Please forgive me but I can't seem to find a thread that is related to my issue. If one exits and I'm sure it does, please point me in the right direction.

I have a 1967 Cutlass Supreme born with a 330 and a two speed transmission. I have swaped the tranny out about a decade ago with 200r4 and a 2200 stall converter.

We pulled the 330 and had a 455 built which includes dual plane intake, hei, chrome/ceramic headers, 3 inch exhaust and a pair of flowmasters.

The ac was removed and replaced with a high volume ac that is super powerful.

The radiator had been replaced with a brand new 3 core aluminum radiator from Champion Raditators out of California.

Yes, the fan shroud is in place and secure. The mechanical fan has a new fan clutch and a 7 blade fan.

Time and tuning have been set properly.

In 100 degree temp on the highway, it will run 190 and if you turn the ac on, it will run 210. In the city at a redlight with the ac running, the needle looks more like my speedometer. In other words, you can watch the temp rise pretty quickly. The temp is moderatly high but but ok when the ac comes is off. I am certain that this is not a new issue and many of you have been here. Things that are note worthy, I am a moderate to really bad mechanic so I had people who have been doing this for their entire life doing most of the work. When I dot the car back, I noticed there is a 2 inch gap between the bottome of the condeser and the radiator. Could this be my problem?




Champion Radiators is now sending me a 4 core radiator.

 

1967 Cutlass, not 1976....that's my dislexia coming out.

 

Are you sure you have an issue at all?

You left out a critical piece of information here. It runs 190 when cruising down the highway, which is fine. It goes to 210 with the A/C on, which is fine.

When sitting at a signal light with the A/C on, it will "rise pretty quickly." TO WHAT? That's the key question. If it goes to 220, no problem. Even 230. More than that and you might want to worry about it.

 

You can edit your original post and fix this.

 

You are correct, it will go to 230 at a red light. I don't know if it will go higher because I turn off the ac and turn on the heater at 230 degree, that's as high as I'm willing to see it go. So you might be right but I don't want to take a chance.

 

I don't think you have a problem. You're talking 100 degree weather. I just wouldn't drive it in that weather, or leave the A/C off and put the top down. You could throw tons of money at it and still have a problem. Make sure the radiator is clean, the coolant is good, etc.

You live in a part of the country where you have three nice, convertible-driving seasons plus summer. Your summer is like winter in the north. We don't drive our convertibles in the winter...much.

 

We had a '67 Vista Cruiser when I was a kid, it had the stock 330, and I remember now and then in very hot weather with the A/C on, the HOT light would go on. My father would do what you did, put the windows down and turn on the heat, and the light would go off. It didn't happen often, and I don't think he ever took it to the dealer for a diagnosis. It might just have had an overly-sensitive temperature sensor.

 

Can you post pictures of the radiator area? Need to see the fan shroud, side baffles, fan-to-shroud clearance, etc.

That may help, but since it cools well at speed, and heats up at idle, it appears to be an air flow issue and not a radiator capacity issue.

 

I had a similar problem with my car with a factory a/c system running R134. I ended up putting a 16” electric pusher fan (that i had lying around) on the A/C condenser and wired it so it came on and ran constantly when the A/C was switched on. With this setup it never goes over 210 in traffic.

 

I sent it off to the body shop for some touch ups. tuesday or wednesday, I'll go take a few pics and post.

Ty

 

If you have a 50/50 mix of coolant and a 15 PSI radiator cap, the radiator isn't going to boil over until it reaches 268 degrees.
I don't think you have anything to worry about.