Early 911 Engine build

yoda · Post by **yoda** » Mon Nov 29, 2010 3:33 pm

Hi

If I were to have an early 911 engine built / rebuilt, is there a sensible list of do's and don'ts that I should be thinking about? It would be a 2.7 RS Spec engine on 7R cases and MFI.

The sort of thing I am thinking of is shuffle pinning - sounds very sensible for early engines but depending on who you talk to, some engine builders say they would do it others say they wouldn't (as its not to original Porsche spec).

Other things like use of later hydraulic tensioners seems more universal.

Is there a good list of engine build choices with some pros and cons?

Any help or advice gratefully received.

Regards

Nick Moss · Post by **Nick Moss** » Mon Nov 29, 2010 4:35 pm

some engine builders say they would do it others say they wouldn't (as its not to original Porsche spec).

No, it's not to original spec, but then Porsche never intended their engines to be still running 37 years later! Get the cases checked for alignment and line bored if required, have the cases modified for the oil bypass and fit a later SC type oil pump. I would also have the case shuffle pinned and boat tailed, as well as having the head stud threads timecerted and use ARP studs.
If the Barrel and pistons need replacing I would go to 2.8 with higher compression. I woulsd also balance the crank assembly. That lot will give you a very responsive 240 bhp on SSIs

davidppp · Post by **davidppp** » Mon Nov 29, 2010 5:14 pm

Hello, yoda.

My advice is to start with an SC not a 7R.

Good pistons cams and MFI and you will have an unbreakable 260plus BHP with loadsa torque.
Only about 25kg heavier..

David

yoda · Post by **yoda** » Mon Nov 29, 2010 9:00 pm

Thanks both for you replies.

To put my question in context, it is a complete existing engine that has faulty cases and will be rebuilt in to replacement 7R cases that come with it. Existing parts would be checked and used where possible and my aim would be reliable power and longevity rather than max power. So far on the list for consideration:

1. check cases for alignment and line bore if required
2. modify cases for the oil bypass
3. fit a later SC type oil pump
4. shuffle pin case
5. boat tail case
6. head stud threads timecerted and use ARP studs
7. balance the crank assembly

I am guessing all of the above would aid reliability.

Thanks again.

Nick Moss · Post by **Nick Moss** » Tue Nov 30, 2010 7:47 am

5 and 7 add power, the rest add reliability