Advice on Scope of Rebuild

[The Watson]

Greetings:

My "new" 77 911S sat in a garage for 25 years but was supposedly rebuilt about 1,500 miles before that. Zero info other than 3rd hand word of mouth on that. I'd welcome some feedback on the plan from here. My goal is to keep the 2.7 and do a fun lightly modded car (i.e. lose some weight, increase performance but without going all-out with twin-plug, webers, high-compression, etc).

Plan:
- pull engine and trans and inspect wear
- remove a/c, thermal reactors, smog pump
- install case savers
- replace all seals, etc
- go to a more sporty cam profile (maybe 964?)
- SSI's or other free breathing exhaust system
- replace 5-blade fan with 11
- re-install CIS after good tune up

I am proceeding by using Wayne's books and have not done a rebuild previously, but I do have familiarity with the basic concepts and no problem digesting anything I have read so far.

What would your plan be at this stage? What am I missing? The inside condition of motor is a huge unknown, and so I may be replacing more (cylinders, etc).

Here are a couple of pics so you see what I am dealing with. In the end it will be gorgeous, so some vision is required!

[The Watson]

[Flat6pac]

Wow, speaking about having all the heat producing items in place. Evem by the late 70 all the fans and thermals had been removed and replaced with 11 blade fans and tube down headers.
Bruce

[The Watson]

Just lucky I guess! This was a California car so there was no option for removing all that junk and passing CA Smog Testing. Except the A/C of course.

[Steve@Rennsport]

Originally Posted by The Watson

Greetings:

My "new" 77 911S sat in a garage for 25 years but was supposedly rebuilt about 1,500 miles before that. Zero info other than 3rd hand word of mouth on that. I'd welcome some feedback on the plan from here. My goal is to keep the 2.7 and do a fun lightly modded car (i.e. lose some weight, increase performance but without going all-out with twin-plug, webers, high-compression, etc).

Plan:
- pull engine and trans and inspect wear
- remove a/c, thermal reactors, smog pump
- install case savers
- replace all seals, etc
- go to a more sporty cam profile (maybe 964?)
- SSI's or other free breathing exhaust system
- replace 5-blade fan with 11
- re-install CIS after good tune up

Chuck,

When its apart for case savers, you need to have the case half parting surfaces machined flat and then the main saddles bored back to standard. This is SOP on ALL mag cases due to distortion after releasing the case bolt torque.

Use an SC profile, not the 964 one.

There are hundreds more details, however this is a good start toward a reliable engine.

[The Watson]

Thanks for that info Steve. I made reference to the 964 CAM based on this article and others' references to it, which states that it happens to work well with the CIS system. What would the argument be for using an SC profile?

Pelican Technical Article: Extracting Power from CIS 911s...

[The Watson]

OK, that is weird. I just started re-reading that article, and it quotes you, Steve, with the idea. Getting a little circular! So now it's really confusing!

[Lapkritis]

I imagine I'm not alone but I get really excited seeing a project with potential. I dare say they're more appealing than a completely done car to me as what you have is essentially a blank canvas to do with as you please. Enjoy the project - if the engine was just serviced then I might be tempted to avoid a case split pending the outcome of a thorough visual inspection once you're down to just the case.

[tharbert]

With a plan like that, it sounds like the game is afoot. It will be interesting to watch as you dig into this. I hope, for your sake, the case is already done and the p/c's intact. With a 2.7, the slippery slope is very steep and $pendy. BTW, you have plenty of time to decide on a cam.

[Steve@Rennsport]

Originally Posted by The Watson

Thanks for that info Steve. I made reference to the 964 CAM based on this article and others' references to it, which states that it happens to work well with the CIS system. What would the argument be for using an SC profile?

Pelican Technical Article: Extracting Power from CIS 911s...

Hi Chuck,

No confusion on my part.

SC cams have more low-end torque than 964 cams and given the modest displacement as well as stock gearing, the throttle response and net performance is better with SC cams in a 2.7.

3.2 engines, OTOH, run very well with 964 cams simply due to their larger displacement.

[The Watson]

Thanks for clarifying that Steve. And I assume you would move up the compression as well with a JE piston set?

Some bad news today as well, got the car on the lift and found that the tow loops appear to have pulled out the front suspension mounts from the body. One is torn and the other is bent Appears to be the work of any over-jealous transporter ratcheting down the straps too tight for the trip across the county. Wasn't anticipating this:

[Lapkritis]

The first and surely not the last of darn old scope creep. That does appear to be the result of an improperly secured load. Every bump in the road would be going through those points in the chassis not intended to bear the weight of the car. Sorry to see this - have you begun the process of inquiry with the shipper for the damages?

[The Watson]

Well, after a few hours over a few days of disconnecting parts, the engine came out today. Even with a 4-post lift and a engine hoist there were still a few head-scratching moments. I decided to go with Wayne D's version of taking out only the engine first and leaving the gearbox as I was unsure of the weight and balance requirement for doing both at the same time. This went fine. As you see in the pic, we used the engine hoist to lift the car above the engine so we could slide it out. The (soon to be discarded) bumper shocks made for good latch points. Overall a gratifying process and one that could be done in 1/3 the time if ever done again (knock on wood).






I guess now it's time for some teardown. And cleaning. And cleaning. And cleaning.

[The Watson]

So....teardown is fun. Made some good progress yesterday. And the good news is, despite 130K miles, thermal reactors, 5-blade fan, air conditioning and a smog pump......no broken head studs! Although one looks like it will be a bear to get out as the barrel nut has little bite since it is almost all the way onto the stud. Also, the crank does not budge yet as one of the cylinders looks to have corroded internally - not sure yet and not forcing anything. Cams come out next time I can get into the shop. Any thoughts or observations appreciated. A few pics:

[JJ 911SC]

Originally Posted by The Watson

... I am proceeding by using Wayne's books...

Here are some updates and corrections to the book: How to Rebuild and Modify your Porsche 911 Engine: Corrections & Updates

[E Sully]

I wish you well on your project. Hopefully it will not be too bad internally. A new suspension pan and fan are definitely on the list. I have heard SSI exhaust are available again, one of the first things I bought for mine. Chain tensioners are another area to look into. Old style with safety collars, or Carrera oil fed style.