Ok I finally had a chance to get out and take some pictures. (Had to step away from this project for awhile due to life getting in the way sometimes) but thats another story!!

Anyway, can anyone tell if this is a proper clutch fan or anything that should be helping with either boilovers or overheating issues? As per some earlier posts in this thread?

Warmer weather is approaching here in the northeast and I'm looking forward to getting this issue resolved, so I can go for a few stress free rides.

 

check this , 5 responces down by Black Magic and down load the PDF
http://forums.corvetteforum.com/c1-a...ng-thread.html

 

Looks like a factory Schwitzer fan clutch. Do you have a shroud? Can't tell from the photo.

 

Did this car sit for a period of time with an empty radiator?

Things look pretty old and original. Could be scale plugging an old radiator.

May be time to call DeWitts?

 

Fan shroud appears in second photo. It would be a handful keeping the stock radiator located without one. 1964 shroud is sheet metal.

 

Make sure that the fan is 1/2 in and 1/2 out of the shroud on the fore-and-aft axis. There is much written about these clutches, but if you have a big block clutch installed with its shorter shaft, and/or the pulley hub is pressed too far onto the water pump shaft, then your fan location may be too far backed OUT of the shroud in the AFT direction. Look here for more info:

http://licorvette.com/Corvette%20Fan%20Clutch.htm

I see a large gap along the bottom of the radiator. If you buy some foam rubber window/door weatherstripping, you should be able to sandwich it all around the parting surface between the radiator and the shroud. This will prevent any leakage and will greatly enhance the cooling capacity of the system by preventing bypass air. There are seal kits sold for Corvettes with air conditioning, but the foam weatherstripping is a lot cheaper and just as effective.

Of course, you still have to check your timing against the spec sheet that I gave you. You should also check that your heat riser is wired/jammed wide open, which will prevent it from becoming stuck closed.

If you don't see or feel any oil around the hub of the fan clutch, and the bearing has no wobble in it, then the chances are excellent that it's functioning as it should. I can't say that I know of any reliable test for a bad fan clutch other than the checks I mentioned above. There are some people that like to count the number of revolutions that the thing makes after the engine is shut off. This is not a very scientific way to go about it, and I don't use it.

If all else fails, then buy yourself a replacement clutch. They're cheap enough at around 100 bucks.

If after all that, your problem still exists then I'd start to look for head gasket leaks, thin cylinder walls and other such esoteric causes.

 

this thread is about 90 days back, but never the less, the fan clutch is aftermarket centrifugal and not OE type thermostatic.....but it still should work!

 

I just went back and read post #16. Here is part of it, and the highlighted sentence reinforces what I said in my post #26, just above, about the daylight at the bottom of the radiator. I think that we have just isolated your problem:

"Yes I believe it is the original radiator, but I have only owned the car since Mar. 2011. It was originally a fuel injected car but the PO removed it, and a few other mods here and there. (I find them as I go)

The shroud appears to be in good shape, exept the flap is missing at the bottom.

65tripleback, thank you for the timing advice, I am going to try and work on that this weekend, (supposed to be near 60) so might be a good time to work on it.
It is a 300hp 327, so I will use your notes."

 

All the of the shroud rubber in the world isn't going to solve his issue. Yes the lower flap plays a part in overall cooling.

But his tank is barfing and his gauge is pegged. It's either a water pump,thermostat,radiator,air in the system etc...

My hunch is his coolant system is full of garbage and it's clogged the radiator.

All of the cures here are valid.

But other than a bad fan clutch. They only offer incremental improvements in cooling at idle.

Remember you aren't into the hot time of year.

 

I recently had the same issue after having my heads rebuilt. I wasn't very careful when I filled the radiator and must have had a big air bubble in the system. After I "burped" the system I have had no problem with it overheating. It's worth a try if you haven't done that yet.

 

Thanks for the reply's
I will try all of the above, especially a good system flush.....the fluid all looks good of course, but the car sat for 19 yrs before I got it, so it could very well be clogged up.

 

I appreciate your posts, and I will work on the gaps around the radiator, it certainly can't hurt, and with all the other great tips here I'm sure to get it resolved. Only problem is, as someone mentioned earlier, we aren't into the hot weather yet, so it will be a little while before I can give you guys a diffinitive answer.....stay tuned

 

Nope - that's a Schwitzer plate-type thermostatic - they were used interchangeably with the Eaton coil-type thermostatic. However, whether it still works remains to be seen. Most likely the car has other cooling-related issues, especially if the radiator is original and the car has been sitting for 19 years.

 

The 19 yrs sitting mostly explains your cooling issue.

Just a heads up. If your radiator is clogged? A flush wont help it. FYI a proper replacement runs about $800+. If you need a new radiator?

May I suggest DeWitts.

 

In his first post he states: "..........................after an hour of easy cruising around............................."
that the thing boiled over only after idling while stationary in a friend's driveway.

If the radiator was the issue here, and/or there was trash in the cooling system (which is highly unlikely), then the thing would have boiled over while he was underway, while cruising.

I stand by all my suggestions to him which include the timing, the fan's fore and aft location, the heat riser valve, and especially the gaps between the radiator and the shroud!

 

Ouch!! Not the answer I was looking for, unless of course that price includes you coming over to do the installation..Ha HA!!

Thanks for the heads up though, I'll check it out

 

Read this - it will help you understand how your Corvette cooling system works, how to diagnose it, and debunks a lot of "internet legends" on how to fix it.

http://www.lbfun.com/warehouse/tech_...em/cooling.pdf

 

It's identical to the original one on my 65.

Jim

 

John, Great article!! Good read and very informative

I'll definately archive that one.

Regards,
Mark

 

GOOD NEWS !!!

After all of the above fantastic information, and advice....all of which was tried and tested, (except for one thing, that was kind of mentioned, but never really talked about in detail).
I finally resolved the "Boilover" issue tonight.
You guys are all going to smack your collective selves in the forhead when I tell you that the culprit in this mess was non-other than the Radiator Cap itself!!

Can you believe it? It never dawned on me that the damn thing wasn't original, and non-the-less, defective.

Picked up a new one at NAPA today and "poof" no more boilover.

But heck after all the checking and replacing I should have a pretty decent cooling system now

Just wanted to report back, and Sincerely thank all that replied for thier help.

Now on to the next project ...........