Eb back to the drags

[AUTickford]

After i got the eb fitted with thermos i took it to the drags and improved on my 15.77 to a 15.42 so the fans made a worthwhile improvement over the propellor and i dont have to listen to the poxy racket made by the old fan. :

[needaXYGT]

sounds good. but can someone tell me what the purpose of the clutch fan is, cause iv never realy known, and also how do the thermos improve over the clutch fan.
my guess is that the engine has to turn the big fan, where as the the thermos run them selves, correct?

[mcflux]

Clutch fan - fan with a viscous clutch hub which attaches to one of the engine pulleys. When the engine bay heats up, the viscous clutch hub engages so the fan isn't freewheeling. The fan draws extra air through the radiator, cooling the coolant. The clutchfan saps power from the engine by acting as a drag on the pulley system.

Thermofans - they're electric and aren't attached in any way to the pulley system. They're activated by a temp sensor tapped into the coolant, and although they don't sap power from the pulley system, they can draw power from the battery/alternator thus producing a different type of load on the whole system. But they're generally considered better than clutchfans.

[needaXYGT]

ah ok. so wouldnt the clutch fan operate when things are hot? i only ever hear mine when things are cold?

[Nashy86]

Originally Posted by needaXYGT

ah ok. so wouldnt the clutch fan operate when things are hot? i only ever hear mine when things are cold?

it should work when things are hot
mine works when first started on a cold morning, its to do with the viscous clutch, probably because of the very low temp, or having been sitting still and not spinning for a while (eg starting on cold mornings after sitting still all night) mine stops after driving a block or so...