cooling problems

[dytchdoc]

I've done some modifications (cam,intake,carb,distrib.,headers,etc.) Pushing around 350 hp now and can't keep it cool on warm days. If it's below 75F., it does fine. But above that (and this is strange) especially at highway speeds it will heat up to about 210F. At idle it's fine.(weird huh?) No emmisions, so I know its not a catalytic converter problem. I've replaced the water pump, radiator(new OEM),flushed the block, new "high-flow 160" thermostat, new stainless steel flex hose, and I'm out of ideas.I thought about an oil or trans. cooler but didn't know if that would hurt airflow over the radiator more than it would help. Clutch fan is operating properly and so is the electic fan. Have I just out-built the capacity of the OEM radiator? HELP PLEASE, I'm stumped! Out ran a stock C5 at the track last week-end though(street-tire drag). Gained a little respect for the 81

 

[drags1998]

210 is really not all that hot!!!!!! 1.does it get hotter if you go faster , or just stay at 210. 2. If it gets hotter the faster you go, try putting a restrictor in the upper rad. hose & try it again. Good Luck!!!!!

 

[Hib Halverson]

1) Make sure the temperature gage is accurate.

2) Make sure the factory front air dam is in place.

3) Make sure all the sponge-rubber stips that seal the radiator to the core support and seal the core support to the hood are in place and functional.

4) Check the radiator core once the engine is at operating temp to see if there are any spots that are colder than others. The radiator may be restricted.

 

[Glassman]

Hot

Did you try water wetter in the Radiator yet. I run a 69 built putting out 400Hp.
We ran autocross and road race, we did a driving school in the spring. The car ran hot 210 to 220 on Saturday I put the wetter in and it did what it claimed it dropped the temps 30 degrees on Sunday, 180 to 190 in 15 lap sets running hard.

You would still be better off recoreing the Rad with a high efficiency core, any good radiator shop can do it. The last one I had done ran $225.

 

[ness5353]

water wetter

Hib, what do you think of water wetter? My 72 also runs hot....

 

[titan81]

I've done some modifications (cam,intake,carb,distrib.,headers,etc.) Pushing around 350 hp now and can't keep it cool on warm days. If it's below 75F., it does fine. But above that (and this is strange) especially at highway speeds it will heat up to about 210F. At idle it's fine.(weird huh?) No emmisions, so I know its not a catalytic converter problem. I've replaced the water pump, radiator(new OEM),flushed the block, new "high-flow 160" thermostat, new stainless steel flex hose, and I'm out of ideas.I thought about an oil or trans. cooler but didn't know if that would hurt airflow over the radiator more than it would help. Clutch fan is operating properly and so is the electic fan. Have I just out-built the capacity of the OEM radiator? HELP PLEASE, I'm stumped! Out ran a stock C5 at the track last week-end though(street-tire drag). Gained a little respect for the 81

I am curious all the mods done for 350hp
please list em or email them to me if you dont mind.

 

[Glassman]

hot

How much ignition timing are you running. I mean total and when does it come in.
To much can contribute to your over heating problem. If you know the curve what is it.

 

[Hib Halverson]

Hib, what do you think of water wetter? My 72 also runs hot....

I use Red Line Water Wetter in every car and truck i own. In most cases, it's reduced coolant temperature slightly. The only case it did not was in my ZR-1. RLWW works best in engines which have nucleate boiling present in the cooling system when coolant temps are high and the engine is under high load.

SB and BB V8s can have nucleate boiling problems. The LT5, because of it's very high coolant flow, does not.

Also, there are some cars in which I use no antifreeze, just distilled water and RLWW. Those engines cool the best but require more intensive maintenance and, of course, cannot be operated anywhere the ambient temp. for parking and storage is below freezing.

 

[TWINRAY]

Are you running a "Hi-flow" water pump or a stock unit?

 

[76okievette]

Question about Red Line Water Wetter, is this something I should consided for my stock 76 sb? I do not have a over heating problem except on the really hot days, above 90, and with the A/C operating, under those conditions I sometimes get up to 200.

 

[Rudzvetz]

Anything below 230 isn't hot. There are many new cars, and have been many Corvettes over the years that run those temps right from the factory. The factory electric fan switch on the 81 turns the electric radiator fan on at 238 deg. and off at 201 deg., so you aren't even running hot enough that the fan is supposed to come on. You can get a different fan switch for your electric fan that turns the thing on at 200 and off at 185 if you would like. I know they are available from Corvette Central.


-Justin

 

[Hib Halverson]

Are you running a "Hi-flow" water pump or a stock unit?

Two of the engines have aftermarket WPs. The other engines use stock pumps.