I just had a valve job done on a v8. I asked "were the valves lapped in?"
answer: no.
Is there a new school of thought on this process.
He did say that the valves were vacuum tested, and tested ok.
thoughts??
I just had a valve job done on a v8. I asked "were the valves lapped in?"
answer: no.
Is there a new school of thought on this process.
He did say that the valves were vacuum tested, and tested ok.
thoughts??
If they vacuum tested OK they should be fine. I think the theory is that modern machining methods are precise enough that lapping really doesn't accomplish anything.
nate
I only lap valves in heads that do not really need valve grind work. IE, if one is replacing the seals, might as well lap the valves/seats.
JT
If they passed the vacuum test,all will be fine. I'm a bit peculiar, I hand lap lightly with fine compound to check for a perfect sealing surface.
Freddy
Grumpy AuC>
Yea, the wet method is more accurate.
Using vacuum, "IF"...they actually did it is actually pulling the valve toward the seat...plus if they don't have very accurate gages...they won't see any leak. Using vacuum to seat the valve AND check for leaks is cheating. If they are listening...for a leak..use a new shop!
I normally don't bother checking the heads I have done. I'm not gonna admit how I do it but the shop I use has never given me a bad valve grind. I do my own assembly when I port heads, he just does the grinding.
He uses (as noted above) a 45 degree head cut and a 46 degree valve cut on his street stuff. On hot rod or race heads, it's 45 - 45.
Mike
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