V8RegistryForum.com

I have read all the posts in the Cooling section, but I have some questions. First, what I have: a 1965 Corsa with a 350/290 HP crate engine with a Deadenbear electric pump. I am running dual 1.75" aluminized exhaust tubing for the coolant lines, running through the tunnel, up through the former duct area into the trunk to an Afco dual pass 17.5" by I think 31" radiator with a custom shroud and fan from Afco. I have a wide intake air opening under the bumper, Camaro spoiler, and plan to seal it as best I can to the radiator, and plan to cover and seal the exit area (trunk floor that has been removed) I am using the Norris build as inspiration for my airflow management.
Questions:
1. What pressure radiator cap do I need?
2. I installed an air bleed in the thermostat housing, which is the high point wile the car is level on the ground and there is one on the Deadenbear pump as well. Will I need to install an expansion tank? Between the electric pump and jacking up the front of the car I am relatively confident I can eliminate any air gaps.
3 What am I missing? What do I need to consider?

Thanks... getting closer to getting this thing moving again!

John

if I am reading your description right you will have a high point where the bottom radiator hose rises up to go over the trunk floor into the interior and back down to the tunnel ,, you will need to bleed air there , my first build I ran the pipes under the gas tank so they never went up until they reached the engine , I never had any problems with air on that ,, just filled the radiator put the cap on an finished filling at the intake manifold ...the sysyem was a U with high spots at both ends ,, but my new setup goes up over the tank and thru into the interior,,there are hose splices with fittings in them , I use them at this point to let air escape there. cap pressure is whatever you feel comfortable with , I am leaning toward 16 .

Re the "expansion tank" question - interesting - I wonder if the system capacity increases (due to thermal expansion of the pipes) as fast as the volume of coolant increases due to the coolant's thermal expansion?

Seems like a good overflow tank would cover the bet, as long as everything is tight and the system can suck from the overflow and refill when it cools off.
But - it depends on where the fill cap is - and what kind of air/steam bleeds you have, and if they (and the overflow) come together at a good high point so the air can escape first into the catch tank.

I wonder if there is a good way to put one or more sight glasses into a cooling system - even if just for initial test and development?

Cheers
Jay

My system has no bleeds and runs under the floor up over the gas tank, pretty much a stock Crown set up except no filler pipe on the top rad hose. My rad 15lb cap is actually the highest point on the system as it sits now. I installed an Edlebrock billet water pump and it took some time for the system to bleed, once it did I have never had an issue with the car and it runs 180-190 max in all driving conditions even hard play or sitting in rush hour for several hours But I can see the benefit of bleeds in the system now hahaha

I notice the drawing does specify a "high point vent".
I think the main thing is - Can water get from the fill point to the suction side of the water pump?
If so, then it can draw water from the fill/reservoir, and it will push any air in the main loop back to the reservoir.

Reservoir and venting

My current reservoir is from a GM fwd car - port at bottom goes to heater hose on inlet side of water pump. (that would be the water returning from the heater core back to the motor)
One hose (about 3/8) from heater hose (port at top of motor - hot water to heater) to top of reservoir.
Another hose (about 5/16?) from hose by thermostat to top of reservoir.

Because the reservoir feeds the water pump suction side, it is pretty easy to get coolant into the engine. Air bleeds from the top of the engine back to the reservoir immediately.
The rest of the system doesn't really fill until the thermostat cracks open, then I have to feed it until everything is full.

I think I drilled a hole in the thermostat to permit some flow even when cold. Not sure if it made any difference.

fwiw
Jay