SC engine rebuild

I'm still blowing hot and cold over rebuilding my own engine.

I've read everything I can find about this and am still unsure of some things:

1, People make out this is a really expensive exercise. I've done some costings and, assuming I just need the usual things like rings, bearings, gaskets, valves/guides and studs, the cost shouldn't exceed £1500, which seems acceptable.

2, Is it really hard to do a bottom-end rebuild? At 130,000miles I'm loathe to just do the top end.

3, Bruce Anderson's book gives an horrific list of measurements that need to be taken when the engine is stripped. Are all these really necessary?

4, Should I do it or should I not???

Any comments much appreciated.

Cheers

Phil

Philsy,

I had my SC engine rebuilt by a very good local Porsche engine man. The amount of work (measuring, grinding, re-measuring, ETC..) was amazing. It took him a good 40 - 60 Hours to compleat the rebuild. I would not attempt the job for a few reasons. 1) It has to be done to exact specs. 2)You will need many special tools (big money) to do the job right. 3) The risk of messing it up is far to great. This from someone that is on a pit crew for a local dragracing team. I think the tools alone will cost nearly as much as the labor to have someone do it would cost. I would not skip the bottom end rebuild! It really must be done while the engine is out for the top end job. I would bet that the #8 nose bearing is going bad on a car with that many miles. Also, after a rebuild, the CSI injection usually needs to be re adjusted (a feat in it self). IMHO.

Phil,

I don't really think a top-end rebuild is out of the question, with that kind of mileage, and Bruce Anderson seems to agree. I would suggest replacing the bottom row of Dilivar studs as a precaution, though! And, even including the price of tools, the cost of a top-end rebuild could be economical, as well as rewarding ... I guess it depends on your level of competence with tools and following precise instructions. And, I would recommend purchase of both sets offactory service manuals before you decide, because if they don't look right (and logical) to you, maybe you don't need to start the rebuild. You might want to consider going to one of Bruce Anderson's engine schools, as I am quite sure that experience would give you the final answers you seek!

Even after Bruce Anderson's, school, tool and parts purchase, I think you could come out ahead ... not to mention, be prepared for the future total engine rebuild with all of the confidence to do that one, too!

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Warren Hall
1973 911S Targa

Philsy
At last a uk rebuild! go for it. Will follow with interest if you go ahead as no doubt mine will need the same soon

Bruce 83sc

Umm, all food for thought.

How about stripping the engine, taking the components to a specialist for checking and reconditioning and then reassembling myself?

Skill level? Well, I've rebuilt a number of engines, the most complex being a Rover V8, so I'm reasonably confident in that respect.

Bruce, where are you? Maybe we could join forces? :-)

Philsy, I talked to owner of local Porsche shop last week about rebuilding my 83 SC. He quoted tops $6500.00. He also encouraged me to do it myself. He said the 911 engine is the most mechanic friendly engine he knows. I did the top end of my 944 (broken belt) and it was a pleasure. The only sweaty part was retiming the cam. Old carpenter's saying....measure twice, cut once. As far as the 911, when the time comes I may give it a go. The machine shop that did the head work on the 44 could handle all the real work and I could do the assembly. Go for it! It will add years to your life, your sight will improve and the hair on your head will never fall out. Well....Maybe your 911 will feel younger. Good luck.

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Robert Stoll
83 SC
83 944

Philsy, i was in the same predicament. Just bite the bullet and do it. It's not as bad as people make out, just make sure you check eveything is in spec before putting it back together. It a great learning experience. Check out

http://users.ev1.net/~davmanku/porsche/carrera.html

[This message has been edited by beetos (edited 12-01-2000).]

Hi Beetos

Your site looks really useful - I'll have a good look tonight.

Thanks!

I'm in the exact same boat you are.
I plan on doing exactlt what you mentioned...
(teardown and clean it myself, then take it to a good wrench for proper reassembly)
I want to work on it myself but there are certain areas best left to a pro. I'll get to learn alot and save some money too.

Best of luck.

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Leland Pate

___79 SC Targa

Think about using 964 cams....I did, really woke up the car.....

philsy
been christmas shopping in southampton since earlier post, this local?

bruce 83 sc

Bruce

Kind of, I was brought up in West End and my parents still live there. However, I've moved to Oxfordshire. Still down in Hampshire quite often, though.

[This message has been edited by Philsy (edited 12-01-2000).]

Hi Beetos

Just read thro your site at http://users.ev1.net/~davmanku/porsche/carrera.html and found it really interesting - thanks. Can't believe you did it all without a stand!

I feel much more confident about tackling the job myself now.

Just one thing - not too sure about those shiny wheels!

I've done it --- in fact it was the first engine I had ever torn apart. Did everything myself except putting the new phospher bronze valve guides in and a line-bore. Didn't do a lot of micro-measuring of much of anything. How could this have possibly been successful? --- I had the factory manual and followed it to the letter. Got it all back together and it ran like a champ... so it can be done --- but if you blow it up then I'll deny, deny, deny... I just love the edit feature in these forums --- I can deny I ever said it!!!

I wonder about this too. Just how complex are these rebuilds? I was looking at the valve guide replacement procedure. Now, on an ordinary car you press out the old one, press in the new one and, well that's it, pretty much.

On a Porsche, you drill material from the neck of the guide first. The valve of course enters the head at an angle. Then you press out the remains of the old guide. I don't recall whether the head is resurfaced here, probably not, but then after the new guide is pressed in, you bore it out to fit the valve stem.

And at the same angle, the valve seats are a 3-angle grind. Tricky even for machinists.

Having said all that, there is no doubt in my mind that you should remove the engine and take it apart. Bolting it back together and putting it back into the car , you can also handle and these will save you many dollars alone. You'll pay for parts and machine work. Machinists who do not work on Porsches every day should probably not be chosen to do your work.

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'83 SC