Claus Groth

I'm starting to reassemble the track engine and found that the girdle that
holds the crankshaft in sticks out toward the front of the engine .014 (.36
mm) further than the block. The workshop Manual instructs to tap the girdle
into alignment but there is a bushing around one of the bolts that aligns
the girdle and block and the fit is so tight that there is no movement. The
WS manual also states to use an oil stone to hone any surface imperfection
between the parts since the oil pump must fit perfectly over both surfaces,
using Loctite 574 to seal the pump, same as sealing the girdle.

My first thought was that a girdle from another engine was installed since
Porsche states that the block, girdle and both balance shaft housings must
remain a set. They are numbered and mine all have the same number.

No wonder that I always had a leak at the front! How could Porsche have
built this engine? How could a prominent engine builder and tuner have
rebuilt this engine for the PO? I don't know.

All I can think to do now is to machine the front surface of the girdle on
the milling machine and polish it. Any thoughts or suggestions?

mark944turbo

What I do usually is tighten down the oil pump first, then the girdle. Usually I leave the pump dry and take it off again once I have a few bolts tight on the girdle.

Definately machine it down to match if there is no other way to get them even, but usually there is a small amount of free play which is enough to compensate.

HTH

Claus Groth

There is no free play in this one. I can't move it with a plastic hammer and the bushing and hole measure to a tight fit. I can't bring myself to goop up the gap and put the oil pump on. .014 is a huge gap.

mark944turbo

Yes, I don't think that the Loctite will fill such a big gap. Not worth the risk.

I would try tightening down the oil pump then some girdle bolts as a last effort before machining, if it works it will save some time. The machining is probably better though, as it is probably good to have as little built in stress as possible in these areas.

Oddjob

0.014 is a pretty small lip, you should be able to oil stone it flat very easily - no need to have it machined. The first time I reinstalled a girdle, it was 0.09" from flush. I ended up pulling it off again, resetting, pounded the hell out of it, and got down to below 0.03" and stoned it from there.

This is a common/expected procedure when rebuilding 944 engines - thats why its even discussed in the manual. The manual tells you to give the girdle a preliminary torque to hold it in place while hitting with a plastic/rubber hammer. Did you try this?

I have seen several others recommend placing the girdle in the freezer to get some slight thermal contraction in the part. You could try this (I have also), but I have some concern about the condensation that forms on the mating surface (gets moisture in the loctite) and on the main bearings (you dont want any water droplets in the assembly lube on the bearing surfaces). If youre working in a cool/dry garage it might not be a problem - but I did it in the middle of a hot hummid summer day and thought the condensation was problematic.

Mike C.

I had a good .020" step when I did mine. I couldn't beat it down and I didn't have a milling machine so I made a brass shim shaped to the oil pump mating surface, loctited both sides and it's been good for 150K miles now. I would suggest milling it it you can.

Claus Groth

Mike, that was a good idea. Shimming should have been one of my options but I didn't think of that approach.

How did Porsche assemble and ship something like that? Unbelieveable!

I machined .013 from the surface today and lapped the last .001 with the oilstone. I then installed the pump, torqued the screws and one stripped! Great! Disassembled and retaped all holes. The hole was deep enough, and I had a slightly longer screw, that I didn't have to Heli-Coil. So it is finally installed and pistons are next.

Thank you all for your advice.

Mike C.

I also wondered how the engine was assembled with such a step. However, on mine (IIRC), there was not any noticeable step when I first pulled off the oil pump. I'm thinking there may be some kind of material aging and/or stress relaxation that takes place and when you unbolt the girdle it expands... I don't know.... But it was obvious that even if you could seal a gap like that with loctite, bolting the oil pump over a step would tend to bend it, which I think would result in binding. I'm glad you didn't ignore it.

theedge

Freeze it in the freezer overnight in a plastic bag thats well sealed. Quickly rip it out of the bag and put the loctite on its mating surface, throw it on, torque lightly, wack with a hammer if needed. Might solve it, since you have a pretty small gap.

Oddjob

They didnt. When the blocks were originally assembled, the parts were machined flush. Its a cast aluminum part, not machined cold drawn steel. There is quite a bit of flex and movement in the part after disassembly. Unfortunately it wont go back together the same as it came apart.

Spoke to a couple engine builders on this. One local shop that builds a lot of 944 engines for club race cars, said they have never seen a 944 block that did not need to be oil stoned flush.