85 3.2 Rebuild Questions

I am in the process of rebuilding (top end) my 85 3.2 engine with 135k miles. I have a few questions that I hope some of you guys(gals) can clear up.

1. I am having heads rebuilt with face surfacing, do I need to install thicker (.50 mm) cylinder base gaskets or stay with .25 mm stock?

2. Have Mahle Nikasil cylinders. Can I hone or de-glase and install new rings? If new rings are installed, what is the break-in procedure to get the rings to seat?

3. The engine does not have a gasket between the cylinder and the head. Is there a need to install one to ensure a good seal?

4. What is a good lubricant to use when putting engine back together?

This is my first 911 engine overhaul and I have good tips for this web site and have tried to answer questions when I can be of assistance. Thanks for providing this knowledge base..

I doubt that you would need thicker base gaskets unless your machine shop is taking a lot of material off of the top of the head.

The Nikasil cylinders should be able to be honed. These are the ones made by Mahle, and don't have the special coating on them.
Run the engine at 2000 RPM for 20 minutes. Take a stop-watch with you, because after 10 minutes, you'll swear it was 20. Then make sure that the car is running semi-lean. Running too rich will make the rings not seat properly. I also recommend running non-detergent oil - no synthetics! Change the oil every 100-200 miles when you drive it. Don't drive above 4000 RPM or so until after 500 miles.

Also go to a hilly spot and accelerate up the hill, and then let off of the gas on the way down, letting the engine slow the car (engine braking). This should create a bit of back pressure on the cylinders that should help to seat the rings. Make sure that you don't break a ring when installing...

I use the German moly lube that comes in the blue tube (I forget the brand off the top of my head? Liqui-moly?)

Interesting. In 1984, Porsche eliminated the head gasket. I haven't rebuilt a 3.2 yet, so I didn't realize that. My '82SC engine has a cylinder-to-head gasket. If Porsche didn't design one in there, you should be alright - espcially if you are fly-cutting the heads...

Too bad you're not doing this next year. I'm working on a book on engine rebuilding for the 911 right now that will have tips, tricks, and parts diagrams!

-Wayne

Wayne, thanks for the info. I will have a hard time finding a hill in south Louisiana..Road trip!!