The Stovebolt Site Forums The Shop Area Engine Shop Fan clearance

I put the inner fenders on my 1950 GMC 2 ton with a 270 today and noticed with everything bolted up in the front that there is only about 1/2 inch of clearance between the leading edge of the fan and the radiator. When I replaced the water pump, I matched what was on it but that fan sure seems close. Is that normal?

My 48 Chevy pickup has about the same clearance as your truck. Mine was changed from a 216 to a 235, but I think that the 216's were the same.
Ralph

Thanks Oldtmy48. I wanted to be sure before I shorted my hoses.

Ever since I put a 261 in my 37 Chev pickup, I have noticed that the fan clearence has been very close. On mine it was about 1/2".

Recently I installed a new water pump and went to a double pulley set up for air conditioning. That caused me to go to a flex fan and even with the flex fan, clearence is still about 1/2".

I've had people make comments about it to me about it. One person said it seemed close, but he guessed the closer the better when it comes to cooling. The other comment I got was also about the clearence and then he added the comment, "I guess if the fan goes, it will tear up the radiator and everything else, but I suppose it would do the same thing if it was 1" from the radiator."

That made sense to me and ever since I haven't given much thought to it.

I think you're OK at 1/2". Short of some major work, that's probably where it will have to stay.
You could go to a flex fan with a small spacer and move further away from the radiator. In fact a flex fan in itself, without a spacer, would move the fan 1" to 1 1/2" away from the radiator.

The fan in my wife's 64 Comet is at the 3/8 to 1/2" space too.....been there for 100,000 mi. No trouble.

If the fan goes it will most likely sling outward. I had one go through the inner fender slicing the head light wires as it went. A guy on another forum recently had one go through his hood.

This would be a good time for the warning about staying clear of a fan's path of destruction when you're bent over a fender revving an engine.

Good safety tip. I had forgotten that my Dad had told me that he once send a fan through the hood and the radiator on a nearly new 1951 GMC trying to get out of some mud.

In my 49 with a 235 the clearance between my fan and rad is very close. Too tight to even get the fan belt off without removing the fan blade. I was looking at flex fans recently and the shallowest is still about an inch and a bit. Unless I actually try it I could not say if it would work. Incidentally this set up has been in place for about 15 years without injury to either component. however that does not mean it is right.

If your fan clears at idle it only get further away from the rad at rpm. If it clears by 1/2" don't worry about it because it can't get any closer.

Wrong! The fan wants to pull itself through the air. That's why a flex fan worries me.

As Tom says, the fan is propelling air back towards the cab. The equal and opposite reaction for the fan is for the blades to bend towards the front.

Sorry about the wrong info on the fan. I had it backwards. Thats what you guys are out there for.