The Stovebolt Site Forums The Shop Area Engine Shop Fan Grazing Radiator.... Problem?

Hi,

A while back a mechanic installed a new fan with a spacers to bring it closer to the radiator (over-heating problem). A year's worth of driving and a few bumps later, my radiator is showing signs of contact. This is not great but, as far as I can see there's no fluid leaking out. Assuming that this does not get worse (all the contact that is going to happen did happen) anyone see any problems with this as far as long term issues that may be caused?

the picture is here: https:
(//plus.google.com/photos/113956755236860259179/albums/5387409742978612849/5911262204449407650?banner=pwa&pid=5911262204449407650&oid=113956755236860259179)

thanks!

YES, problem! Fan shouldn't hit radiator, no matter what. If it does it's
just simply to close. Even if it's not getting into the cooling
tubes, bending the fins over reduces the airflow over the tubes
and will drastically add to your over heating problem.

Denny G

Check motor mounts or any possibility the engine is getting in to the radiator. Unlikely, just covering all bases. I would estimate the proper distance between the radiator and the fan to be about 3/8" to 1/2". This ensures the natural flex of the fan when stomping on it wont hit the radiator.

Cant get your link to work, so is it a new style 235, original 216, what?

If it has been hitting throughout the course of a year, it could keep getting worse. You might want to try putting Dykem (or radiator safe equivalent) on the radiator, if it is gone after driving around, you still have contact.

Might want to talk to your mechanic about removing the spacers and adding a cowl. It will give you better air flow over through the entire radiator, and give you more clearance.

No clue if the radiator is still good. Someone with more knowledge than I will answer.

I see by the description on the photo that it is a non standard fan. I think you have a bad modification and you need to take it back to original and solve the real problem. On my 51 216, the fan is about 3/8" from the rad. On my 38 Master, the fan is a lot further back from the rad and the fan does not have near the same area. I don't know why it works but each design was well tested.

Well my .02 i think i would not try to do a temp fix. I would find out the real problem and correct that. I just spent a lot of money rebuiling mine and i know parts are not cheap not like the sbc.

Well i could not get your link to work but one thing i would be affraid of is weaking the rivots on the fan or causing a stress crack on a fan that has been hitting the radiator and i am sure it did not do the water pump any good either. I hope you did not throw your fan out of balance and causing your pump to shorten bearing life or weaken the fan blade and it ends up with a piece of metal in your radiator. I just hate to be left stranded. Good luck and keep us posted.

Here is the link

Looks like another candidate for my water pump relocation adapter plate.

Believe it or not I already put that adapter plate on (and A short shaft water pump). It was easier to install than I thought (having never drilled and tapped a block before. Thanks

The fan blades actually move forward a bit while under load (high RPMs). Mix in a bump at the right time and you can at the least damage a fin, at worst rupture a cooling tube.

In my 43 Chevy the fan is at least 1-2 inches away (at least) from the radiator... but still inside the shroud.

Are you sure the fan is not in backwards so that it is trying to push air forward?

Dennis

So I am unfamiliar with a short shaft waterpump fo a 216. How does that work? I didn't think the shaft could get any shorter on a 216 pump.

There is no "short shaft" water pump for a 216. There is a short shaft water pump that some people use on later 235s or 261s in earlier (pre-55 first series) trucks. I think that truckernix knows this - he is referring to the statement by Truckn39, "I already put that adapter plate on (and A short shaft water pump)". Truckn39 just stated it a little incorrectly?

The relocation plate allows the earlier water pumps to be used on the later block - these have "natural" shorter shafts in comparison to the longer shaft on the water pumps used on later 235s and 261.

Tim,
that is correct but as you mentioned, something doesn't add up with the previous statements.

On my 235" 49 half ton I have less than 1/4" between the fan and the rad. If a fan belt breaks I'd have to remove the radiator to replace the belt. Been that way for 15+ years although I cannot say I am happy about it.

I checked my 38 Master and the space between the fan and the rad is a good inch. As I said on my 51 it is about 3/8 " .

Thanks gents. I am going to move my fan back a bit and try to eliminate any possibility of contact with the radiator. I'll straighten out any mini-fins of the radiator that got pushed over to maximize airflow.

I'll let you know how it goes. Cheers,

Doug

Dennis, you would have to reverse the pitch or the direction of
rotation for it to blow forward.

1/4-3/8 clearance sounds about standard for a stock AD, mine
runs about that and same thing as Bill, I'd have to remove the
radiator to change the belt. So.....next time you have your
radiator out gents, take advantage of it and put a new belt on.

Denny Graham
Sandwich, IL

TF trucks I've had with clearance so tight the belt wouldn't come off I just took off the fan, bit of a pain but easier than removing the rad

Bill