964 Camshaft vs 3.2 Camshaft

zorin · 10-17-2009, 06:59 PM

I am running a stock 3.2 L '87 Carrera engine with Zenith Carbs (36mm vents, 1.60mm main jets) and no DME. I also have a set of 911SC 3.0L camshafts that were machined to have 964 profile. My question is that will I be gaining much by replacing camshafts of 3.2L engine with 964 camshafts?

The disributor advance timimg is set at 30 deg BTDC starting at about 4000 rpm. (91 octane fuel) . I will be sending it for recurving soon but it seems that I do not get much torque out of the engine until I pass 5000 rpm. Can this be fixed by recurving the distributor or replacing 3.2 L camshafts with that of 964?

Thanks.

jkarolyi · 10-22-2009, 12:15 AM

Not sure about the answer to your question about the cams, but the distributor needs to be recurved when you convert a 3.2 to carbs. Get that done before messing with anything major like camshafts.

kiato4 · 10-22-2009, 06:36 AM

What type of distributor and ignition system are you using?

jkarolyi · 10-22-2009, 01:04 PM

I just remembered that the 3.0 engine you had came from MotorMeister...in which case those "964 cams" were probably reground with a belt sander.

Either that or they didn't bother whipping out the belt sander and just reinstalled the stock cams telling you they were 964.

Glad to see your car is running again. Once you get these bugs worked out you're going to have a fun ride.

zorin · 10-23-2009, 05:22 PM

Thanks Guys,

- Any idea what the timing advance curve should look like?

- I am using Bosch stock ignition and using the weights and springs from 3.2's dummy disributor. I get about 6 deg at 1000 rpm and 33 at 6000 rpm.

- I have the camshafts form Motormeister taken out from 3.0 L engine. It looks like they were grinded in the buttom of the knobs and they have marked "964" on it. Also, the pistons that I took out look like 3.2 pistons. They must have fitted them in 3.0L engine.

- They way I see it now, I had more torque and power with MM engine through a wide range of RPM's. Too bad it did not last long. Can storing the car for the winter do this to an engine? i.e. stuck oil ring and piston seize?

Thanks again.