jdog

So I had my head rebuilt by a very reputable machine shop who does work for several racers on the NASCAR circuit, but not being real familiar with Porsche engines the machinist did not do anything with the relief valve in the head. My question is what is your advice on what I should do.

A). remove and replace the valve or at least clean it up
b). not worry about it

I am also looking for a one piece OPRV and if anyone has an extra balance shaft bearing that they would like to part with I need both.
Thanks..

Chris White

If the head was surfaced you should remove the relief valve and make sure there is no metal filings in there.
There are several different types of one piece OPRV…you need ot say what year.
There are also two different types of rear balance shaft bearings…need to know year and does it have separate bearing caps.

jdog

Sorry about that was in a hurry. 86 951. Looking for the balance shaft bearings located in the front of the engine. I guess they call them the bearing shells. Part number is:
944.101.125.02 I believe.
Is is fairly easy to do the relief valve in the head. Sounds pretty straight forward, but Murphys law I am sure will apply.

theedge

The parts for the cylinder head valve are dirt cheap. $5 total. I just bought them last week from pelican.

There's a 3 piece one and a one piece unit that's $300 or so. No functionality difference from my reading, and neither supercedes the other.

Chris White

BUZZZZZ. – wrong answer! Thanks for playing and please pick up your consolation prize on your way out….

The 3 piece OPRV was replaced by the 1 piece design in 87 (these are not interchangeable). Porsche also introduced a 1 piece OPRV that replaces the earlier (pre 87) 3 piece version.

The 3 piece design has a tendency to fail if it has been taken apart. The wear patterns don’t mesh well if it is disturbed.

jdog

That is exactly what I thought too. Not the same.
Anyone out there have an extra OPRV they would like to sell?
Still looking for that bearing also.
Thanks

Charlie

PM tod84944 I think he has an OPRV you could buy.

I had to replace a rear bs bearing and bought a new one at Paragon.

theedge

Bzzzzzzzzt, I was talking about the cylinder head OPRV. I think you are talking about the main OPRV? The cylinder head valves are both still listed and available.

reno808

lol