Late model engine for 1983SC...?

Question

I want to update my 911 to a later 3.6 or 3.8L from the original 3.0

The 915 tranny has been rebuild, and the rest of the car is ready.


Thanks!

Answer 1

I say - Go for it! I know of some shops that do this regularly for about $10k. 964 and 993 engines are rock solid. True that you need to find a good one, but that's pretty easy. I assume when you speak of 3.8 that you mean an upgrade of the 3.6 engine. I know several that have done this and I would not recommend it - not the best bang for the buck. You would just replace the 3.6 Pistons and Cylinders with 3.8 ones from Mahle, for example. There are two ways to do it - either bore the case and go with the much bigger set. This is fairly expensive. The other way is to get the option with the same outer diameter as the 3.6 set, so they fit right into the case, but they have thinner walls. I don't really like either option. Where do you stop? Bigger camshaft, crankshaft, etc... The 3.6 engines have planty of power, particulary the variocam 993 engines (96-98).

Answer 2

Engine swaps to later aircooled engines are quite common, although they are not strictly simple procedures. The prime canidates would be engines from either a 964 or a 993 - either of the 3.6L units from these models would provide a nice jump in power for an SC.

The 3.8L 993RS engine would be possible too, but would be a much more expensive option (as these engines are rare, you would likely need to find a regular 993 engine, and then have it upgraded). The 996 and 997 engines would also be possible, however this is a much more complicated procedure since you would also be making a switch to water cooling.

The 964/993 engine is mostly a straight swap, though there are some custom parts needed as well as different exhaust. However, since this is a common swap, there are more than a few shops that have put together packages containing all the needed fabrications (which would be the biggest problem if you decided to go with one of the water cooled engines, you would need to do all the fabrication of custom parts yourself, or pay to have it done as a one off).

The real consideration here will be if such a swap is worth it, as the cost of the engine and parts alone will probably exceed the value a mint condition 911SC... and that's before you begin to deal with the issues that more power will bring (you will probably want to upgrade the brakes to handle the extra power, and may find your suspension also in need of upgrades, etc).

Also, since 964 and 993 engines are all at least 10 years old now, you will also need to be careful in selecting an engine transplant since it's possible it could have issues.

Answer 3

I'm not sure your 915 tranny is really up to a lot more power. You'd best make the transplant a sober one. And you won't have the hydraulic clutch either so you might end up with a very heavy pedal. Stay away from any C2 motor. 1990-91 or you'll be sorry.

Maybe an '88-89 engine would be just about right.