How much CFM do i need through my radiator

[64coupe]

I just got done my blow through setup on my 65. its a 302 iron heads, alum intake, paxton sn92. 3 core radiator, stock style water pump, 160 degree stat. how much cfm should i need. will my stock fan with a shroud still control the heat? I have had two different elec fans and both didn't push enough air. one was 1600 cfm which i thought wouldn't be enough and i was right. Is a stock fan with a shroud 3000 cfm? i think i read that somewhere. Currently it will run with the 1600 cfm elec fan at 210 degrees with the heat on high!!! Any help would be appreciated or someone that know someone with a similar setup? Thanks

http://videos.streetfire.net/video/6...hru_166117.htm

[68 Coop]

I have basically the same set-up, and my fan PULLS enough to keep my engine cool, even in Hell. Didn't see the paxton, but I think fans do better pulling the air than pushing it. JMHO

[66 Restomod]

We have a 3 row radiator and an electric fan that pulls 2300 cfm. The temp will creep up to about 3/4 of the safe zone on the 66 gauge when idling in 90 degree temps. Sorry, dont have a true temp indication to post. I read that you want to run 2300 cfm on a 3 row radiator to keep it cool.
I went with the curved blade model to reduce noise. When it kicks on it is a wind tunnel in the engine bay!
Here is the chrome one from Speedway we got for $99.
http://www.speedwaymotors.com/p/4374...ectic %20Fans

[64coupe]

i have a 65 the radiator is a lot smaller. also my fans did pull sorry i didn't put PULL, i did put push tho my mistake. how did you not see the paxton its the large polished object on the passenger side lol. I'm honestly looking for someone that has a 65/66 with a supercharged 289 or 302 to see what their cooling system consists of. Thanks tho, i do agree that i think fans pull better than push.

[68 Coop]

Originally Posted by 64coupe

i have a 65 the radiator is a lot smaller. also my fans did pull sorry i didn't put PULL, i did put push tho my mistake. how did you not see the paxton its the large polished object on the passenger side lol. I'm honestly looking for someone that has a 65/66 with a supercharged 289 or 302 to see what their cooling system consists of. Thanks tho, i do agree that i think fans pull better than push.

uh... I didn't watch the vid, I only read the post. My bad.

[68 Coop]

Yep, you can't miss it, that's for sure. Nice!!!

[66 Restomod]

With an electric fan you will be using the battery to run it and your alternator should be rated for 100 amps to keep up with the load.
Our 2300cfm fan draws 16 amps...
Info in case someone is thinking about installing one.

[indyphil]

Thats good info.

Heat rejection is a complex issue, timing is important, fuel mixture etc... Total hp levels and blowers dont add as much to the heat rejection as you would think, displacement is the killer. An overbored big block making 500hp will need more cooling system than a blown 302 making 500hp.

The concept you need to know here is that manufacturers CFM ratings are basically worthless. Look for a fan that pulls 13-15amps or more. Anything less wont be capable.

You also ought to consider a larger aluminum raidiator with twin electric fans.
Its simple to do. The late 60s broncos had an upper raidator inlet on the passenger side. Use the broncos hoses and a universal alum radiator (found listed for chevys with pass inlet and driverside outlet) - go thick and wide - like 24 inches wide. You might need to relocate the battery. Or you could buy an expensive custom made to fit radiator.

The bonus with twin fans is you dont need to worry about the water pump pulley snout or fan thickness.

If you really want to stay with the 65-66 radiator youll need to get a meaty fan and a high flow water pump.

So theres 3 essential elements to the cooling system
Radiator
Pump
Fan

Youll need to upgrade at least 2 of those items to stay cool. a 3 row radiator isnt considered a real upgrade. A 24 inch wide aluminum would be.