Howdy,

I've been lurking here for a few years. I'm helping my father in law keep his 62 running. He bought the car in the early '70s. It had a 350 in place of the original engine and he later (~25 years ago) found and installed a (from what I've read out on the web) 1966 327. I don't know what else isn't original.

After tinkering my way through timing and carb adjustment, both of which I now understand can contribute to overheating, it runs pretty well. Clearly now though I should have someone with a clue check that timing and mixture to make sure I'm not adding to the overheating problem.

We ordered a new Dewitt radiator for it last fall, but I haven't installed it yet. After reading through the FAQs and sticky posts on the C1, here's what I'm thinking:

1. The fan clutch and fan are probably not original. The fan is too small (1.5=2" clearance to the shroud), and too far aft (not halfway into the shroud fore and aft - completely behind the shroud). The fan is bolted to the engine, there is no clutch.

2. The radiator doesn't seem to be original, not that that really matters since I'm replacing it anyway.

3. The shroud appears to be original or at least looks like it was meant to be there.

I've replaced the temp gauge sender, and it's accurate according to my IR thermometer.

The car runs cool (160-180) anything over ~30mph, but heats up quickly at idle.

So I'm guessing part of the idle heat buildup problem is that misfit fan setup. Should I just go find an original fan and bolt it in there? Are these things even floating around anywhere at a reasonable cost?

Pics, if you're interested:
https://picasaweb.google.com/1113834...26093/Corvette

Any input appreciated. Thanks!

 

You can get properly sized fans night and day from Jegs or Summitt racing...and yes they should be 1/2 in, 1/2 out of the shroud and properly sized. Don't need a fan clutch unless you want one. You need to sort this out before anything else -- air flow is critical...

 

OK I'll focus on that fan first. Thanks!

 

diz, on a 62 it looks like this.

John F

 

Has the cooling system ever been professionally flushed?

 

The fan you have looks like an aftermarket flex fan. It is too small and not sufficiently into the shroud. Get the correct size fan and fan clutch and replace your radiator with the new DeWitt you already have and I would venture that your cooling problems would be solved. Also make sure all of the rubber air dams are in place on the sides and bottom of radiator. It looks like your heater hoses run forward through the fresh air inlet??? Plug that hole if you don't have a fresh air hose in place. As much air as possible needs to be directed through the radiator for cooling.

 

Thanks everyone, I'll replace the fan, check the rest of the shroud seals and report back.

 

Overheating@ low speed & idle is usually a lack of air flow or advanced timing. Air flow has been addressed previously. What is the timing @ idle with the VAC connected? Is the VAC connected to a full manifold vacuum and how much vacuum is there at idle.An engine needs about 26* of timing with the VAC connected to minimize exhaust gas temperature . If you have a IR thermometer measure the exhaust manifold. Normal is about 500 degrees F.

 

Where are the heater hoses going that are turned forward through the radiator support on the RH side?

 

Good call, I never noticed those hoses. They go up to a secondary cooler tied to the front of the radiator.

The two hoses connect to the engine at the top of the intake manifold by the thermostat housing, and on the side of the water pump. You can see both connections here:
https://picasaweb.google.com/1113834...69293093782530

I assume that goes as well. Am I just plugging those two holes where the hoses currently connect?

Added a couple other pics to the photos page.

I see now what K2 means, we need to either plug that hole or connect it to fresh air on the firewall. Seems easy enough.

Great input, thanks!

 

Yes, assuming you don't need the heater to work.

 

Actually I don't care if the heater works at all. I don't know the condition of the heater core, it looks like this part in front of the radiator came from somewhere else.

I've ordered a mess-o-parts from corvettecentral. If I were to remove this secondary cooling box and not hook up to the original heater core (because I don't want to get into another project right now), would it be better to connect the two nipples on the engine/water pump, or plug them? Or should I just get into the heater core now.

Here's what I have coming, if anyone sees anything grossly incorrect, let me know. And if nothing else, if these parts are correct, maybe it'll help someone else find part numbers for this stuff.

Thanks!

