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Author Topic:   Shroud
posted September 13, 2003 01:38 AM
Ok I dont think I have any heating problems right now(new car so cant say for sure untill it hits the track)but it has no shroud at all, just six blade steel 17 inch fan and brand new radiator. I have a shroud but the fan will go in the shroud a good ways and the shroud will come back close to the motor. The problem I see is being hard to chage belts etc, but will it cause heating problems with the fan and front of motor closed in with shroud

rico 08
posted September 13, 2003 08:40 AM
I never had any luck running without a shroud,the fan is just lazy and won't pull the air thru the rad,i like a four blade fan better,if the air can't flow out of the shroud you will have problems,look for some of the ford style fan shrouds they are real short.

posted September 13, 2003 10:23 AM
one way to tell if your moving air is take a shop rag and put it on the front of the radiator while the car is ideling it should stick but i'm gonna agree with rico get a smaller fan and a good shroud do you have a spacer on the fan now might want to take it out and put in a smaller one if so

posted September 14, 2003 01:55 PM
You need a shroud on a gas motor, period. Alcohol motors are different. The shroud should fit the fan with about 1/2" clearance all around. Maybe a bit more on the right since the engine can torque that direction if you have stock type rubber mounts. The fan should be half to three quarters into the shroud. If your shroud is too long, cut it off or make another. I like to keep a minimum of 4 inches between the fan and the radiator. This allows the fan to pull air from the corners of the radiator.
A fan will try to pull most of its air from its outer diameter perpendicular to the fan shaft. A shrouds prevents this and makes it pull from the front. The four blade fans pull about the same amount of air as the 6 blade race fans but the 6 blades actually use slightly less horsepower. Do not use a metal flex fan.

I would stay with the 17" fan size you have. A smaller, 15", might work but there is a marginal difference in power required and the 17" is good insurance against heating problems.

posted September 15, 2003 01:06 AM
thanks I have had good luck with the six blade race fans, my last car had 18 inch but I went with 17 this time. I made a shroud today and put on it boy does it move some air now wow, thanks guys

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