Pontiac 455 fan clutch

[ladybird]

I have a 455 punched to 462 with a factory style fan clutch on it. I was think about putting a flex fan setup and was wondering if this would cause me to lose horsepower above 4300 RPM? That is the point at with the clutch now kick off. It is a 3 speed Turbo 400 in a 80 Trans Am. Any help is appreciated.

[Transamman25]

why not ditch the clutch and hide a small electrical unit in the shroud .. itll still look stock .. give ya quicker rev's and wont take so much hp from yer big block

[Chris 96 WS6]

Its going to take more than a "small" electric fan to cool a hoss 462. Probably would need a pusher and a puller. Still not a bad idea but will also require an alternator upgrade.

Most flex fans I've seen are designed to flatten out at high rpm so as to reduce parasitic loss.

[Transamman25]

BE COOL is making some super cfm fans that are relatively "small" that'll fit inside the shroud

[five7kid]

If you don't go electric, run the clutch. Flex fans don't do as well cooling the car at low speeds, and cause more HP loss than the clutch.

[rat454]

Functions as designed. At 4300 rpm’s the car should be moving fast enough to cool the radiator by the ram air effect of the motion. The clutch fan disengages and allows the fan to free wheel and spin as the air comes through the radiator. There is a certain amount of mass moving as the fan turns but with a big inch Pontiac horsepower loss to a spinning fan shouldn’t amount to much. If all you’re doing is racing it straight line with no street driving, then go to an electric motor drive water pump and an electric fan setup. If you drive it on the street, then get a heavy duty clutch type fan, use a good radiator shroud. It is surprising what a shroud will do to engine temp. Make sure the radiator is good and flows like it should. If it hasn’t been to the radiator shop in 3 years, then pull it and at least get it checked. Crap builds up in them and can quickly clog the fins. Use water (de-mineralized if you can get it) and antifreeze (or the pre mixed stuff) (antifreeze has a lubricant in it to lubricate the water pump bearings). Make sure there is plenty of air flow coming into the radiator. Look closely at any ac coils in front of the radiator keep them combed and clean…You might also think about finding a high flow water pump for it as well.

Does a clutch fan eat horsepower? Yes it does. Is that good or bad? It depends on what you use it for. It's bad if all you want is max horsepower for a short time and are not worried about driving in stop and go traffic. A flex fan can actually block the air flow at moderate vehicle speeds as it just sits there and spins laying flat like a plate…I’ve found in most cases that a properly set up clutch fan, with shroud will keep things cool.

I run a Victor water pump, a 4 core radiator and a heavy duty clutch fan on my 454 Camaro out here in the desert. It does fine and I lug it around town at 1600rpms...

Greg