soofle616

The title says it all. I'm new here despite having owned my '78 SC for somewhere around 10 years now. My dad bought it about 20 years ago from the original owner with a mere 36k on the clock and in very good condition but stopped driving it and after I threatened on multiple occasions to steal the keys and take it home with me if he didn't get it out of the garage once in a while he finally relented and handed them to me. In the time we've owned it another 40k have come and gone with the odd hiccup here and there but mostly trouble free. Earlier this year though, I decided to have the oil analyzed and the report came back with very troubling amounts of bearing material. Not long after that I got into the engine to replace the lower valve covers hoping to tighten up some oil leaks (and adjust the valves while I was in there) when I found three broken head studs on the right bank. I still don't know for sure what the status of the left bank is but it almost doesn't matter. Between the wear indicated by the oil sample and the broken head studs I know about I decided it was time to tackle a rebuild.

Needless to say I am absolutely TERRIFIED to get into this engine. I consider myself a very accomplished wrench monkey and have been building/rebuilding bikes for years now including some smaller 2-stroke engine rebuilds but I have never taken on a job like this. I do have a copy of Wayne Dempsey's book arriving later today to help guide me but I'm sure I will be scouring this site and/or posting lots and lots of questions so hopefully you all can put up with me (don't worry, I know how the search function works).

Anyway, here's my girl, pre engine removal,

She's pretty close to stock other than the wing which was added by my dad a long way back, the body matched wheel centers, intake pop-off valve, and an upgraded head unit and speakers which, at 15ish years old are due for another update.

Along the road to rebuild I plan to update the cam chain tensioners but otherwise it will be a largely factory spec affair.

r911

you want a Bentley manual

go slow; check & recheck; document everything with both photos and with notes/tags attached

if you lack tools or skills for certain measurements, have a machinist check those things - you'll want an experienced old-911 machinist to do the heads anyway

and have fun

m42racer

Fear of the unknown is a powerful thing.

These engines are really simple. Nothing hard about them. Break the engine into sections. Intake, Exhaust, Cylinder heads and Cam assy, Pistons and Cylinders, Case with crank, Rods and oil pump. Tackle each part and it will become alot clearer.

DIY, is usually about disassembly and reassembly and maybe some cleaning. This is easy once you know and understand what to do. Repair work is typically sourced out.

PM me and I will give you some further direction to follow.

theiceman

I just finished my first rebuild also. I bet all your broken studs are lowers. It can. Be intimidating but take your time and you will be fine.
Get Wayne Dempsey engine rebuilding book. I have a Bentley but didn't need it as Wayne walks you through it step by step. .

race911

I did my first one when I was 18 (36 years ago now), having: 1. no previous hard mechanical experience, and 2. nothing in the way of the internet available. I will say some of the titans of 911 knowledge fully encouraged me--Bruce Anderson, Jerry Woods, and Jim Pasha to name the most famous.

You'll do fine, and answers to the routine and esoteric are only a post away.

soofle616

Thanks guys. My copy of wayne's book arrived yesterday and I've had a copy of the bentley manual for a long time so I think I have the basic references that I will need. My background is in engineering and design so I'm familiar with the various inspection methods and tools needed and have access to most of them so hopefully that will limit my need to outsourcing to things that require actual machining work. Found out yesterday that I bought the wrong engine stand adapter so I will be getting the right one soon so I can get started on this. Lesson definitely learned, I will stop trying to save money on cheaper alternatives and just get the right part/tool when needed.

theiceman

the only special tools i used were .

1. cam holding tool to take the cam nut off
2. built a tool for flywheel lock
3. used stromski tools for cam timing


other than that everything was fine. my only regret in the whole project was not replacing the rocker shafts. they are relatively cheap and can save so many headaches when used along with rsr seals.

one of the big debates you will have with yourself will be what to replace the suds with . I replaced all my lowers with steel and am comfortable with that decision.

500

I was in a similar situation to you…

I did a comprehensive re-build on my ’85 (split the case) as my first re-build. It has run perfectly from day one (three years ago) and is still absolutely dry underneath. If I can do it, anyone can.

Several thoughts:

1) Wayne’s book is a great resource, but not everything he does is recommended by others. Some of his sealant applications are different, and his recommendation to re-use the old nose bearing etc. were amongst the items I did not follow. There are some knowledgeable people on here that can provide recommendations. I would also start following the Pelican Parts 911 engine rebuild forum

2) In that aforementioned forum, search the “Henry Schmidt case sealing method” that is what I used and results were perfect

3) Buy or borrow the correct special tool in every instance

4) Err on the side of caution… better to spend more money replacing parts that are on the edge for example. If you feel you are slightly cutting a corner, DON’T!

5) Stock spec is a very good choice for a first re-build, but you can still address known weak spots (I used ARP rod bolts, Supertech head studs for example)

6) Be highly organized at all stages, don’t rush anything. More than one person had to “go back into” their engine to address a pesky leak or so because they were not as careful as needed

7) Don’t ignore the ancillaries: Sensors, hoses etc. You may want to consider if the AFM needs to be re-built (EDIT: Sorry, just realized you are an SC, no AFM, but lots of other ancillary items to consider anyway) and definitely validate the air-fuel ratio after the engine is running again…

soofle616

The debate on which head studs to use was fairly short. While I could argue convincingly that 38 years and 70k miles is enough to keep the car running for the rest of my driving life, the kind of money I'm already expecting to spend leads me to "go big or go home" so I'll be going with something a bit better than stock for the studs and rod bolts. As for reusing bearings, just the thought of it makes me mildly ill. Basically any wear item that comes out of the engine during the rebuild is getting replaced. Valve guides/seals, gaskets, hoses, etc.

Ill definitely check out the case sealing method mentioned as that's one of many items on my "really really hope I don't screw it up" list.

theiceman

so you going with Dilivar 993 ? or Henrys supertec studs ? the debate continues over on the Pelican engine building forum

sithot

I always like to see "head studs" replaced in ads for SC's and Carrera models if I'm "shopping". It's not a matter of if but when.

Head studs are the achilles the since the beginning. You're dealing with a 3.0 aluminum case which is a tank. Likely no time-serts necessary as they didn't usually pull (like a magnesium case). Getting the old ones out isn't daunting if you take it slow.

Bruce Anderson's book would be one to have as well as Wayne's book.

The machine shop can make you look like a hero so pick wisely. That's the hardest part imho. If all the puzzle pieces go back together correctly it's more fun.

Take your time.

r911

piece of cake - go slow; act like an engineer; no problems

r911

sealant samples

soofle616

Funny you bring that up. One of the bikes I'm working one requires loctite 574 for the breather elbow in the rear cylinder head. I've been debating if it was worth spending the 15+ bucks for a tube when all i need is a tiny drop to seal the threads. As I started looking into the rebuild for this engine I discovered I needed the same stuff so I will be getting a tube.

And to answer your question iceman, I'll be going with supertech or similar just for peace of mind.

theiceman

Henry does good stuff no doubt. If you are ordering that from him get his sealant kit. Everything you need to seal the engine with no leaks.
You can use his stuff on your bike too

I used yamabond4 and it was outstanding stuff