Oil Pump Advice - '83 930 Rebuild or Replace

dduclaux · 12-06-2006, 06:37 AM

I'm doing a complete rebuild of an 83 930 and I am considering my options with respect to the original oil pump. As a threshold matter, the case, crank, rods, etc. all measure to spec and the internal components (pistons, cylinders, cams, rockers, etc.) are all pristine which indicates the oil pump was doing its job perfectly. (the rebuild is the result of broken head studs.)

Does anyone have guidance on disassembling the oil pump to check for wear and tolerance on the internal components? Is that action necessary? Can the pump be tested for pressure and flow without disassembly? Is it a far better thing to just upgrade to a GT3 oil pump?

Any input or experience would be appreciated.

Thanks,
Duane Duclaux
Richmond, VA

afterburn 549 · 12-06-2006, 12:49 PM

I would suggest TBO...sort of, how many miles on it ?? 100,000 ok (maybe ) 200000 i would replace for sleep ezz .I dont know that they are failure prone...I do know it is the hart of the eng. We both know it is in a bummer of a place if you have to pull it later......

carmad · 12-06-2006, 01:27 PM

I had mine serviced by EBS Racing in Nevada. Had 67,000 miles on it, they said everything was in spec, and ported it for better flow.
No problems after 6000 miles and several track days.
It cost about $150, IIRC.

Mysterytrain · 12-06-2006, 05:14 PM

I went thru this a couple of years ago when my engine was rebuilt. I went with a new pump for piece of mind.

Walt Fricke · 12-06-2006, 11:37 PM

Hell - if it were mine I'd inspect it. Look very closely through the openings while rotating it. If I saw nothing nasty looking in the way of scrapes or dings or battle scars (especially on the edges of the teeth, where something could get caught between a tooth and the case), and the engine had fine oil pressure, I'd put it back in.

There really isn't anything to replace/rebuild, I think, on these. No bearings or bushings. This is the mighty "Turbo" pump, right? Large pressure section, large scavange section, short stubby splined tube connecting it to the IS shaft?

You can pour oil or some suitable fluid (kerosene?) in it and spin it by hand. Not much to learn other than yes, it will move the oil through. To test it you'd have to fabricate a lot of stuff, including something to spin it. Haven't heard of anyone doing that, but who knows.

But I'm cheap and a gambler - you said the engine's innards were just fine (so you are in there just in case to replace bearings, right?). This is a very good pump as a general matter. Why worry about this. Have buddies been filling your ears with tales of premature wear on 911 oil pumps? This is not an obvious thing to replace during a rebuild. Those bearings that looked OK, sure, replace them anyway. But a pump?

Walt

sand_man · 12-07-2006, 05:23 AM

Neil Harvey of Performance Developments rebuilt the oil pump in my '87. According to him it was well within spec. FWIW, I had no real catastrohic failures in my engine, when I decided to rebuild it at 42,000. It was mostly just to upgrade some things, and seal all the oil leaks.

eapcpa · 04:39 AM

You need a new one. Send me the old one I will pay for shipping. LOL

Inspect it, No obvious play in the shaft or damage to the internal gears, Run it and forgetaboutit!!

WydRyd · 12-07-2006, 07:10 PM

If you've done a complete teardown, it might be worth fitting bigger piston splash valves, for better piston cooling.

dduclaux · 12-08-2006, 11:35 AM

Thanks to everyone for their thoughts on this. I will post pictures of the rebuild for all to see and comment about all the things I am doing wrong.