What's entailed in the 964 oil pump mod?

[Ho Hum 74]

Hi everyone.

I'm thinking of putting a 964 oil pump in my 2.7 rebuild but want to know what has to be done to the case. The machine shop who is cleaning my case and polishing my crank has never done this before. Is this a very straight forward and obvious mod?

Thanks
Tristan

[Britwrench]

When you rebuild a 2.7 there's a lot more to it than cleaning the case and polishing the crank. Read Wayne's book, take the case and crank to an experienced machine shop. This is not an engine to let someone learn on.

As far as your pump question, 911 oil pumps, in general, do not wear out or cause oil pressure problems. Take the pump apart and inspect it.
You didn't mention the year of the 2.7 but there are soem mandatory modifications required for the early version. You must have the correct technical information before working on this car. Pelican sells all the books you need.

[Ho Hum 74]

Thanks for the reply. I have the book and I'm well aware of the 2.7 issues. My case does not need the oil bypass mod done to it as it seems to be a later case with the mod incorporated.

It is not the first time that someone has told me that oil pumps don't fail that often but how can I be sure mine (1976 style) is ok?

I'm not sure if my pump is within spec and no one I talk to will test it for me.
Tristan

[HawgRyder]

Tristan...I am about to used the big turbo pump in my 2.0L...I will have to shave the bottom of the next main bearing block to get it in.
If you look at the case when apart...you will see the height of the bottom of the main saddles is not the same for all of them.
The mounting holes are the same...but the piece of main saddle is in the way of installing a bigger pump.
I believe to go to any of the later pumps the saddle is machined...but check the fit before ordering the cuts (both halves have to be cut).
Bob

[cstreit]

Tristan,

I think the oil pump check basically entails checking the backlash of the gears with a dial indicator. I think it's in Wayne's book, if not, e-mail me and I can find it for you.

[Ho Hum 74]

Yes Chris, Thanks. I have noticed a few scoring marks on the gears so not sure if this affects performance in any way. I think you saw my pump but I can try and measure the backlash as well. Are you still away this weekend?

Cheers,
Tristan

[cstreit]

Tristan,

Yes, going to the MCSCC banquet. (More bragging as to why later) but I'm around this week and early next week. I may be around Sunday if I can't shake this cold, otherwise we're going skiiing on Sun.

Give me a jingle.

[anh911]

Clearance between the gears and the gears and body are critical. If there's deep scoring on the gears or pump body it should be checked more thoroughly.

I don't agree that 911 pumps don't go bad, I've seen many.