Getting engine rebuilt - what do I need to watch out for and ask?
 

Hey everyone, I’m Neil. Proud newish owner of a 81sc that has a recently discovered broken headstud, and car is at the shop getting ready to do a rebuild. 135k on clock and solid records, just luck or the draw when I purchased her I suppose.

I’m reading a researching as much as possible and know my car is in very capable hands, but feel a bit overwhelmed with such a project and its potential spiraling expenses.

Engine performance aside, what are the other items I should consider ‘while I’m in there”? Clutch… 1st, 2nd gear synchros….things like that.

Will update as we get going!http://forums.pelicanparts.com/uploa...1687378845.jpg

How much do you wanna spend? This could easily turn into a $40,000 "head stud fix."

Unless you have reason to do a full rebuild, don't open the case. That will add $5000 to the tab. The bottom ends of SC engines are very durable. 135Kmi is not halfway through its life. Replace the lower Dilavar studs on both sides. Freshen up the valve guides and seats. Put it back together. Resist the urge...

Otherwise, your costs will spiral.

Your shop probably wants to do a full rebuild, because they want to guarantee their work and don't want you coming back with other problems later. That's safe for them, but expensive for you (ballpark $20-30K).

If you do venture down the slippery slope, then consider a different cam ($1000) higher compression pistons, or a 3.2 drop-in piston/cylnder set ($5000), and whatever else your wallet can afford.

Oh man,

https://forums.pelicanparts.com/porsche-911-technical-forum/1142039-what-not-do-when-building-engine.html

I started planning to do my headstuds when I found one broken one during a spark plug change.

A year passed and I did a valve adjustment, I found one more broken head stud.

It took me another year before I pulled the motor to do the top end and studs. I found one more broken.

Plenty of guys will tell you it’s ok to wait. I mostly agree. You won’t do harm driving the car. But if you are prepared to do it now, go for it.

Clutch, gaskets and seals. Likely a top end/valve job

Agree with others. Don’t split the case. Your 3.0 is good for another 100k maybe double that before it needs any major work.

neil -- you say above that you " know my car is in very capable hands" -- has your mechanic had a chance to analyze your car? If so, what's he recommending at this juncture?

Carrera timing chain tensioners

Similar here, found the headstud when adjusting the valves and decided to get the summer out of her and tackle the work in winter. Well, after a nice day of driving a few hours she started to smoke, and bad. So that’s when decided to get trucked over.

I hear you on the case and solid advice I will follow!

No, I haven’t gotten the advice yet as car is in this small shop’s rotation (and I’m the new guy! Lol) and expect and update soon after it’s dropped and inspected. We will be discussing work plans soon and why I’m trying to get ahead of it a little.

I can’t wait till I’m able to update on what we find. The wait is killing me

What stud(s) are broken? If interior studs, I would be less concerned than if they are on the outer edges. If interior studs, the heads are supported by the adjacent studs (via the cam housings). If outer studs, I'd be inclined to fix them sooner rather than later, and/or drive it conservatively until the studs are fixed.

i did mine myself...

it was basically a top end and i did not split the case. i did not even replace the clutch as my measurements indicated i could go another 42 years before i hit the wear limit at my current rate.

But i did do the first and second synchro , dog teeth and brake bands, glad i did as that was the biggest drivability change after i was done.
the rest was really just in gaskets and wear items, ramps, chains, etc. The machine shop said my heads were damn hear perfect and just cleaned them up and replaced the seals. Other things i did while engine was out were heater boxes refurb, cv joints, replaced engine sound pad... all stuff just easier with the engine out.

The one thing i did not do that i wish i had was fuel lines that run from the front of the car to the back. Just for peace of mind.

Whatever you ultimately decide to do, make sure you and the shop are in lockstep about exactly what they are to do. As you seem to be a new-ish 911 owner, do your homework on the shop and talk to people who have used that shop. There are shops that are good technicians, but have questionable business tactics.

It seems best to know what you want, and discuss it with your shop.

Do you want a hopped up high maintenance engine?
Do you want a basically stock motor, improved with 40 years of knowledge?
Do you want something in the middle?

Neil... You'd do well to post a new thread asking if anyone knows the shop that you're planning your rebuild with. Doing so inside this thread would burry it to some degree. This is suggested with all due respect to you "knowing your car is in capable hands."

Example of a Porsche shop that some knew without genuinely knowing is MotorMeister. That company screwed any number of Porsche owners. Search Pelican and much (if not all) of the customer reports on MM is bad. This forum is a great resource to qualify whomever you are intending to use.

Nice Targa! Best to you with the project ahead!

Do this, it is excellent advice. You might also ask about the realistic, expected timeline for your rebuild.

Thanks everyone. I’m based in New England and have the car with Mark Nader at Exotech. Local racer, DE instructor and certifies cars for track days. His shop reminds me of the ones I used to hang out in growing up and has an old school no b.s. feel to it.

My goals are sporty and easily maintained. Some DE days and progress to some track use. Was able to score a set of SSI’s off the used parts forum and ordered an M&K 2/2 that will be delivered in a week or two. Performance aspirations after that is going to come down to cost candidly.

Fuel lines sound like a good ideas. And somone was just selling sound pads on the parts forum too! Have to research more on the transmission opportunities and costs. I def see some room for improvement.

Appreciate all the replies, I am indeed a newish owner. Had a 912 in my late teens (a long time ago!) and have been dreaming of another once since. The need for a rebuild so soon is a bummer but I’m choosing to look at it as my opportunity to get her all sorted out and make it mine.

Mark is cool, and knows what he is doing.
He has my 997 engine in now.

Rich

I was at Marks shop this winter getting my heads, conrods, etc done. All I saw were air cooled sixes in his shop. My engine is back together and running great so far (150 miles).

I just had my 81 SC done for the exact same reasons as you - broken head studs. My mechanic actually found 4 studs broken. If you haven't already done it, the Carrera tensioners mentioned is not a bad idea. I had these already. I also had my clutch replaced. Fuel lines, injectors checked, and worn vacuum lines replaced as well. Heads machined. Camshafts checked and reground. Piston rings replaced and pistons checked. Timing chain and rails replaced. My engine tins were powder-coated, replating of all bolts and hardware. Truth is, your guy is probably doing most of this stuff anyways. Most of the stuff is relatively minor, but the big hit will be refinishing the heads and new pistons if you need it. I specifically asked for a "partial restoration to stock" using Genuine Porsche parts for anything significant or visible. I did have him also replace my shifter and steering wheel bushings and did some cosmetic items. I've got a few hundred miles since the top end and running great. Good luck.

If budget is a concern...
 

Once you find a trustworthy shop, it might be good to step back a bit and have "him" give the car a good once over to make sure nothing is getting close to failing, the usual PPI stuff, check CVs, bearings, shocks, bushings, electrics, tires, check for oil leaks, then run a leak down test to help define the rebuild.
There will always be unknowns, like clutch, cracks, worn out ancillaries, e.g. alternator, starter, hoses, worn electrical harness.
Have a good bit of spare cash, to cover discovered needs, (or wants :-)
You are for sure going to use some of it.

Good Luck,
chris