Valve lapping compounds

[Sonny]

I just lapped my valves and seats with the larger grit permatex grinding compound and have a nice gray surface. Do I need to go further with a finer grit compound?

 

[66Satellite47]

I always just used the Permatex grey. Valves will make the finish. But you could go to the white Dupont polishing paint compound if you want.

 

[wyrmrider]

waste of time valve head expands when hot and is now off your new so called seat

 

[493 Mike]

A finely machined valve seat is superior to anything done by hand. Learned that in Auto Machine Shop in college 48 years ago.
Mike

 

[zyzzyx]

I use "Clover" brand lapping compound for finishing valves. 400grit. It comes in a green half-pint can.
Industrial use mostly. Permatex makes some lame products such as their lapping compounds and
their Prussian Blue. Dye-Kem makes the best Hi-Spot hands down.
Just went on Flea-Bay, and saw an original 16oz. can for $5.75 +$2.75 shipping!
What a deal. And, I guess Loctite owns Clover now! All different grits available.

 

[dvw]

I use lapping as a way of keeping an eye on the valve job. Car has been 9.0@150, 3340#. It can't have hurt it to bad
Doug