After getting my 1967 SS-350 running after sitting a few years, it seems to run hot.
Water pump, radiator, fan, and fan shroud are all original, or as was on the car in 1976 when I bought it.

The temperature gauge (that I added in 1977) indicates that it runs about 210-240F.
On a hot day (+90F) it runs about 240F on the highway and about the same on the street.

I don’t recall it running much above 180-190 in the past.

The fan is a fixed pitch, direct mount, no clutch. The fan shroud is in place and seems to be located properly. I don't see any way to adjust the position.

I have replace the thermostat with another 180F. No improvement.
I have take then radiator and had it boiled out. No improvement.
New Antifreeze is ethylene glycol about 50/50 mixture.
With the radiator cap off I have seen the following:
Thermostat opens up at 180F, meat thermometer indicates 180F
At idle, very little coolant flow.
At 1000-1500 rpm, flow seems adequate.
When rpm goes from idle (450rpm) to 1500 rpm the level in the radiator drops an inch or two.
Heater core was recently replaced, but it still ran hot before being replaced. Heater does work.

Does anyone have any ideas as to where the problem may be and how to find it?

How are you reading the temp? You mentioned a meat thermometer. Are you reading the temp guage? Any chance the sending unit is bad and the readings aren't accurate? BTW: I an ex Kansan myself. Still have family in Lawrence and Wichita.

-dnult

Have you verified the accuracy of your temp gauge by "shooting" the thermostat housing with an I.R. gun and comparing the readings? Where was the meat thermometer located when it showed 180*? (if it was in the filler opening, that's the "cold" side of the radiator). Does it spit any coolant out of the overflow hose either while it's running or after you shut it down? graemlins/thumbsup.gif

I checked the temperature by using the meat thermometer in the filler neck. The meat thermometer indicated the same temperature as the temperature gauge. I don't think the sending unit is bad since the temp when the thermostat opens up reads right at 180 F.

I do not have access to an IR gun to compare the readings.

I have not noticed it spitting any coolant while running.

I just noticed a small amount of coolant from the overflow hose. Maybe about a 1/4 cup. Not very much. I only noticed this one time. I was not too excited about this since I had slightly overfilled the radiator (above the "cold" level) so that the meat thermometer could reach the level of the fluid.

I did read in an old service manual that you could check the water pump by squeezing the radiator hose and when you release it you should feel a "surge". I have tried this, but don't think I feel a "surge" when releasing the hose.

I also didn't know if squeezing the hose should be done with the radiator cap on or off.

I am stumped!

I think your radiator might need to be cored or replaced. Even though you had it boiled out, there could still be deposits plugging up the tubes and restricting cooling capacity. If the coolant level drops when you rev the motor (as you have indicated) the water pump should be ok but you might consider replacing that too...

I would have to agree with ChopTop, I think a car that has been sitting that long has built up a lot of rust and gunk inside the motor and cooling system that will block the radiator. From what you describe, everything else seems in good shape. I would think if you ordered a new one from one of the Camaro suppliers, you would see your problem go away. Make sure that the tips of the fan blades are at least even with the opening of the fan shroud or reach into the fan shroud just a bit. This is pretty important to good cooling.

As a last ditch effort, you might try putting rain water in your radiator. A friend of mine has a water collection system. He filled his cooling system with rain water and said it ate up all the mineral deposits within a few days.

-dnult

How is the ignition timing?

Timing is around 6 BTDC, and dwell is 28 degrees

Have you tried changing your hoses? May be sucking together from old age which would account for slow down in water flow when speeding up the motor.

No I haven't tried changing the hoses because they look fine to me. I see no evidence of any hose colapsing.

I ran the car this weekend, while the outside temperature was about 80-85F. Car ran up to about 210-220F. Cooler than before, but still seems too hot to me.

I really do not want to replace the radiator since I want to keep it as original as possible, but what good is an original car if you can't drive it. smile.gif

Guess I will try an engine/radiator boil out and see what happens.

I am kinda confused.....does this car run hot when idling/slow speeds and/or cruising down the road or both? YOur answer will give us the exact path to take.

Is there ANY chance that the carb is overly lean for some reason? Overly lean carbs will cause you to overheat pronto at cruising speeds.

YOu haven't switched from red to green antifreeze lately or sometime have you?

The problem seems to be more of a highway problem. I think this because it will run about 200F around the neighborhood, but when I go to the highway, it will increase even more.

However, the increase at highway speeds seems to take about 5 minutes.

In preparation for doing an engine clean, yesterday I drained the radiator and filled with water. Warmed the car up. Directions on the radiator flush said to run the car for 10 minutes with the heater on high with just water in the radiator, drain, then add the flush. I have only done the initial run with water. During this time the outside temp was around 90F. Car ran slightly above 180 around the neighborhood with the heater on high. After 10 minutes, I shut off the heater. Continued driving around the neighborhood and the temp went to around 210F. I did not go out on the highway and stopped the car after about 15 minutes of driving.

I have not changed to a different type of antifreeze. Have used ethylene glycol.

No work has been done to the carborator.

"boiling" out does very little. Unless the shop removed the tanks and "rodded" it out, it sounds like its stopped up. Had exact same problem - as decribed - with my '68 Firebird Conv. I am local (Overland Park) & I grew up in a raditor shop & my Dad (now retired) owned the shop for 30+ years. I think between us three - we can get it nailed. Send an e-mail to me (rlwing@everestkc.net) & we'll swap phone numbers. I'm out of town this weekend but we'll hook up!