Eng. Rebuild-10.3 to 1 comp ratio OK?

[Randy Webb]

Twin-plugging greatly increases engine "feel" according a BA column some time ago. Don't expect much hp from it. Increases in the displ. will give increases in hp in direct proportion. e.g. going from 3.2L to 3.4L give little increase but costs a lot.

Don't forget to incl. the cost of an engine R/R and whatever the downtime is "worth" to you while the machinist plays with your heads. I've had one in the shop in Portland for over a year.

[Bill Verburg]

The euro 3.2 used the 95mm 10.3:1 p/c. They run fine on 93/94 US pump gas (the hotter ambient T is the better gas is required), you would need an appropriate chip to use w/ this setup. As an alternative and since you are considering buying p/c anyway, why not use the 98mm Motronic p/c w/ 23mm wristpins and 9.8:1 c/r

From your apparent oil consumption, I would also suggest a good performance valve job w/ phosphor-bronze or manganese-bronze guides. If $ allows some hollow 964Club sport intake valves and 930 sodium filled exhaust valves or some spiffy undercut s/s valves motivated by a 964 or 993ss spec cam, don’t skimp on the valve springs and retainers.

Have a chip burned on a dyno to finish the package, twin plugging is not required w/ this package and the $ and hassle saved can be applied to the other areas.

If you are really ambitious a 76.4mm stroke crankshaft can be used to make a 3.6 on your block. But then you might as well do a t/p.

[Swiss911]

For what it's worth I had my '87 911 US spec converted to Euro pistons/compression about a year ago. Also had the cam changed to the 964 version and I'm very pleased with the result. I run the car in Switzerland and use 98 RON Octane gas. Installed cat bypass and had chip remapped to take advantage of the mods.

[ChrisBennet]

If you don't mind sticking with a factory chip you could run the Euro chip for the Euro pistons and if you weren't able to get good gas, just turn the fuel quality switch to position 4. The only difference between the Euro DME and the Euro "Low Fuel Quality" DME was the position of the switch. See this DME chart
Someone like Steve Wong ("SteveW") could easily make you a duplicate of the factory Euro chip for your car.
Personally, I think replacing perfectly good P&C (70K is nothing) for only 15 or so HP is a poor investment. I would spend the money on making the motor more bullet proof. Some competition valve springs (AASCO, Jerry Woods, EBS) and possibly some Ti retainers (w/new keepers) will close the valves faster so a missed shift won't be as likely to bend valve(s). A set of Raceware or ARP rod bolts will hold the bottom end together if you feel like winding the engine out past red line.
-Chris

[Bill Verburg]

A set of Raceware or ARP rod bolts will hold the bottom end together if you feel like winding the engine out past red line.

Good point Chris, When I took my own good advice the starting point was the crank and Raceware rod bolts. Everything else is predicated on that.

[toolman]

I hope that my P/C are not toast, all of this is about if they are toast. This would be my back-up plan. The engine might have more miles on it than the speedo reflects. You should have seen the rotors that came off a 75,000 car. You never know what happens to these cars in their past, I just want to be ready for the worst.