I have a 355 that was TPI and i switched to carb. I have replaced the water pump, hoses and flushed radiator. After driving for about 10 or 15 minutes it will start to climb to 230-240 and start to boil. So i shut it off, the only thing i can think of is my radiator has the extra outlet on the top passenger side that use to go to the TB on the TPI set up so i just got a fitting for the carb intake and attached the hose there. Could this cause an over heating problem? I can add pictures when I get home from work if i am not making any sense.

 

You should be using the fitting on the cap to the overflow tank. You can block off the 2nd fitting or use it as the heater hose return. It shouldn't go to the carb. If it's on the carb you must have it to a vacuum port on the baseplate?

It was originally used to heat up the TB on the TPI because it would allow the motor to reach operating temperature faster especially when it was cold outside, thus closed loop mode.

Make sure your temp sensors are all hooked up and your fans are kicking in. If you forgot to swap the temp sensor over you wouldn't be getting fans kicking in and theres a big problem with heat build up.

Also make sure to squeeze the upper radiator hose some with the cap off the radiator and the car turned off. That will help force some of the air pockets out.

Are you using antifreeze/water mixture?

Is your air dam in place?

 

This is a picture of what i am trying to explain. The black hose going from top pass side of radiator to the intake.

 

Oh that shouldn't be like that. What you want is that one off the radiator to go to heater core if you have it still. You can usually attach the other hose from the heater core to the aux fitting on the water pump it's on the top side if you have it. Or you could hook the intake one up to a hose into the heater core and the radiator one to the other heater core side. Idea is to just get some hot antifreeze to go through the core to warm it up. If you're not running a heater you should be able to cap that off or plug it on the radiator. That's just my sugguestion I'm sure someone else will chime in.

All you're doing there is bypassing the radiator some. The coolant isn't flowing across the fins it's just piping it right back into the intake for more circulation.

 

with that hose from the intake to the radiator tank,
coolant will flow from the intake to the radiator tank to
be picked up by the water pump to be circulated back
to the engine-bypassing the radiator and not getting
cooled...
you can remove the hose,plug off where it was
connected,and drill a hole of around 1/4"in the
thermostat flange for "bypass"circulation.

 

Just plug that line make sure fans are working u might have an air bubble or 2 in there u dont mention the thermastat might want to check that getting timing dialed in and useing the manifold vacuum port helps with overheating also if everything else checks out

 

What would you recommend i use to plug the aux hole in the radiator with?

 

You might be able to find hose caps. There basically rubber hoses with a capped end and put a hose clamp around it. A small piece of hose and a bolt shoved in the open end might also work if you can get it clamped tight enough.

Are you planning on using a heater?

 

Ok i will take a trip to autozone after work today and see if i can get a hose cap. Do you know what size that would be? No i will not be using the heater. The Heater and AC have been deleted.

 

Need it the same size as the hose you're using on the connection right now if it fits properly.

 

Piece of hose lug nut hose clamps silicone done

 

I had the same type of overheating when we converted from 305 TPI to 350 Carb. I had removed the stock radiator and installed a 3 core Champion Radiator with electric fans and still could not get it down below 220. Finally reinstalled the stock air dam and that took it down to 205-210. Friend had told me that air dam forces air up into the engine compartment and assists in the cooling. In you photo noticed you did not have on. Good Luck!!

 

Without the air damn it WILL overheat. Your
conversion to carb may be contributing to
the issue. Because your car was TPI it probably
doesn't have a 'vapor return line' i'm guessing.
This could be an issue with carbed motor as it
was with mine. My car was always carbed and
came with mechanical fuel pump WITH vapor
return line. After upgrading to a performance
fuel pump 'holley', it started overheating.
These pumps do not come with vapor return
line so fuel sits there heating up 'vaporizing'.
This caused the temp to shoot up quickly on
hot days. Once i found a performance fuel
pump with vapor return, problem solved.