Doing another 3.6 conversion

[scca_ita]

But his time I want to take off the big three wheel vibration damper and go to a single pulley on the crank. This way I can use the stock 3.0 - 3.2 sheet metal and cross member (mount). I was down in Phoenix and went by Patrick Motorsports and there was a 3.6 (964) conversion car with this setup which was a nice clean fit. I hate it when I look into my engine compartment and can see two inch gaps between the sheet metal and side frame rails.

QUESTION: Which motor is better suited for removing the big pulley. A 964 or a 993 given the differences in the way the crank is balanced?

[Bill Verburg]

The 993 is internally balanced the 964 uses an external damper. People remove the external 964 damper all the time w/o suffering any dire consequences but I wouldn't. The 964 crank is a very stout piece of work.

The reason not to remove the external damper is that it's way too easy to go from this



to this



The 964 is the only externaly damped 911 motor since some T models way back when, yet it is often the prefered crank for race motor buildups

[Mifintifin]

I agree with Bill. IMHO you should avoid reengineering. If the vibration dampener wasn't needed, you can believe Porsche wouldn't have it there! I have also heard of the overheating problems caused by certain single pulleys available.

Besides, the two inch gap is a result of the sloppy way the conversion was done. Done right, the 3.6 sheet metal seals perfectly with the early engine bay seal, just like the original 3.0L sheet metal. Here are a couple of pictures of a 964 engine with the sheet metal done correctly (the rough finish is mastic). I also have 993 pictures, email me and I'll send them.


This technique of modifying the rear pan allows the pan to seal perfectly with the 3.0 engine bay seal. Why don't you just get a used 964 pan and redo it?

Mifintifin

82 SC Coupe (993 engine)
83 SC Cab

[widebody911]

I had the PM pulley, and the car ran warmer with it. I went back to the stock pulley, but removed the dampner, so it's kind of a compromise between the two setups.

[john_colasante]

964 Cup cars used a single crank pully so you can get one of those. That's a real race car after all.

[Bill Verburg]

Here's a pic of the Cup car single pulley arrangement John mentioned;