weird flooding
 

Ok guys here's a weird one. Have a 383 stroker with a demon carb on it. Went out on the interstate for the first time so was up in 3500-4000 rpm range for 20 minutes (thank you 4.10 gears). Anyway, pulled off and drove the rest of the way home and everytime I sort of gunned it a second or two later the truck dies. Wait a few minutes and she fires up with a giant cloud of white smoke out the back like I flooded it.

Thoughts?

Re: weird flooding
 

Not flooding!!
Black smoke is flooding!
White smoke is coolant!
Check your coolant level.
Could be a blown head gasket or intake gasket.

Re: weird flooding
 

Mm...coolant level is fine and it doesn't continually blow smoke. That said it does have this weird thing where it will stay around 200 degrees for a long time. Then for no reason it will bump up to 240 or 250 then drop back down. Almost like a sticky thermostat except I had that replaced a couple of weeks ago.

Re: weird flooding
 

That's low coolant, or an air bubble in the system.

Don't just check the bottle, open up the radiator and look.

Re: weird flooding
 

Right at the top. How do I get an air bubble out? Drain the entire thing?

Re: weird flooding
 

I had a similar problem in my luxury sedan (Cavalier:lol:). It ran OK around town but on the highway it overheated. Coolant level OK, no coolant leaks, temperature would go up at highway speeds.

I read a lot about air in the cooling system, so I bled the air bleeder the Cavalier had and still had the problem. Went to a good mechanic and he said he was "100% sure that it is the radiator." He was 100% right. His diagnosis as not accurate, though. He said to check the temperature of the upper and lower radiator hoses to see if there was a difference, which would indicate a clogged radiator. My hoses had the same temperature after city driving. My theory is that the radiator was only partially plugged, so it was not a problem unless the engine was at high rpms.

White smoke does contra-indicate my guess, since that always means a coolant leak inside the engine, but you should have some coolant loss. Just a small amount of coolant can make a lot of white smoke.

I got a Spectra radiator from Autozone for $125 with 20% off and free shipping sale recently for my 83 C20 (that radiator had holes in it.) I scrapped the old copper/brass radiator for $30 so net cost was $95.

Re: weird flooding
 

One more theory. if you are overheating it could boil gas out of the carb, but that would normally show up as vapor lock on hot restart.