The Stovebolt Site Forums The Shop Area Engine Shop Electric fan/ engine cooling

So, I just purchased this truck, and at some point someone popped a 350 in the engine bay. This is all well and good, but they put a engine mounted fan on it, and left a good 4-5 inches between it and the radiator and no shroud. Now, it's well into the 90's around here, and my poor old engine just couldn't take the high-rpms of higher speed travel without an overdrive in the tranny and tried to overheat. So, to kill two birds with one stone, I'm planning on moving to an electric fan. However, I need to know what sort of CFM I need to be looking at to keep this guy cool. Anyone have any knowledge on this?

Around 2100-2400 cfm. Don't mess with the small stuff. You'll be throwing your money away...so be preppared to pay a little more. I'd say around $175 bucks. Most local stores will be selling the 1800 cfm (or close to it) They can probably order you a bigger one or you can try some of the vendors or hot rod shops.
Locally, I saw a 2100 advertised for $150 so do your shopping before you lay down the green stuff.

Excellent. Thats exactly what I needed to know. Would you recommend a single or double setup?

I'd measure across my radiator. Just my guess would be a 16" wide fan and a single should do it as I imagine your engine is not sitting as low as some in our AD trucks. I'm sure others will voice their opinion and then you can sort all of it out.

I might add that I made my own brackets out of 3/4" wide 1/8" thick Aluminum. You can get a 3 ft stick at Lowes or Ace hardware ect. I don't like sticking those plastic "pins" tht comes with some fans through my high dollar radiator..... but the bigger fans usually come with a "slot" to use a small bolt to attach the bracket. Bend the aluminum to fit and then fasten on a bolt that is also holding the radiator on. To do this I cut me a piece of coat hanger and bent as a template and then cut the aluminum to the template, drilled the holes and it looks good.

I have also read that a puller fan is better than the pusher fan.

couldn't take the high-rpms of higher speed travel

If it overheats on the highway, it's not the fan, and an electric won't help.

I totally agree with Panic, its not the fan if its overheating at highway speeds. The airflow should be enough to cool it.

What radiator does it have?

Hows the air flow around the grill opening?

Is the radiator sealed around the core support ao all the air goes through the radiator?

Add a shroud and clutch fan, they will work better then any fan you could add.

Joe

Not sure on the radiator model. I can say that the tranny cooler is partially obscuring the radiator. I'll try to find a place to move it to.

Have you checked all the other reasons for overheating?
bad radiator cap
plugged radiator
bad thermostat
bad waterpump
and my personal favorite, head gaskets.

I checked the thermostat, and it seems to be opening ok. The cap I'm not sure on. The engine was in the 180 area when i loosened it to the pressure release notch, and it didnt seem to have pressure behind it. As for a plugged radiator, pump or gasket, I havent really gotten to that yet. The more i think about it, the placement of that tranny cooler is probably blocking a signifigant portion of airflow. Also, if you've seen my other thread you may know i have a possible retarded timing issue, which may be causing some of this.

Yes, timing can have affect on temperature. Get your tune-up all set before throwing money at cooling, but a radiator cap is a cheap investment in peace of mind.

Thanks everyone for helping the newbie. I'll give this a try tonight and see what I get. Will report back once its finished

Adjusted timing, made sure carb was tuned right, added an electric fan and thermostat, and relocated the tranny cooler. All seems to be better now. thanks for the help!