i have an 83 Bird LG4 with the 5 blade thermal clutch fan. i have an intact air and and fan shroud. i was wondering if wiring in a pusher fan to the other side of the radiator is a good idea or not? i was thinking it would help a lot while sitting in traffic in the middle of summer.

if i was going to get a pusher fan, how much cfm would it have to be to keep up with the stock clutch fan? how much cfm does the stock clutch fan move? either way i'm keeping the clutch fan. i know jeeps have both a clutch and electric fan and was wondering if this could help on thirdgens.

suggestions?

 

I'm going to do that when I get my A/C operational, wiring it in to run with the A/C on (or with a couple of thermo switches), instead of getting a heavy duty clutch. Belt driven fans moves air according to rpm's so it's hard to compare them and I don't think it's critical that it "keeps up" with the stock fan. I think they'll complement each other and you'll get the best of both worlds.

 

for sure keep the clutch fan. I have an 88 and it kept over heating with just one electric fan. As soon as i put the clutch fan on i never ever have over heating probs. but i think the electric fan in front will work.

 

You could try mounting a puller electric fan inside your shroud. My 82 corvette is like this from the factory. But your biggest gains would be to seal the fan shroud to the radiator and seal the a/c condensor to the radiator. That way as much possible air is pulled through the a/c condersor and radiator core as possible.

This is how my corvette is, they just used dense sponge type foam to seal everything and I've never had a problem with that car getting hot. I'de try that, if it worked on a vette it will make yours better too.

 

do you think putting an electric fan on the other side of the radiator as a pusher will be restrictive? wouldn't the cfm of the electric have to be at least the cfm of the clutch fan if not more?

anyone know how much max cfm the stock thermal clutch fan pulls? what size and cfm electric should i get? what have you guys used? recommendations?

 

Don't understand why you even need one. I can drive my 82 which has a electric 1990 fan on it and it never gets hot at all. that mechanical fan should draw more then adequate air under any conditions.

 

just thought it might be a good idea. there's a lot of traffic where i live- especially in the summer. so that means a lot of sitting at idle in 95*-100* weather in the summer. my car runs very hot in those conditions even with a good fan clutch, air dam, and fan shroud. thought a helper fan sounded like a good idea.

anyone at all know how much cfm the stock clutch fan fulls at max?

 

hmmm .... I run in gridlock conditions in the california heat with a/c on blizzard and it doesnt run hot ..... Try a 3 row brass replacement radiator

 

Look at Fast355's comment in a nearby thread. I think he's right in that a mech fan outcools an electric fan above 1000-1500 rpm. Consider that a 16 Amp fan equals 0.3hp, and a mech fan is reputed to draw 10-15hp.. The sheer noise from a locked-up mech fan at 2000 rpm tells me that it could indeed lift a small airplane.. At idle an engaged mech fan also makes noise, but not quite as much as an electric does.
I've had a clutch fan fail on me, in two ways, and an electric fan can also fail. Having both would be good insurance against overheating under any circumstances. The shrouding effect would be non-important.

 

punkdude, I was on Mr. Gasket web site last night and they sell 5 different fans 9" to 16" & list CFM. other sites also list CFM for fans they sell. For traffic sitting & overheating proofing I agree w/ Fullsizewagon that you'd have a great set up (single 16" elec fan on my car sometimes lets me dwn).

 

You wanted a cfm number, so I took some measurements on my old clutch fan. It's 19" in dia., subtract 8" for the hub area, giving a 1.61sqft effective area. It has a blade angle of approx 45 degrees, and a mean diameter of 13.5", giving a mean pitch of 3.5ft/rev. This calculates to a flow of 5.635cuft/rev., or 2820cfm @ 500rpm, or 11270cfm @ 2000rpm (when fully engaged).
Note that these are only approximate, simplified, and theoretical figures, and that the rpm's indicated are at the fan itself (water pump pulley).
A Standard Trimline #116 electric fan has 16" dia, 11 degrees blade angle, 1860rpm, 1450cfm, and a 10A current draw. The S-Blade version, #396, has 1840rpm, 1700cfm, and a 13.4A current draw.