overheating

[dedjr67]

I have been working on a customers truck for a week now trying to solve an overheating problem, Have not been able to do so hopefully someone here has some advice.

The truck is a 65 with a stock fuel injected 350 from a 92 camaro electric fan that is turned on with a toggole switch so basicly it is always on. The car runs nice and cool (185 to 190) with ac off (Vintage air genIV) but when the ac is on temp keeps going up. I have replaced the thermostat with a 180 degree one added a second fan as a pusher to come on with ac fluhed the engine and radiator nothing seems to work. Once the ac is turned off temp goes down to normal range. I have checked my pressures in the ac system they are good. SO ac system is not overcharged. Thank you in advance for any help you can offer I am going nuts trying to figure this one out.
Dennis

[89 crew]

What are the test conditions? Is it just not able to move enough air through the coils? air locking under the hood? What are the test conditions? idle? What rpm? or are you driving when it gets hot?

[dedjr67]

It over heats at all conditions idling in the shop or running down the highway 2000 rpm 70 mph truck had one 3200 cfm be cool puller fan thought about not enough airflow so I tried putting in anther 3200 cfm fan as a pusher no change again the only time it overheats is when ac is on.

[Slmd92DIME]

My buddies 49 had some overheating problems he couldnt figure out. He took the radiator to a shop and it was plugged up really bad. Almost every hole. They recored it and it has been good ever since. It was a big block also. Just a thought if all else fails.

[joe231]

are you sure the water-pump is rotating in the right direction? does the motor have the serp. belt set up from the car? or were the pulleys changed to v-belt style? i have seen the wrong pumps installed causing overheating, there are cw and ccw ones, just a thought

[greg64]

I like the water pump rotation idea. If you've got tons of airflow, than coolant flow is the next logical problem. Also, is the ignition timing on? Retarded timing will cause excess heat (thinking about at idle). Also, have you checked the accuracy of the temp gauge? Good luck and keep feeding us info. We'll figure it out.

[dedjr67]

Water pump is rotating correctly. Timing is right on the money. I am going to send the rad out to be routed out and see what that does

[ClassicAutoResto]

I agree to try another guage on the engine. If you don't have one laying around, a new one is only about 20.00. I have seen guages be the root of the problem more than once. Good Luck!

[dedjr67]

just got the report from the radiator shop almost half the tubes are blocked so he is going to recore it and we will go from there, Guess that BG cooling system flush doesnt really work. I will post when rad comes back on monday and I get it in to let all know if it made a difference but I think that should be the cure for the problem thanks for all the advice given.

Dennis

[Fastrucken]

Hey dedjr67, How about a write up on the GENIV install. I know they don't have a kit for our trucks yet. THe genIV unit seems far superior to anything else that out right now. Im debating about swapping out my OLD Air kit for the GEN IV setup. Let ups know please!!!