

Performance mods and Advanced Stroker discussion.
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car5car
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Joined: November 27th, 2024, 7:25 am
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Valve/valve seat angle?

Post by car5car »

99-up valves have very strange specs:
valves 46.5 degrees
seats 44.5 degrees
How can it seal if there is 2 degrees difference?
More important question: can I cut seats with 45 degrees cutter?
What are 99-up and 98-down valve diameters?
Thanks.
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Cheromaniac
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Re: Valve/valve seat angle?

Post by Cheromaniac »

car5car wrote: November 27th, 2024, 7:40 amWhat are 99-up and 98-down valve diameters?
1.91" intake, 1.50" exhaust
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Re: Valve/valve seat angle?

Post by 75SV! »

The different angles helps seal on the outer edge. I had the heads on my LS 5.3 for my Chevy Avalanche done to 37 degrees. The guy doing the set of heads said something like 37 degrees and 38 degrees. I did do 30 degrees to a couple of '99 4.0L heads.
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