CrookedRacer

I have a new-to-me used oil pump for this engine because the old one made some bearing sausage... and I guess I just can't catch a break on this rebuild!

The problem: My new oil pump has bolt bosses that are all the same height, whereas the old one had one hole that was reduced in height, which allowed the timing belt tensioner to just clear it.

Of course, the tensioner does NOT clear the oil pump I installed. :-(

It looks to me like I could grind down the right-hand boss to the same height as the old oil pump had... plus it should have another benefit: it would make all my oil pump's mounting bolts the correct length! (one is currently too short and I couldn't figure out why!)




The oil pump now on the engine has two bosses that are the same height.



The housing that came off the car has one that's a little shorter. It needs to be, so the timing belt tensioner can clear it and bolt down to the block properly.



You can see the bolt is too high and fouls the tensioner where the empty bolt hole is.



another view of the interference.



A comparison of the two housings.


Now, I'm worried that the oil pump I installed is incompatible with my 1988 NA engine. Any idea if there could be much difference on the inside?

Thanks!

CrookedRacer

The oil pump that came with the engine is 944 107 111 "1 R" (additional code after the part number in a little oval)

The oil pump I just painstakingly refurbished and attached to the engine is 944 107 104 "9 R" (same oval space to the right of the part number)

V2Rocket

Why change oil pump even after a bearing death?
944 oil pump is quite robust.

Looks like you got an early model pump made for the manual tensioner.

CrookedRacer

I took it off to clean everything and this is what I found inside. This is going to be a race engine so I decided I would get something a little less... marred.

CrookedRacer

I can make this housing work as long as the insides will work for my block.

V2Rocket

Hmm, that one has seen better days
Probably fine to use in a street motor though.
Alternatively...could you grind the back of the tensioner?

Van

Make the bolt boss shorter. That oil pump must be for an early car with the manual tensioner.

Voith

What happened to those gears? Never seen so damaged pump.

tempest411

Others will know more than I, but I have seen differences in the channel the oil flows through which mates to the block. There are slightly different shapes across the production run. On my own block I was careful to get a pump for the year of production of my block, and even then, there were a couple different ones depending upon whether it was a turbo or NA (as I recall). If the ONLY difference is the height of the boss on the pump, that's a super easy machining job. Just get a slitting saw and even use it on your drill press if you don't have a small mill.

CrookedRacer

Thanks everyone! I'm going to just get the correct pump for my block. Simple solution.

I don't want to put this engine in only to find I can't make oil pressure.

If anyone needs a nicely rebuilt oil pump including brand new class-12.9 hex head screws for the housing insert...

Adonay

Actually i have 3 different pumps here and i have never seen any damage to a 944 pump before exception being the sleeve gear. Makes me want to check them all again

CrookedRacer

You can read the entire history of my life with this car on GRM:
http://grassrootsmotorsports.com/for.../105890/page1/

Or watch the video where the #2 bearing disintegrated:
Skip the lap to about 2:30 on this video.