Clewett Serpentine Fan Belt
 

Anyone have the Clewett serpentine fan belt set-up installed on their 964?

Every year I get close to ordering this setup, and every year I waffle. I think it may happen this winter.

Very similar to the 993 RSR setup and should do away with any shredded v-belt worries for years.


Andreas

Yes, had it in now for about two and a half years without any problems. Put it in right after a bearing failure was causing the fan to rub the housing. Simplifies everything and looks much better too.

I thought about it too. However I was wondering if there are any issues losing the harmonic balancer pulley.

Anyone have any issues with this setup because of the elimination of the harmonic balancer?

I may be wrong, but I believe the 964 used a harmonic balancer crank pulley, while the 993 is an all-steel design.

I think this tidbit possibly came from one of my discussions with Richard Clewett.


Andreas

Andreas,

You are correct.

The Clewett set-up eliminates the harmonic balancer. That is why I posted my thread on the 964 section. I should have been more specific about my concerns with the elimiination of harmonic balancer.

You are good to go on your 993--no harmonic balancer:)

The 964 should have the the harmonic balancer in place. In the long run it's not a good idea to remove it. Even Porsche left in place on the cup-cars and just removed the extra generator belt. The 993 is another story.

Thomas

Ok question begs to be asked then. - since the 993 and 964 are basically the same engine with a few updated changes - WHY does the 964 need the harmonic balance pulley and the 993 doesn't. What is the reason.?.

Different crankshaft design. The webs for the 964 were too thin and therefore a crank damper was needed. For the 993 they beefed up the crankshaft and took weight out of other moving parts.

PM

I know this is an old thread but I wanted to see if anyone in the last 4 years using the Clewett serpentine on their 964 has had a problem. Unusual vibrations? Bearing failure? Idling issues? Broken crankshafts? I'm looking for real world experience. I'm well-aware of the harmonic balancer issues and the science behind it, but the argument still seems inconclusive from everything I have read. I haven't seen any negative posts on the Clewett system anywhere online.

I finally took the plunge and installed the serpentine belt setup last year. Zero regrets. Works perfect, gives sufficient charge at idle, and takes away the possibility of v-belt failure.

I know it's a 993, but see page 2 of this thread for my install:

https://rennlist.com/forums/993-foru...stalled-2.html



Andreas

Bumping this thread four years later. Interested to know who is running with the Clewett serpentine belt, whether you have a LWFW, and if you’ve encountered any issues.

I’m aware of the Ongoing debate and concerns over eliminating the harmonic dampener and possible damage to the crankshaft. Wondering after 10 years if anyone has had any real world issues using Clewett and eliminating the harmonic damper, particularly in conjunction with a LWFW.

Thanks in advance,

Harmonic Balance Removed
 

I don’t have the Clewett Belt but removed my large harmonic balance pulley 4 years ago and replaced with a smaller crank single belt pulley system. I have had no issues with engine at all. DE and AX car, engine idles smooth and rev’s very fast ( I think due to the LWFW and the light weight smaller pulley.)