oil pump...

[geof33]

A subject came up today as to whether or not to plink down the $$$ for a new oil pump "while I'm there". From a purely visual perspective, it looks fine. I have no idea how the oil pressure was because I never ran the engine. As far as I know the pump has 200,000 miles on it.

I could leave it... What are the possibilities of failure?
Do the 930 pump... machining $$$
Do a new 911 pump...
OR do a total upgrade to the 993 pump, machining the case etc...

Opinions???

[Steve@Rennsport]

Geof33:

Determining whether an oil pump needs to be replaced is a matter of experience is assessing the wear & condition of the gears and pump body. I've seen pumps all worn out from poor maintenance at 125K and some beautiful ones at 125K from good oil change discipline.

I will tell you:

1) An SC or Carrera pump is a good one

2) A 930 pump is much much better IF you need that

3) A GT-3 RS pump is even better,...

4) A 3.6 pump (964-993) is to be avoided at all costs. Its a step backwards.

If you use either of the big pumps: 930 or GT-3R, you will need the shorter driveshaft and the case must be clearanced for those.

[Tyson Schmidt]

Steve, you've got me scared at the 964/993 pump comment. I recently built a 3.2 into a 3.4 , and the client insisted on a 964 pump which he supplied. We used ARP rod bolts, Max Moriitz P's/C's, and 993SS cams, with a custom reprogrammed chip by Steve Wong with a 7200 rev limit. He tracks the car hard.

How in peril is this engine with this oil pump?

[Henry Schmidt]

I agree with Steve on all counts.
When trying to decide whether or not to reuse a pump, my main concern is " did the pump have a healthy diet? "
Oil is good, chucks of anything are bad. If the pump housing shows little or no wear and the gears look smooth , run it.
In the early race days my boss had me wet sand each gear to make it as smooth as possible, by hand. You got it, great fun!!!
The 964 is made a magnesium so they a susceptible to heat expansion around the steel gears so consistent oil flow is a question. The mag housings also crack occasionally. These are the only Porsche pumps that I have ever seen crack.
Are 964 pumps bad? no
Do they have some design flaws? I believe so.
Would I take an engine apart to replace the pump if the engine had no symptoms? Absolutely not!!!

[Steve@Rennsport]

Henry is right,......

If the engine has good oil pressure, then I would not be concerned. I would be fastidious about oil changes though, and perform that at 2K intervals.

Next time, override the customer's requests and sell him/her a more durable & rugged pump if the motor will see track use.

Just for fun, look at the inlet/outlet port sizes on the 3.6 pump and compare that to the Turbo or GT-3R pump,...

[geof33]

So... To sum up, you guys are all concuring that, if the car is tracked... upgrade the pump. The car will live it's first year or two street/track... then eventually full track.