[Chuck Nixon]

This past weekend with temperatures in the mid 90's and humidity high in the Fort Worth/Dallas area I drove my 70 SS 396 (with mild cam and bored .30 over) on eight trips of 30 miles each on an interstate (back and forth to a swap meet). Several times the guage read 230-240 degrees and once all the way to 250 degrees. The car has air conditioning and I had it on. Coolant level is OK and it has a new thermostat. My speed was 60-65. Anybody think this is abnormal? I don't like the idea of running at 250 degrees. One chevelle fan at the swap meet suggested I find a 68 chevelle fan shroud because he said it covers the whole radiator and mine leaves about 4-6 inches of radiator showing on the drivers side. I do have a 4 core radiator. Anybody have any ideas other than don't drive over 30 in hot weather?

 

[von]

Aside from the normal checks (Tstat, fan clutch, coolant level, radiator cap, radiator flow, etc.) check your timing and make sure the vacuum advance is functioning. Retarded timing can cause an engine to run hot. Advancing the timing sometimes helps. Also, straight water or a reduced percentage of anti-freeeze is supposed to run cooler than a 50-50 mix. You could also try the "water wetter" additive. von

 

[Chuck Nixon]

Thanks Von for the info. I will check all of the items. One fellow told me recently he found a 30% coolant -70% water worked best for him in his 69 SS 396.
I think I will drain the system this weekend and try 50/50.

 

[Tom Lasater]

Chuck, my 69 SS doesn't run quite as hot as your 70, no a/c on mine, and I've just about raged an all out war on the car to get it under control, heat wise that is. New 4 core radiator, Stewart water pump, Hi-flow Robert Shaw 160 thermostat, 7 blade GM fan, new fan clutch, (which is going back for a refund next week!), advanced the timing, retarded the timing, you name it! I think an aluminum radiator is next. Under $200 for a Griffin universal piece. That's where I'm at in the heat war. Good luck, Soldier!

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Team Chevelle Gold #33
ACES Member #02913
Chevelle Club of Michigan

 

[Chuck Nixon]

I came across a neat gadget when I took the car to my mechanic this week. He has a laser temperature reader the size of a TV or VCR remote control and he pointed it at the front of the engine by the water bypass to the water pump and it read 185 degrees and barely over 210 degrees at other parts of the block when the gauge read 240 degrees. He moved it momentarily to the exhaust manifolds and it read 400+ degrees. I am going to buy one ASAP and keep it in the car at all times. I am also going to install a set of underdash gauges to read the vital signs independently of the original gauges. I may not have been running as hot as the gauge says I was. This weekend made same 35 mile trip on the interstate and it read 215 degrees. Go Figure. thanks for your input