Hi guys, I was toying with the idea of getting a better radiator and appropriate thermo fan in preparation for the dreaded months of Jan and Feb, when I dangerously decided to think.. From what I understand, the clutch fan operates differently at different temperatures. With a cold start, I've noticed that I can hold the fan still and prevent it from spinning - I can't do so when the engine temp increases. I've seen a few unlabeled drawings of the fan assembly, and it looks like the rotating cylinder will spin at the same speed regardless of engine temp, but that as the engine temp increases, the blade assembly will exert more force on the cylinder, allowing the blades to rotate unhindered. What if there was a clutch fan available that essentially had the same dimensions (allowing drop-in replacement,) but with the aforementioned clamping force magnified? Will there be any sacrifices in terms of rotational speed of the cylinder - what with the increased mass of the clamping object? I can't see that there will be any other disadvantages to running the replacement clutch fan. If this product already exists - suggesting that my search skills leave much to be desired - where can I read more about it? Regards, Joe
I wouldnt bother changing the viscous clutch assembly to anything other than factory. the factory fan flows a maximum of 5000cfm or something crazy like that. If your viscous clutch is a bit weak then it could have leaked out some of the viscous fluid. If you increase the output of the fan it will put more stress on the blade and make alot more noise.
Agree with rollin_on_18_strong, I also wouldn't bother changing the viscous clutch assembly to anything other than factory. As I understand it (not sure how it does this and happy for anyone to correct me), initially when you start the car from cold (1st start) the fan should be locked for a couple of seconds until air flows past the sensor in the clutch. It will register the air temp as cold and release its lock and the fan should spin freely. As the air temp increases, the clutch progressively grabs until it locks fully. Therefore, when you start the car from cold you should be able to initially hear the fan moving air then quieten down as the clutch lock-up is released. Cheers, Peter