I've got a 69 SS with a 427 (out of a Corvette) and factory air. When I'm highway driving, the A/C works fine but in town, the temp starts to rise and I usually just turn off the A/C. I assume this is typical with most 60s/70s era vehicles. However, some basic questions:

1. Is there anything I can do to alleviate this problem?

2. Is it possible to install a newer generation A/C system in older cars?

3. I have to assume the A/C designs have improved considerably over the years because my daughter drives a 90 Honda around town all day with the A/C running and it never overheats. So what's changed?

My apologies if these are too basic, but perhaps someone can point to another Web site with this info.

Thanks,
Dale

If your car has the long type compressor, and it should have, it has a real high capacity AC unit. These things are real hosses. Might need to check pressures in the AC system to see what's going on but maybe the fan isn't moving enough air through the condensor. Might take a good pressure garden hose and wash the AC radiator off real good to start with. Check out the clutch fan for proper operation. Hard to beat this factory system when it's right.

When you say the temp rises, do you mean the air gets warm or the engine temp rises? A built up 427 probably makes more heat than the stock 396, and you could be taxing the cooling system.

The engine temp is rising, as opposed to the air getting warmer.

Thanks,
Dale

Sounds like you need a bigger/more efficient radiator.

dchavez
Have you had the radiator cleaned out? Do you have a fan shroud?
rick

Suggestions above are good ones. Also, you should have a fan shroud, a seven blade fan and a fan clutch. These are essential to keeping the engine cool when running at low speed with A/C on. A/C systems of this vintage will not allow you to idle indefinitely. If that's the problem, you'll need to add an electric fan.

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Fred Aldrich
The Chevelle Engineer
Web Site: www.CoreComm.net/~faldrich (http://www.CoreComm.net/~faldrich)

my 454 equiped velle has factory A/C and temps stay ok (thanks to a new radiator with the new motor) as long as the car is moving, or not at idle for more than about 5 mins, which is usually never. So even in town it stays fine and i can stay cool, but sometimes i would rather sweat, 'cause it feels so damn good to cruise with windows down!!

I was having the same problem w/ my LS5-454. I first started with the Thermostat, then I removed the radiator, and took it to a local radiator shop and had it inspected. After a recent engine overhaul by the previous owner, there was a considerable amount of buildup from gasket sealant used form the overhaul. We figured the Stock Core was roughly 60% Plugged. We decided to just try a new 4-core (same as what the car had originally). It did help a good deal, but the car would still warm up to a temp that alarmed me, and I didn't try it but shut down the Air Conditioning when the engine temp started to exceed 212 Degrees.

My final solution was to remove the radiator once more and this time install a 3-core "Dimple Core" to my stock tanks. From what I understand this slows down the speed of travel as the water flows though the core and allows much more cooling time for the coolant, thus resulting in reducing the temperature of the engine. The guy who installed them claimed he as witnessed more cooling from the 3-core dimple core than the 4-core dimple core. He found this from just trial and error from other motors he has done in the past. He has claimed that it will drop the engine temperature, roughly 30 degrees. That's a pretty strong boast, but I guess I'll find out hopefully next week when I get the rest of my car back together and back on the road.

You might want to ask your radiator shops about dimple-core's for your car, if you're having cooling problems... hope this helps! http://www.chevelles.com/forum/smile.gif

--Jim Morrison

[This message has been edited by MY LS5 (edited 06-11-2000).]

Thanks for all the suggestions guys. Looks like I'm heading for a 7-blade fan and a radiator inspection.

Dale