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Anybody else have a small block midyear with an aluminum radiator with spal fan that constantly runs hot? Im thinking of going with a BB radiator and 2 spal fans. Ive checked all the obvious stuff. Thermostat, hoses, fan operation, blockages, etc. Everything looks to be working and in operational order. Any thoughts guys?
Bought the Big Block DeWitts. Let's see how that works out.
Last edited by M3MOTORSPORTS; 08-08-2018 at 12:45 AM.
I put this in my 65 have not had a problem since. I could not keep it under 220 and did the check everything new water pump. put this rad in and fans I was out yesterday in over 90 degree and running hard
stop lite to stop lite. did not go over 180. Good luck whit yours.
1. Is the aluminum radiator a DeWitts radiator or another brand. If other brand, what is BTU/HR rating??
2. Is high temperature verifies with an IR gun or thermometer?? Or are you using the dash gage??
3. Is engine modified?? What HP??
4. Do you have a vacuum advance can on the distributor, hooked up to a "Full-time" vacuum source?? What are the vacuum can specs: i.e. what advance does it provide, and when is it all in and all out""
5. Are you running factory air conditioning or aftermarket air conditioning??
Without this information, we are only guessing...........and probably guessing wrong. Even with this info, additional questions may need to be asked.
Larry
Last edited by Powershift; 08-06-2018 at 02:39 PM.
Unless you start providing some real data this thread, like so many other "overheating" threads, is worthless and going nowhere. What's the engine configuration? OE? Modified? What is the maximum observed temperature on the gage, under what conditions and has it been verified with IR temp gun measurements. What's the actual spark advance map? Ported or full time vacuum advance, and does he VAC pass the Two-Inch Rule? What about the radiator? Brass replacement or Dewitt's repro aluminum and how old is it? What's the current installed fan? If OE or similar is the viscous clutch operating properly? What's the pressure cap rating and does it meet spec?
Guys have spent hundreds if not thousands "amatuer re-engineering" the cooling system when the problem might be as simple as a dead 10 dollar VAC. The normal operating temperature range 180-230F, and in extreme conditions like stop and go city driving or climbing a long grade out on the road in 90+F temperatures it can get into the top of this range. That is normal, for either vintage Corvettes or modern cars.
Back in the early nineties I met a Toyota marketing exec and complained about the paucity of gages (only a temp gage and voltmeter) in my new MR2 including the lack of graduated F or C numbers on the temp gage, just C and H. I told him an S-10 pickup truck had a better gage cluster than my new sports car. He explained that Toyota received continuous complaints that their cars we "boiling" when temp gage got over 200, so they eliminated the actual temp scale. Apparently GM had the same experience back in the sixties and was the reason why the mid point of the Corvette temp gage was increased from 180 to 210 and from 240 to 260 at the top end, so California customers with AIR and 195 degree thermostats would, hopefully, stop complaining about "overheating".
The average consumer doesn't understand that with a 50/50 glycol/water blend and a 15 psi cap the boiling point is 265F, and apparently a lot of "car guys" don't understand either.
Running in the 230° range. Some say that ain't terrible...but I personally don't like running that hot.
My ‘67 is set up similar to yours - small block, Dewitt’s radiator, Spal puller fan. In addition, I have Vintage Air. Going down the road on a hot day, the temp never goes above 210, even with the Spal fan off. In stop and go, it will flirt with 220 with the A/C on until I either turn on the Spal or hit the open highway.
If you’re seeing 230 going down the road, verified with an IR gun, you are at the high end of the acceptable range.
This air dam is used on the factory air cars. I learned about it from Frankie the Fink. Simple install with the clips. Made a difference in my car. I got mine from Dr. Rebuild. About $40.
I put this in my 65 have not had a problem since. I could not keep it under 220 and did the check everything new water pump. put this rad in and fans I was out yesterday in over 90 degree and running hard
stop lite to stop lite. did not go over 180. Good luck whit yours.
Who makes this radiator? It doesn't look like the typical C2 aftermarket
My ‘67 is set up similar to yours - small block, Dewitt’s radiator, Spal puller fan. In addition, I have Vintage Air. Going down the road on a hot day, the temp never goes above 210, even with the Spal fan off. In stop and go, it will flirt with 220 with the A/C on until I either turn on the Spal or hit the open highway.
If you’re seeing 230 going down the road, verified with an IR gun, you are at the high end of the acceptable range.
This air dam is used on the factory air cars. I learned about it from Frankie the Fink. Simple install with the clips. Made a difference in my car. I got mine from Dr. Rebuild. About $40.
Steve,
The air deflector that you added works even better if installed as the factory did. The flap that you have tucked between the radiator and core support should be pulled out and laid across the top of the radiator.
another way to check if your RAD is working is to check with IR gun the inlet and outlet temps, there should be 50 degree difference in the temp of the hoses the bottom one should be about 150 or so going back to the motor. this will eliminate the rad as your source of cooling issue.
Make sure you have a fresh 9V in the IR gun I had one lie to me when bat was bad
Next you can check with OHM meter what the Temp sensor is putting out, again I had a bad Temp sensor too
and last sometimes the gauge will lie to you hence using the IR gun to verify
Your issue could be as simple as a sticking, malfunctioning or incorrectly installed thermostat.
I had a new out of box Robert Shaw T-stat fail after a couple hundred miles, temp finally went quite hot on the car, and was creeping up more each time I drove it.
Who makes this radiator? It doesn't look like the typical C2 aftermarket
It a custom model to get dual fans in there. I'm not sure why the top brackets are used on the one shown because we have side brackets that bolt to the core support
It a custom model to get dual fans in there. I'm not sure why the top brackets are used on the one shown because we have side brackets that bolt to the core support
I just wanted to post mine to say the Dewitt did a great job at keeping my car running cool. It is a 65 car with a 72 nose and a 68 rad support the car is made up of many different vettes.
That is why I put that one in my car. There is not much in my car that is " normal " corvette the motor is out of a 70 Chevelle. but it is mine and I love it.
08-06-2018, 01:09 PM
Cooling issue
