Advice needed (3.2 rebuild content)

[DLK]

Hi all,

I own a 1987 G50 3.2 targa that came from the US. The car is in a very good condition and the engine runs fine. It does however have 220K miles on the odometer.

After importing the car into Europe I changed the Kat for a normal OEM pre-muffler and kept the lambdasonde. After this change I bought a Steve Wong chip and the car feels a lot more alive than it did before these changes.

Now I am toying with the idea to rebuild the engine. because;

1) It losses a bit of oil when it is parked (maybe 50ml over the course of three months). I suspect the oil cooler is leaking and there might be some other leaks (oil pressure sender etc)

2) I have all the maintenance history with the car and the engine still is the original engine and was never rebuild. Not even a top end rebuild. With 220K miles on the clock it might be time to rebuild.

3) My Porsche specialist allows me to work in their workshop. I can remove the engine on their premises and I can disassemble, clean and build up the engine in their workshop. (a friend of mine owns the shop)

4) I can get a set of pistons and cilinders for the euro 3.2 i.e. the higher compression set.

5) I like clean things. This gives me the opportunity to clean the engine bay, renew the sound deadening material in there. Renew the fuel lines etc. And I get the chance to clean the engine.

What kind of shopping list am I looking at? Would you recommend rebuilding it now that there are no big issues or would you just keep on driving it?

Give me your thoughts.

[911 Rod]

This is the same scenario I had before my rebuild.
If I did it all over again I would have chosen a different route.
Drop engine and clean and clean more. Fix triangle of leak. Change out the sensors. Maybe pretty it up with painting the tin, valve covers and shroud. Put it back together.
Would have saved me a boatload of cash and not having my car for a year.
If it runs well, why mess with it?

[Trackrash]

If you don't have Wayne's book How to Rebuild and Modify 911 engines there is a lot of info there. It details all the parts needed and what to look for when the motor is apart.

If it was me, I would do a leakdown and document how much oil the motor burns, or uses, over a period of time. If the numbers are good I would just do a cleanup, reseal, and replace rubber hoses etc.

I would also check for broken head studs. This can be an issue with those motors. Worn valve guides can also be an issue.

Depending on your skill and time you are probably looking at up to a year to do this all your self, if a rebuild is in the works.

I'm guessing you have a fairly large budget as well. You might want to price a new set of pistons and cylinders before you start.

[996AE]

3.2 carrera head stud failure. Never heard that one. 2.7 and 3.0 sure but 3.2?

[DLK]

Thanks for your responses so far.

Did I mention that I can get the barrels and cilinders to build a high compression (euro) 3.2 engine virtually for free :-)

This does make it quite tempting to rebuild it.

I will look into the book some one mentioned, I will order a copy

[KTL]

Originally Posted by 996AE

3.2 carrera head stud failure. Never heard that one. 2.7 and 3.0 sure but 3.2?

Yes it happens on 3.2 Carrera head studs as well. The reason is the same old story. Lower studs are dilavar material and if the coating is compromised, corrosion can make them break. Found one on my '86 Carrera 3.2 last November

your opinion on head studs

And as Gordon mentioned, 3.2 engines are well known for valve guide wear. I knew my engine had worn guides long before I decided to rebuild it. However, your engine with 220K miles on it has probably gotten a cylinder head service for valve guides in the past. I'm not saying that ALL 3.2 engines have worn valve guides. But it is pretty common. Nearly every 3.2 engine in my local group of 911s has needed valve guide replacement over the nearly 20 years i've been involved with these cars.

If the engine doesn't have any major issues, I would use the shop resources you have via your friend to remove the engine and disassemble what's needed to fix oil leaks and clean it. You can eliminate nearly all the leaks coming from the engine w/out the need to actually rebuild it. I did a "top end" service on my former '87 Carrera this way and it worked out very well. Basically I just took off the heads and left everything else assembled. But I still could have cleaned it up very well even if I hadn't disassembled the engine down to the cylinders. You can get at most problem locations by removing the intake manifold and the exhaust system. Also check inside the valve covers within the dry areas of the camshaft housing. If it's wet with oil inside the dry areas, you know you have leaky rocker arm shaft bores. That type of leak can usually be fixed with the special flat o-rings (aka RSR shaft seals).

I also wouldn't let the lure of the Euro 3.2 piston & cylinders coerce you into doing a rebuild. The power gains from that bump in compression are minimal and it's really not a big improvement even if you can get the piston & cylinder set for free. You'd be better served by getting a set of 98mm or 100mm pistons and cylinders to get a displacement increase that will increase power & torque. But even that approach doesn't gain you a major amount of power. It's very hard to extract a lot more power out of these engines w/out spending a lot of money. Or just install a low boost turbo kit..........

It's a slippery slope once you start down that path of changing pistons & cylinders because then you start thinking about camshafts, exhaust system, intake modifications....... To get optimum results you have to do a lot of things together since the engine is a system of components. Can't just do one thing and leave out the others or else your results are assured of being compromised.

[mepstein]

Almost every original 3.2 that comes through our shop had a broken head stud(s) no matter what the mileage.
One of the guys once tried to do a top end on a 3.2 with original dilavar studs. They weren't broken at disassembly but a day after he tightened up the heads, they started pinging out ot the top. I actually saw one fly out of the head and drop a couple feet from the engine.

[996AE]

CA car zero rust undercarriage is amazingly good condition. Engine came apart with zero issues. Studs are in great shape and have original black coating on them.

700.00 for new studs its gonna be. Going with SuperTec.

[carrera79]

Originally Posted by mepstein

Almost every original 3.2 that comes through our shop had a broken head stud(s) no matter what the mileage.
One of the guys once tried to do a top end on a 3.2 with original dilavar studs. They weren't broken at disassembly but a day after he tightened up the heads, they started pinging out ot the top. I actually saw one fly out of the head and drop a couple feet from the engine.

I can confirm that

Last year I have done a top end rebuild on a 86 coming from San Diego.
110000 miles and oil consumption.
Replaced with EU cyl/pis and studs looked ok.
Closed the engine and the day after on stud broke 😡😡😡
Changed all studs 😩😩
Fred

[911 Rod]

I didn't have any broken studs on my 86 at 390,000 km when I did the rebuild.

[Mark Henry]

Sounds you just want stock, then that's all I'd do.
To swap the P&C's out you will have to calculate the new CR, deck and valve clearances.

Unless the 9.8 set is like new it may not be worth the extra work,