Langadorf

Now that it's summer time, I'm having some overheating issues again with the vette. I have a fairly new aluminum LT1 radiator (1.5 years) sealed around the edges, dual electric fans sealed to the radiator, a 160* stat, and a Meziere electric water pump flowing 35 GPM. There are no leaves/junk obstructing the radiator. For a while the temp sits at 160 and then slowly starts increasing. If I'm at steady cruise on the highway, the temps seem to level off at about 200. However, if I pull off on to side streets the temps will jump up near 220 which is when I pull over and shut it down.

This is not the first time I've had heating problems. Originally I had the stock mechanical LT1 water pump, the same radiator and fans (all unsealed, however). I would experience this overheating problem at idle/low speeds, but on the highway I would actually run a bit on the cool side. When I took my heads off to get ported, I made the change to the current cooling setup.

Any ideas on what is causing this problem and what I should do to fix it?

Thanks

Desertdawg

For your reference. I drove my 82 last week, outside air temps were about 115 degrees, Mine has a 195 thermostat. Just cruising along I run about 210. if I push it the temp stays there. In traffic and stopping at lights, It will creep up to 220 to 225. This is nothing new for us out here. so unless you see over 230 I wouldn't worry. Just keep good oil in it.

Also the 82 has an oil temp gage, It runs about 240 cruising easy. If I step on the gas, say running up to 80 or so. The oil temp will climb to 250. I usually let off about then. No need pushing my luck. Especially when I'm crossing the desert and the nearest civilization is 30 miles away.

Langadorf

At what temp do you start to risk blowing head gaskets/etc?

If these temps are OK, my car still runs crap when it gets this hot. I think the fuel in the carb bowls might be boiling. This is even with a wooden spacer.

Any other ideas/comments?

BSeery

I never liked the idea of the electric water pumps. Do they flow enough? I know they are ok for drag racing, but that's pretty easy stuff compared to cooling a car doing 80 MPH down the highway.

Desertdawg

If I blow a head gasket, I will let you know at what temp it happens. :lol:

As for the fuel boiling. I guess that since my 82 has fuel injection. I don't have to worry about it. You could try a higher pressure fuel pump I guess.

jerryp58

:iagree: 220 in traffic on a Texas summer day doesn't sound that bad to me.

But...
What temp do the fans come on?
Since the problem is in traffic, can you upgrade to higher CFM fans?
What about an oil cooler?


[Modified by jerryp58, 5:45 AM 7/13/2003]

Langadorf

The fans are always on and they seem to pull alot more air than the stock mechanical one.

Would an oil cooler really help that much? It wouldn't seem that I should need one.

I can always switch back to my mechanical, but like I said, I still had problems with it too. Also, all the guys in the C4 section swear by that particular electric pump (even for daily drivers), so I would think it'd be alright.

isosceles

I've had cooling issues in the past too, and read many threads about it. Looks like the only things that haven't been addressed in this thread are :
is the radiator cap holding the proper pressure?
is your timing retarded (or at least not advaced enough)
I'll also throw in coolant type. Stewart Components recommends running water and a bottle of cooling system lube such as the ones from Prestone or Zerex if you are not in a freezing climate. According to them, water dissapates heat better, which makes sense to me since it is so much less dense than antifreeze.

edit: I can't believe I had to edit "retarted".. I must be.. well, you know :D


[Modified by isosceles, 4:21 PM 7/13/2003]

Taijutsu

I hope these temps are w/AC on? If not you've got real problems. I solved my overheating problems in stages. First I got an oil cooler, that helped. Then came the proper 7 blade fan and clutch eliminator. This allowed me to run AC in summer. 1.6 roller rockers lowered twemps 15o and made the sweet spot 200 rpm higher. Last I had the rad rebuilt from 3 core to 4 core and added dual spals. Now I run AC on 100o days and never go over 200o. Hope this helps.
Rick