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First thing I would do is establish exactly what the temp is with an IR gun because I found in my car the gauge was reading 20 deg too high. Mysteriously when I machined the sender down from 5/8 to 3/8 to fit new intake the gauge now reads correctly.
interesting. Where do you read your data points? I am indeed wondering about the accuracy of my gauge tho intuitively it seems right
Last edited by DorianC3; Apr 20, 2018 at 09:41 PM.
ASSUMING that your temp sender is doing its job correctly can be a big mistake.
(...)
I am NOT saying that all of the previous useful advice is not warranted.
DUB
This is all FANTASTIC advice. In the end, I’m looking to build a car that is dead-nuts reliable and, when possible, on the stock side. On the hottest of days I want no anxiety whatsoever.
My previous ride had electric fans drawing 25 Amps each. The radiator was the biggest lump of aluminum I could fit under the hood. The relay was an 100 amp solenoid. I forget what the resettable circuit breaker was. The alt was a custom built 200 amp. Despite that, I could never relax in that car. I was always nervously eyeing the temp gauge. My concern was the temp relays would fail to fire and I’d only notice it when it was too late.
As much as I loved that ride, I want to get away from that. The fewer things that can co wrong the better.
Last edited by DorianC3; Apr 20, 2018 at 10:00 PM.
Nobody has mentioned fan clutch. Get your car up to temperature and shut it off and try to spin the fan. If it spins more than two revolutions it maybe your problem.
As soon as saw your comment, I looked up your car and sure enough (...) GM added the electric fan INSIDE the fan shroud on the engine side in 79 to address the heat issue AND the heavy duty spoiler extension:
Fascinating and fun ticket-dodging story
Any specs on the GM fan?
now I’m not sure I want to yank out my electric fan. Then again. It’s neither OEM or GM
Here's a question then on the heavy duty cooling. What that include a triple core radiator vs double core on others. Back in the 90's my original radiator was leaking and I ordered a replacement. It was only a double core. I called the company that I ordered it from and they said their book (not yet much internet at the time) showed that was correct, but they had a triple core with the same other dimensions. So they sent that. So, with what I'm seeing on this thread it brings me to ask if this was another advantage of the L-82, 50% more cooling surface in the radiator?
The 78-80 L-82's ran VERY HOT right from the factory, mostly for emissions reasons with normal temps of 225 and 240-245 with AC on very hot days.
Here is what I can tell you about my 78 L-82 4 speed with heavy duty cooling:
1. 3 core brass/cooper radiator
2. 7 blade heavy duty fan versus 5 blade base fan
3. Heavy duty fan clutch versus base fan clutch
4. 12 O'clock 200 degree temp gauge
79/80 L-82 with heavy duty cooling had everything ^^ above PLUS:
1. Spoiler extension in my prior picture
2. Electric auxiliary fan inside shroud in front of mechanical fan (link previously)
3. 220 degree 12 O'clock temp gauge in place of 200 degree gauge
I had a friend who bought a 1979 L-82 4 speed new and traded it 1 year later since it ran HOT!
The 5 things that solved my high temps were:
1. Spoiler extension
2. Stewart Stage 2 aluminum high volume water pump
3. Dewitts aluminum radiator
4. 180 degree theromostat
5. Performance ignition timing
6. No emissions equipment
My non emissions L-82 and the rebuilt/modified L-82 (2014) 355 with 450+ Gross HP after the above changes never goes above 180 degrees now..........
Last edited by jb78L-82; Apr 21, 2018 at 08:59 AM.
interesting. Where do you read your data points? I am indeed wondering about the accuracy of my gauge tho intuitively it seems right
Thermostat housing is a good place as well as the top hose connection point into the radiator. You canals check the outlet side of the radiator to see what temp drop you are getting as the coolant goes through it.
The 78-80 L-82's ran VERY HOT right from the factory, mostly for emissions reasons with normal temps of 225 and 240-245 with AC on very hot days.
Here is what I can tell you about my 78 L-82 4 speed with heavy duty cooling:
1. 3 core brass/cooper radiator
2. 7 blade heavy duty fan versus 5 blade base fan
3. Heavy duty fan clutch versus base fan clutch
4. 12 O'clock 200 degree temp gauge
79/80 L-82 with heavy duty cooling had everything ^^ above PLUS:
1. Spoiler extension in my prior picture
2. Electric auxiliary fan inside shroud in front of mechanical fan (link previously)
3. 220 degree 12 O'clock temp gauge in place of 200 degree gauge
I had a friend who bought a 1979 L-82 4 speed new and traded it 1 year later since it ran HOT!
The 5 things that solved my high temps were:
1. Spoiler extension
2. Stewart Stage 2 aluminum high volume water pump
3. Dewitts aluminum radiator
4. 180 degree theromostat
5. Performance ignition timing
6. No emissions equipment
My non emissions L-82 and the rebuilt/modified L-82 (2014) 355 with 450+ Gross HP after the above changes never goes above 180 degrees now..........
per my earlier note, just putting the spoiler extension on dropped the temp on my stock '80 L82 without a cap or air pump, about 20 deg to, I believe 190. Now, since I stared running it again after 15 years with a retuned Q-jet I haven't seen it get to 180. I even swapped the thermostat as I thought it was defective.
My RS with a supercharger( 80 L 82 motor)had a similar issue kept running hot like that I tried different electric fans , additives , t stats , it had a brand new 4 row copper radiator at last resort I got a aluminum Be Cool Radiator problem solved! Now it runs 180-190 if I stop at a red light in hot weather it goes up to 210 for a few minutes till I move I can deal with that it used to hit 230 all the time in hot weather , with the copper radiator it never ran less than 200.
I oftentimes have to deal with Corvettes that are doing much like what you car is doing and also those with A/C that seem to want to run hot.
I do this.
1.) I remove the temp sender and install my racing temperature gauge I have to verify that the temps are what the factory gauge is showing. If my racing temp gauge confirms the factory gauge is the same. I then...
2.) Install what I have obtained is a 'fan clutch eliminator' and takes the fan clutch out of the equation and have the fan direct drive to see if the more air I am moving aids the temps.
3.) I often times install the Stewart water pump.
4.) Seeing how IF the radiator is suspect of being clogged at the bottom and not flowing correctly. I have it flow checked. Or have my radiator shop remove a tank so we can look. This is done on copper/brass radiators and the factory aluminum design...there is not much that can be done with them.
5.) Many times I may need to install a new radiator and that is IF the customer wants a copper/brass design or aluminum.
6.) Obviously all other particulars have been addressed such as proper sealing at the radiator and lower air dam and any obstructions in from of the radiator EXCEPT for the factory A/C condenser....the engine timing is correct and..
7.) I have actually removed the block drains and drained the coolant to verify that there is not a lot of old crap built up in the bottom of the engine block where the coolant circulates. I have removed these block plugs on Corvettes that swear NEVER have had them taken out for coolant service...and the amount of crap I get out of the bottom of the block would shock some people.