Product Class Item # Description Style Retail Cost Qty Extended Price
241015 RADIATOR SUPPORT SEAL - HI PERFORMANCE SIDE --- 10.00 1 10.00
241016 RADIATOR SUPPORT SEAL SET - LOWER - 3 PIECES --- 9.00 1 9.00
241017 RADIATOR CUSHION / POWER STEERING CYLINDER GROMMET --- 2.50 3 7.50
241219 THERMOSTAT - 180 DEGREES --- 6.95 1 6.95
241215 THERMOSTAT HOUSING GASKET --- 2.95 1 2.95
241308 EXPANSION TANK HOSE - TO RADIATOR --- 6.95 1 6.95
241305 EXPANSION TANK HOSE - TO WATER PUMP --- 6.95 1 6.95
241405 HOSE CLAMP SET - 327 EXCEPT AIR CONDITIONING - CORRECT WITTEK - 16 PIECES --- 20.00 1 20.00
241150 FAN BLADE - GM REPLACEMENT ( USED WITH 241151 CLUTCH ) 17 5 BLADES --- 104.95 1 104.95
241156 FAN NUT SET - TO CLUTCH AND WASHER - 8 PIECES --- 1.95 1 1.95
241155 FAN CLUTCH - WATER PUMP FINE THREADED BOLT - REPLACEMENT --- 4.95 1 4.95
241151 FAN CLUTCH - SMALL BOLT PATTERN --- 119.95 1 119.95
241202 RADIATOR HOSE - UPPER WITH TOP TANK ALUMINUM RADIATOR --- 27.00 1 27.00
241205 RADIATOR HOSE - LOWER --- 24.00 1 24.00

 

Looks good. You might want to add the petcock part which extends it out from the radiator. And do you need to replace the expansion tank cap?

 

That probably would be wise, I'll order one of those caps too. Thanks.

 

Any input on my capping or connecting the two nipples that are supposed to run coolant through the heater core? I don't know if capping them would cause problems.

Thanks, and have a good weekend!

 

The car shouldn't have issues by having the heater core connected...I'd only eliminate that as a last alternative (especially in New York). For my C1 I eliminated the fan clutch and put in a spacer (see picture) and added a 6-bladed fan. I also put the rubber seals around the front of the radiator (both sides and bottom) and then I used foam pipe insulation to close up the gaps in the radiator shroud...you can see the insulation on top of the shroud in the picture. I also forced pipe insulation down on both sides of the shroud to seal it up even more. My car runs at 180*-190* in 100 degree days at long stop lights in Orlando...its a stock '61 other than these changes.

 

Nice, thanks!

 

Thought I'd report back to close this out.

Installed all new parts except the top hose which didn't fit, sealed the sides of the radiator with pipe insulation as Frankie instructed, found and re-installed the original fan clutch, and we're in pretty good shape. It does heat up a little (up to 195-200) after coming off of the freeway and idling for about 15 mins, but doesn't go higher. And when it's idling like that, bumping up the rpm to 1200 or so for 30 seconds starts to cool it off. It didn't cool off like that before.

It's only 55 here today, so the real test will be an 80 degree day, but all in all, I think we're on the right track. Thanks everyone for the help!

https://picasaweb.google.com/1113834...92962508628290

 

FWIW

I fought overheating issues with my 60 for years..especially in parades.

then I installed an electric fan in front of the radiator and that cured the issue. suggest to install the largest you can order!

Another consideration is getting a quart of Kooldown from your local Napa that works well too! Somer Farmers use this in their equipment.



ThumperZ06

 

Well once the ambient temps made it into the 80s, the problem returned.

I've fought this issue for at least 3 years now, I'm giving up and sending the new alum radiator back to Dewitts to have their electric fan mounted.

Questions: Will the generator be ok running that fan? I don't know how much power that puts out at idle. I think I read the fan draws somewhere in the 20A range. Tried a search for that info and didn't find anything, so I assume it's not a problem with the stock generator.

Thanks again for all of the help with this. Looking forward to not worrying about temps at stoplights and in traffic. As is, we've been averaging ~120 miles/year, but I think that number will go up significantly once this is resolved.