just a little AR
 

Started my 964 rebuild in October, maybe done in March. Takes time to get all the pieces powder coated, hardware recad plated, etc, and my traveling doesn't help.

Anyhow, I polished my heads with an industrial style gem polisher.

http://forums.pelicanparts.com/uploa...1109534800.jpg

Very nice.

So when I had it mostly together and was checking my chain alignments after I had just added a base cyliner shim, I decided to do a leak check to the cylinders. OOps. They all had leaks past my valves.

Rip off the heads and back to the machinist.
The polishing maybe should be done before the machinist does the valve grind.??

I thought there is no base cylinder shim in the 964.

There isn't. But my tops of the my cylinders were cut .018 inch to plane and make them all the same height, and my heads were cleaned up .002 inch. So I had a deck heigth of .031 inch. A little too close, and the expert opinion was either to add a single piece base shim or recess cut my heads. Jerry Woods made the shims and so I will give this a shot.

Did you polish with the valves in or out? Before or after rebuilding the valves? Before or after having the seats cut?

I did some sanding/polishing with valves out and final with valves in-all after the machinist completed the valve job. He is rechecking-i.e. he is going over with a stone and may relap them for me. Then I'll reasssemble. The local dealer mechanic says it may just be normal for a some leakage until the valves are actually used when the engine runs.

Well I'll disagree with the little leakage.......unless your in a big production shop and working on 350 chevy heads,,,,,,,even then it comes dwn to quality, pride, and workmanship....any valve job job you have to pay upwards to a g or more ought not leak at all.....If thir counting on the valve slaming shut enough times to fill the gap better think again as it will never get better.......just worse.
Is the valve head going to tilt?? is it going to conform to the seat??NO NO....not till much too late......................

Got heads back, tried one and I still get blow by. Will send to Walt at CE. He says he does a vacuum check. Oh well. I need to put new shingle siding on my house anyhow.

Update. Got heads back from Walt. Did leak test and basically no change. So I continued to assemble and now engine is ready to reinstall. We'll see what happens.

Post some pics of your rebuild before ... during... after the install.

Cheers,

Jason

curious, were the seats cut with a serdi machine or stones?
-h

http://forums.pelicanparts.com/uploa...1129782848.jpg

Ready for installation. I had a problem with tranny and will not get to put this in for at least a month.