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I'm in need of a little help here. I finally got my car running but now have cooling issues. I am using a 2 core alum radiator with 1" tubes. There are shrouds both in front of radiator and in back. I uses a 16' puller fan and duct air out the bottom. The front of the car is cut open so the air intake is approx 8"x24", there are also openings in the roll pan under the bumper. Hoses are routed through the firewall, under the car to the engine. I use a high volume alum waterpump. The hoses/pipes from the radiator enter the firewall just above the gas tank. On the pipe coming from the bottom of the radiator I have installed a bleeder valve as it passes through the firewall. I'm not sure I have all the air out of the system. Here is what happens... When I fire the car up in the garage it heats up to about 195 then the thermostat open and it goes back to abt 165-70. When I shut off the key at 170 the system heats up and the radiator blows fluid out the overflow. I have a 15# relief cap on the radiator. I'm not sure the front end is high enough for the bleeder to release the air. The engine is a TPI so I can't put a bleeder in the thermostat housing. A question..... Does the bleeder need to be higher than the thermostat? Any thoughts as to why radiator overheats when key is turned off at abot 170-190. Any suggestions as to how to properly bleed this thing. Any help will be greatly appreciated
Thanks, Carl

An air bleed valve has to be at the highest point in the entire cooling system as well as after and above the thermostat. Having an expansion tank helps a lot with the difference in pressure on both sides of the system but is not necessary.

Thanks Adam, I am going to install a second bleeder just before the intake on the radiator. I hope this solves my problem

You say you don't have a bleeder at the engine because of TPI ? You might still have air in the cylinder heads. When you shut the engine off localized boiling occurs there, but the pressure build up blows out the radiator cap. No reason for water in the radiator to boil after shutoff.

Any ideas on a fix?

No experience with TPI. Looked at a couple of pics. Right around thermostat housing, you still need to do what Adam said above, higher and after the stat, but up front at radiator is not the place even though it does meet those conditions, the pipes dip down to go under the car, someone here, I think it might have been Rick Andersen posted once about jacking up the front of their car when filling system. Without seeing the car and your system here are some thoughts - does engine slope to rear about 4 degrees? if it is level or down in front raising front of car when filling would help air in heads to travel to front at stat, but then you need to bleed it out at that point before pipe goes down under car. So if you can't put a bleeder on the stat housing, you need to put one somewhere in the hose /pipe right there before it goes down. There are some aluminum pieces made to splice into radiator hoses that have fittings in them. You could braze one into your piping?

Thanks Richard, By removing the throttle body I was able put a bleeder in the thermostat housing. I have fired the engine a few times and got it to operating temp, thermostat opens and coolant flows - that is an improvement. Last time I shut it down at abt 170 it shot up to abt 210 but the radiator did not boil over, so I guess the temp increase is from coolant in the head, I have a mechanical coolant gauge in the head so it makes sense the temp would increase. Thanks again for taking the time to reply

Carl