Need a little Help on Evaluating This Oil Pump
 

When I took my Oil Pump for my 930 apart to clean it I noticed that there is some scoring on the gears and on the intermediate plate. I am not sure if this is considered normal wear or if this pump has seen its day.

I am hoping someone with some oil pump experience can chime in.

Can the intermediate plate be trued up on a surface plate?

Here are the pics


http://forums.pelicanparts.com/uploa...1331397298.jpg


http://forums.pelicanparts.com/uploa...1331397321.jpg


http://forums.pelicanparts.com/uploa...1331397346.jpg


http://forums.pelicanparts.com/uploa...1331397373.jpg

http://forums.pelicanparts.com/uploa...1331397432.jpg


http://forums.pelicanparts.com/uploa...1331397457.jpg


http://forums.pelicanparts.com/uploa...1331397484.jpg

I think You should look for a new oil pump. The intermediate plante can be trued, but the scoring on the outer surface looks far worst.

If you choose to resuface the mid and end plates, it will decrease the inside measurment of the pump body.
So...you might have to also decrease the length of the gears to keep the clearance the same.
It will "tighten" up the pump...and perhaps make it more efficient....but consult the factory specs to see how much clearance the original pump needed.
Bob

Thanks for the replies!

Does anyone know what the factory clearance is for these pumps?

I'm thinking I can use shim stock between the gears to measure the clearance. I would imagine I could start at probably .003" re-assemble the pump and see if it binds. I'd then increase it or decrease .001 at a time to find out where the clearance is.

Has anyone had any experience re-building these?

I'm starting to lean to a new gt3 pump.....

Aaron Burnham (BURN-BROS) at Rennwerks has some experience with the different oil pumps used in the 911 and modifying them.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/548297-when-use-gt3-vs-930-pump.html

I actually was assembling my 993 pump today, so I know what you're talking about. My intermediate/thrust surfaces look excellent. But one side of the scavenge pump showed some noticeable wear on the housing. The two shaft bearing at the end of the scavenge housing show some wear on them too. I put it back together anyway.

Kinda bums me, considering the SC pump I removed looked fantabulous inside...... :mad:

Supertec rebuilds and modifies Porsche pumps and actually has a modification that increases the flow. I think I read 15% on the pressure side.
I think they buy damaged pumps as core parts if you choose to go with another pump.