doorgunner

Exactly! Last year I changed a head gasket on the '34 truck350 SBC. I rounded the tops of the head-locating-pins so I could re-install the head without removing the intake manifold---I did replace the intake gasket though.

It wasn't that bad to change the gasket (no A/C...no emissions)....but I really didn't want to take the Corvette engine apart because of overheating....it just plain runs too good to "mess with it".

I'm trying to document EVERYTHING that I do in case another rookie has a similar problem with overheating.....

AT LEAST HE' LL KNOW WHAT NOT TO DO......LOL!

AND FOR THE SENIOR MEMBERS/EXPERTS......THIS THREAD OUGHT TO BE GOOD FOR QUITE A FEW LAUGHS!!!!

mds3013

Too much to read through. I will tell you what I know. With the radiator cap in place on the radiator and the engine at operating temperature the upper hose will be hard as a rock and hot. You may well have the same problem I had. Not enough cooling capacity from my stock 35 year old radiator. Even though it was not leaking it was not adequate to cool the engine even back in '83. Dewitt's solved the real problem. Stock radiators were short on capacity when new. Could you maintain 210 degrees and cycle the fan clutch on and off again and again? Yes. With the Dewitt's I can run the A/C in 110 degree ambient temps., maintain 70 degrees inside the cockpit and hold 180 degrees water temperature all day long. mike...

doorgunner

Thanks Mike.......you guys are ganging up on me concerning a new radiator!

(But I checked the '34 truck 350SBC and the Escalade 6.0L engines/the hoses were not baseball-hard at operating temperature/I could squeeze them almost together. I had to pump up the radiator pressure tester to 20+ lbs. to get the upper hose as stiff as it gets when driving the Corvette)

Haggisbash

Many years ago I bought a car that had a reconditioned engine and then found out it ran hot, all appeared okay when I test drove it but I found there was no thermostat fitted! I subsequently fitted one and found the temp stayed consistently high, I kept the car and drove it for a couple of years but when I sold it the next owner drove it harder than I did and I think cooked the motor. I heard that they found the crankshaft was bent which was the reason for the hot running.

gbarmore

Interesting post doorgunner, I have an overheating issue on my '80 as well, and the similarity we have is that my top hose is rock hard as well. I thought this was very odd because it seems to indicate a bottleneck somewhere in the system, right? What I did find out through experimentation is that if I leave my heat selector in the HOT position which opens the heater core to coolant, my engine runs right at 200* all day. If however I slide the heat selector to cold (doesn't matter if the heater box fan is on or off) my temps begin to jump up immediately and will not stop until I slide it back to the hot setting. So when I close flow to the heater core I get overheating really fast and really bad. Have you noticed any correlation to your heat / cool selector settings? I have a brand new Dewitts, dual Spal's, new motor, hoses, etc. Basically everything in my system is brand new.... Looking forward to hearing what finally solves your issue.

doorgunner

Thanks Men.......the engine has no vibration for a bent crank.

A new Dewitt's and it still overheats....that sucks!

We will figure it out sooner or.................LoL!

76CSRvette

did you make sure to flush engine before installing raddy. I had nightmares because of the raddy stop leak stuff clogging new lines. I went through 3 raddys before the dewitts put a stop to my nightmares on third one we opened it up and cleaned it found out before rebuild they used that stuff clogged all rads. Did you try restrictor plates instead of thermostat.

76CSRvette

did you use a thermo/temp gun to verify your car is actually running those temp or an extra temp gauge. My fans are electric and the switch to turn on fans is 185 and my gauge shows 200 when fans start. I tried like 5 different send units before I was comfortable with the corvair unit as it was more consistent. I also added a separate tranny cooler to keep heat out of water from tranny.

doorgunner

'76'...".I was amazed to see that the infrared gun measured within 1 degree of the Corvette temperature gauge! I took other readings that "messed with my little mind".......

For example, the top of the air cleaner measured only 10 degrees Higher than the ambient air temperature.......among other bizarre readings/check out the "Interior Heat" thread.

doorgunner

On a sidenote........the top radiator hose no longer gets too stiff to squeeze....(while I had the cooling system apart, I replaced the top hose because of the overheating)....apparently, like you guys thought, the radiator was partially blocked causing the coolant to build up too much pressure.

I did what you guys recommended and replaced the original radiator with a temporary 1" aluminum radiator. I temporarily tie-wrapped everything in place to test the set-up and see if it would solve my problem(s) before I bought brackets to permanently mount the "new to me" radiator......



It really goes well with Bubba's 1" angle-iron radiator support......!





Rats......the gun reading didn't show-----it should read 195* before the thermostat opened.......





Annnnnnnnd 180* after the thermostat opened.......




I won't wrap the wiring or touch up the ductwork with satin-black until I drive the car tomorrow and test the aluminum radiator..

Brack c

Hoping this solves your overheating gremlins DG

doorgunner

O.K. Men.........................it worked! I drove the car for one hour in town and on the expressways-----NO overheating.........ANNNND I could actually squeeze the upper radiator hose without needing channel-grip pliers!

I continued driving for another hour on the freeways----50 to 70 mph----NO overheating!

The heat gun and dash temperature gauge both read 180* no matter how hard I drove the car. or no matter how many traffic lights that I encountered.

I now have a 50/50 coolant/water mixture and "water wetter" since there is no more boil-over.

Tomorrow I'll try to get some audio/video when I take the car along some of the country roads.

So.................thanks to everyone for the input