Jonny A

I have been looking for a 911 for the last year plus, and have driven lots of cars from the mid 70's to 964's. I have finally decided on a 964.

My only concern is the early nikasil cylinder with no head gasket oil leak issue on the 90-91 engines. I see the upgrade to the late style cylinder with revised sealing surface with a grove for the head seal from Porsche, and would like some feed back if I should keep my search to the 92-94 cars, or is this a small issue not worth worring about.

One day when it is time to rebuild the engine, I would like to add the ninemeister heads and want to make sure they will work on the earlier engine.

Thanks for all the imput.

Jonny A.

TR6

Most have had the head updates by now. If they have, I don't think its an issue. There may be some out there that don't though. Not sure how you confirm it without tearing into it other than service records.

sundog

I rebuilt mine, for the 3rd time, and it still doesn't have the head update. If put together correctly it does not leak.

Geoffrey

The cylinder to head sealing is only one of the considerations for an early car, and if you plan on rebuilding the engine anyway, it is a moot issue as you can upgrade. The other considerations worth mentioning are the lack of the later style shift console box so you cannot upgrade to the RS short shifter, rear twin piston cailpers, and the aluminum intake manifold.

And, don't forget that some of the 91 models have the updated engine.

1990-964

The considerations that Geoffery mentioned are not deal breakers. I did a simple mod to the shift console box and have been successfully running the RS short shifter. Upgrading the rear brakes is a common upgrade, which I have also done. As far as the aluminum intake goes it would not be too bad to update that as well since the plastic intake is fairly affordable and not too involved to change out. These points are well taken it is just that the early cars are plenty workable.

ilko

Hi Geoffrey, do you know which 91 cars have the updated engine? Mine's a late 91 (March 91 build) and I have a lot of the 92+ upgrades like DMF, flattened oil lines, steering stops, etc. that came standard on the car from the factory. I've always wondered if there is a way to tell.

Geoffrey

Ilko,

I don't know which 91s have the later components. I have seen a few so I know that somewhere along the 91 model line they were upgraded.

joey bagadonuts

I had a 91 C4 with plastic intake manifold, built Oct 90.


Ditto.

I've owned two pre-92's and have had no major issues because I asked a lot of questions before buying and gave each car a good once over. If you're not comfortable with your knowledge of 964's, then a good PPI is probably a wise investment. And don't be scared off by high-mileage cars. If they've had a top-end rebuild carried out by a reputable shop, they might represent an incredible bargain.

Generally speaking, it's not so much the model year which should guide your decision. Any car is a rolling time bomb if not properly maintained. Find one with a well-documented service history and confirmation that the engine is in good health, i.e. leakdown numbers, compression test, etc.

dfinnegan

The engine seal fix was done on engines with serial nos. after 62M06836, M64.01

The engine serial number is on the right hand side of the fan where it mounts to the engine.

My build date is 1990.09.19. I do not have the seal, but I do have the plastic instakes.

TR6

So, I guess I've learned something new... The early engines had a different intake than the later engines? Did the aluminum intake come on the early engines and what are the advantages/disadvantages of aluminum vs plastic? Any photos? -thanks

rodtds

That is why you see the price disparity from '90 to '91.

ilko

Here you go:



As far as advantages, I can only speculate that aluminum was replaced with plastic because, as a metal, it retains heat more so than plastic does. But that doesn't explain why the 993 comes with an aluminum intake. So I don't know the exact reason...

chancecasey

Plastic was used in the later engines because:

1. It's cheaper
2. It's lighter
3. It insulates the inside from ambient heat better
4. The inner surface is smoother and it flows better

You can usually find a set for $300 or so from dismantlers. Pretty expensive for a nominal performance gain, though, IMHO. This upgrade would be down a ways on the to-do list. I'm not tearing my intake down again to do it, but next time it is already torn down, maybe.

ZX3tuning

so is the oil leak issue extremely bad with the older version or is it just a constant leak issue like with the old 3.3 930s and such?

donoman

I did not notice a price disparity between these cars, how much is it and where is your data from if you don't mind my asking (just bought a '90)