So i just got done build my 383 and it runs super hot according to my guage. I mean 230 240 while driving but 210 idle. Its a brand new raditaor but stock size is it to small. The motor has alot of work done and the stall is 3600 with a th400 so it screams a little bit. Put electric fans on and didnt help at all. What do you guys think. I burped the system to.

 

Its not going to be putting off very much heat at idle.
What is your thermostat?
And do you have a coolant bypass?
Is it correct to assume you have cooling system pressure?

 

the stat is a 180 and the heater core and ventilation system is gone so its water pump rite into the block hose.

 

I have similar issues. Firstly, the 383 puts out a lot more heat than stock, and the stock fans don't turn on until well over 200 degrees. Hopefully you have replaced the 195 thermostat (stock) with something cooler. But perhaps your greatest problem is you stall converter. These create HUGE heat while in gear, and this heat is transferred into your coolant via the auto trans cooler built into the radiator.

You will need to upgrade your radiator, go with a thermostat about 170 (180 max) use a cooler fan switch or just set your fans up to turn on much earlier, and remove the trans cooler lines from the radiator and run them through a dedicated trans cooler (use the "radiator" style, not the 'tubes with fins" style". If you do all the other stuff, you might not need to upgrade your radiator, but it's still gonna run hotish in traffic.

TA

 

do you have the deflector in place under the radiator?

 

Sounds like you need a bypass.
When I turn off the valve I installed in line to the heater core it causes all kinds of strange over heating problems on the high way. Then when I open the valve, its works fine.
You need lots of coolant flow even when the engine isn't putting of a lot of heat. That keeps heat and hot spots from building up.
Plus I think the thermostat alone has trouble flowing the standard 37gpm.

 

I dont have the trans lines going tinto the radiatior they are on there on to a trans cooler with a fan. The electric fans are also controlled by a switch i put in so i turn it on as soon as the car starts to keep cool. The stat is also already a 180. What is the by pass you guys talk about though. I no longer have a heater core in the car.

 

I repeat, do you have the plastic air deflector under the radiator installed?

 

You need 3 things to keep your engine cool.
1 good air flow at different speeds
2 lots of coolant flow even when not fully hot
3 cooling system pressure

If you cant control your cooling system temp you wont have any cooling system pressure at normal operating temp. If you want to be 180ish and you heat up to 230'F and cool back off to 180 you will have little if any cooling system pressure.
Your cooling system will work much better if you can keep it pressurized at you target temp.

 

i do not have the bottom piece for the extra radiator airflow and can not find one anywhere

 

Ebay, i remeber seeing tons of NOS ones on there, they may still b available from GM, otherwise, Classic Industries has a camaro catalog that has TONS and TONS of repro stuff for our cars, brother bought a 69 and told me to check them for seat covers and they r the only one iv found so far that has them, not even YearOne had them last time i checked. plus the catalog is free, pick it up.

 

I think most people who need an air deflector just make one out of what ever they have laying around.

 

i made an aluminum one, made it almost 2 inches shorter then the stock one and at more of am angle to the front, it was a simple fabrication job.

 

Well theres your problem. Get one ASAP. Everyone sells one. Doesn't sound like you looked to hard, lol.