SoloRacer

I have a 914 that I am turning into a track car. The car is currently set up for a Porsche 6 cylinder. I would like to run the car in GT2 but if I read the regulations correctly the largest displacement engine I can put in the car is a 3 liters. I'm told the 3.2 is a better engine than the older 3.0 and was wondering if anyone has considered destroking a 3.2 to get 3.0 liters. What are the reasonable power limits of such an engine? To be competitive I figure I need around 300 hp to stay with cars on the two straights at our local track.

Trak Ratt

The Carrera 3.2 (84-89) has a longer stroke than the 3.0 engines. Though I have certainly heard that the stock 3.2 is more desirable than the 3.0, it is usually because of the more advanced electronic fuel injection & some other upgrades. We have both & though I would like my wife’s 3.2 in the SC it’s only because of the added size & fuel injection. Since you can use very little of a stock 3.2 engine beyond the cases & heads why not sell the “better engine”, find yourself a good 3.0 core & start from there?

Tom Tweed

If you need 300 HP out of 3 liters, be prepared to open your wallet very wide. Only the RSR slide valve motors made that much power in the factory lineup, and they are mega-rare nowadays.

You could get a good 3.0 core motor and add some very high compression pistons with some good head porting and flow work and racing valve springs, some stout aftermarket rods (Carillo or Pauter), Raceware hardware, a big cam, some Weber or PMO 46s and headers and you might get close for $12K+, and still have to run $5/gal. race gas and freshen it up every 40 hours. That's racing...

Martin S.

Tom Tweed is right on the money...300 HP out of a 3.0 or 3.2 motor is going to cost some major bucks.

To get 282 HP, out of a 3.2 motor, in 1989, Porsche needed a Turbo charger and an intercooler.

Look what Porsche has had to do to get 320 HP out of the 996 car, Vario-cam, vario-ram, 4 valves per cylinder, very sophisticated electronics, 2 plugs per cylinder, water cooling, my heavens, this is staring to sound like a Japanese motor.

Read Bruce Andwerson's Book, The 911 Performance Handbook. He'll give you a reality check on what it takes to get 300 HP out of a boxer motor. <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />

Tom Tweed

As a data point, here is a link to the dyno sheet for the 3.4 liter engine I am putting in my '73E track car now:

This is on a chassis dyno, so 280HP equates to something like 310 at the flywheel, probably, with drivetrain losses. It is a simple "old-tech" engine, built on a 3.2 base motor with 98mm Mahle sport pistons and cylinders (10.5/1), Carrillo rods, PMO 50 carbs, a special Webcam grind, Aasco valve springs and single plug stock 3.2 heads, machined to mate with the 3.4 cylinders. I'm sure with some headwork, more is possible with this motor.