RobsCountach

I know there's a clutch fan for engine cooling; However, why are there 2 electric fans ? I could guess that one turns on for the A/C and the other is a helper for the clutch fan if it can't keep up with the temp ?

Anybody replaced that clutch fan ? I don't like there general design, but the bolt pattern doesn't fit any flex-fan out there...

Thanks,
Robert
98 SL600

RobsCountach

Mmm, surprised this is such a mystery or are there just not that many SL folks here ?

MB AMG

Good question. It's the same in the W210 E class until in 1999 or so when they replaced everything with 1 electrical fan.

SUNILP

it's also the same in many other models. My w124 made in 92 has the same design. There are a few people that have replaced the main clutch fan with an electric fan.

SL600 V12

Whoa whoa whoa whoa. Hold the hell on now here.

I have a lot of experience with exactly this subject, so let me give you a few pointers:

1. Flex fans suck Or rather they don't suck. Or they suck, because they don't suck enough. Any clutch fan in the world will crap all over a flex fan. They're useless.

2. The point of the "clutch" in the clutch fan is to prevent horsepower loss. When you rev your engine, the fan pretty much freewheels at its current rpm and catches up with the engine. This causes a 1-2 horsepower draw at best. This has been tested again and again to death. Converting a working clutch fan to an electric will get you almost no horsepower at all. Any horsepower you get you will not be able to feel, and you will not notice any statistical gain in acceleration either.

3. A clutch fan sucks more air than anything electric, this side of twin Continental fans or something.

Trust me, because I have screwed around with cooling systems more than most people have their girlfriends. You will make no improvement upon a clutch fan/electric assisted cooling system. Never. Ever. Not unless you happen to know how to fab in a nice hydraulic cooling fan, but I doubt it.