Ty18769

Hey guys,

I'm a new C3 owner and one of my first orders of business is to get the cooling system functional on my '72. Bubba has visited, and it ain't pretty. I've read many threads on the cooling loop before posting but wanted to run the situation by you all to get the facts. Initial indication is that it was running hot (225) putting around the country for a half hour. I took it home because of excess temps. Subsequently, I attempted to get it up to speed to see if highway speeds would cool it down. No dice. Hovered between 225 and pegging the temp guage. Stopped immediately and hauled it home. After inspection, no wonder. I'd be surprised if ANY air is moving THROUGH the radiator.

What I see:

I noticed a little play in the water pump bearing so I plan to change it out. I don't believe this is any cause, but I will feel better changing it out.

I have a 1972 K base engine with a 26" copper radiator and no overflow tank. It looks to me like there are zero seals on the core support, and zero seals between the rad and the shroud. There is a large 2.5" gap between the bottom of the rad and the bottom of the shroud. further inspection.

I see an incorrect shroud installed (numbers stamped in the plastic: 3956119) which would be for a big block and would have an extension with it. further inspection

I see no upper radiator supports, so the rad is sitting at more of an angle toward the fan than it should. This is causing a large gap up top to go along with the missing seals as well. further inspection.

Bottom radiator hose is squishy, like it was replaced at some point, but not with the stainless coil inside. That or the stainless coil disintegrated.
further inspection.

So here is my parts list so far. Since I'm going to change the pump out, I'm hoping to tackle the rad situation at the same time. I'd like some advice on what seal kit to get.

already bought:
1.) Water pump and good gaskets & sealant
2.) Thermostat and a good gasket & sealant
3.) Plastic Shroud # 3956109 I believe this is correct for a '72 base 350 with an automatic, without AC and a 26" measured radiator. If anyone can confirm this, I'd feel better.
4.) Lower Radiator Hose with Stainless Coil
need to buy:
1.) Need help choosing a seal kit for the radiator. Suggestions? http://shop.docrebuild.com/1972Corve...FanShroud.aspx suggested
2.) Need help finding the upper radiator supports (RH and LH) that will bolt up to the top of the core support and align the top of the rad. Suggestions? purchased from site member, with cushions.
3.) Am I missing anything? Any bumpers, or cushions that would be nice to have? Pushpins? Any thoughts on cleaning up the rad core support? I thought it looked decent considering all the missing stuff: pointed out that I needed the front air dam spoiler: http://www.ebay.com/itm/Corvette-Fro...38.m2548.l4275


I would appreciate any help. Thanks in advance!!! And yeah, I'll get her cleaned up....as soon as I get her cooled down!!!




pictures enclosed:

EarlyC34me

I had the same issue. I had mine recored. Problem solved. It was not cheap though.

EarlyC34me

Also do you have the bottom black air deflector. This is a big issue if missing. It is th bottom trim piece you can see it in this photo running under the front plate

EarlyC34me

There is a seller on ebay right now selling the upper supports i think his ebay id is glenn454

Ty18769

Looks like I am missing the air dam as well. Thanks!

Wee

Glenn454 is a good seller.....I have bought many parts from him.

Brian

sunflower 1972

Missing that piece is a biggie. I'd install one and take it for a drive. I'll venture to say the engine temp drops 15 to 20*.

Alan 71

Hi Ty,
WELCOME!
A source for the foam radiator and shroud seals you might want to consider is Dr. Rebuild. They have a site you can peruse and order from.
Be sure to order the kit specifically for your car, 72, sb, auto or a/c. Also order the foam rubber seal that is glued to the top surface of the core support and forms a seal between it and the bottom of the hood.

The seals ensure the air moves through the radiator core not around it.
The radiator really 'breathes' through the 2 openings in the lower valance.
So it's vital that the fiberglass air dam have the black plastic 'extension' on it.

In addition there should be a black rubber flap stapled to the inside of the fiberglass valance which insure the air flows through the radiator and not below it. Check to see that it's there.

Good Luck
Regards,
Alan

The rubber flap looking through the grill openings, note the staples.




The flap from above, looking through the hood opening.


The valance with the openings in it, the fiberglass air dam, and the black plastic air dam extension. You can see why so little air flows through the grills but must come up from below through the valance openings.


A cores upport to hood seal. The radiator and shroud are different but the foam strip is typical for your car.

7T1vette

Have you tried just changing the thermostat? That is the usual culprit in first-time overheating issues. Another concern is that you have the wrong fan on your water pump shaft (or you have the wrong shroud on the radiator {unlikely}. There should only be 1/2" to 3/4" clearance between the blade tips and the inside of the shroud. With the open clearance you have, that shroud would provide almost NO benefit for the radiator's cooling capabilities.

Try the 'simple stuff' first, before you buy expensive parts.

Since you have the radiator out, take it to a radiator shop (truck rad. repair shops are still in business) and have them check it out for leakage and pressure holding capability. $50 bucks or less, if no repair is required. If good, put it back in the car and fix what is REALLY wrong with it. Tell them it is out of an "old Chevy" [which is true]. If you mention the word "Corvette", the price will double or triple.

Ty18769

I'm sure it's the wrong shroud. When I bought it, the seller gave me the correct shroud. Since I noticed a little play in the water pump bearing, I figured I'd install the new shroud while I had the fan and water pump off. I'm now finding out just how much stuff was missing. All the seals, upper brackets, air dam, now these flaps.
I did buy a new thermostat when I picked up the water pump. It's not a bad idea to pop it in and see what happens. I appreciate the advice! But since I'm going to have it apart anyway, I figure I should try to get all the bits and pieces back in there.

Ty18769

Thanks!! I don't see part numbers for the air dam extension or the stapled on flap anywhere. It makes sense...there's a lot of open air down there. I just don't see these parts referenced for a 72

Ty18769

This looks right:
http://shop.docrebuild.com/1972Corve...FanShroud.aspx

Alan 71

Hi ty,
Added: Make certain you order the kit for a car with a copper radiator.
The hood seal and lower flap are available from the larger vendors.
Dr.Rebuild is a good source, as are Paragon Corvette Reproductions, ZIP Corvette, and Corvette Central.
Look at Dr.Rebuild's online catalogue pages 28 through 32. You'll see all the seals including the 'hood/core support air dam' and the 'lower valance flap'.
If you're going to be working on your car I suggest you send for the hard copies of the Paragon, ZIP, and CC. catalogues You'll find them much more helpful in finding parts than trying to search for them on line.
Regards,
Alan

Ty18769

Thanks again, Alan. I took your advice and got those catalogs ordered!!

Ty18769

Just a quick update,

I actually found the lower valance and the stapled on flap to be intact! I was pretty pumped. A few of the staples are still in there. If it wasn't for your pictures, Alan, I never would have known. I am, however, missing the front air dam. I do see one bolt still in there with a chunk of the old dam still on it, so that helped out in locating where it would mount! After I took some pics I went under there with some armor-all and cleaned up a bit. Pretty nasty. I can't tell if I'm missing a chunk of fiberglass, or if I just need the air dam to bolt to. Your pictures looked like your fiberglass went lower than mine goes. The chrome piece from the bumper doesn't have anything to grab onto. The air dam should solve that. Just curious.