Don Terrill’s Speed-Talk

I want to fill up the engine with coolant. Rad is lower than engine with an overflow tank.

What is the best way to get the air out of the engine as much as possible ?

BTW : Stewart thermostat, additional cooling lines to the center of the heads.

I realize that this may be a simple idea, but , can you lift the front of the car high enough that the top of the rad is higher than the engine? I have no idea just how much lower the rad is compared to the engine. Just an idea

Holden got round this with a bleed screw in the top of the water neck in the block (the highest point of the system).

Perhaps run something similar, determine the highest point and drill and tap a hole to run a bolt. Fill radiator and overflow, then run engine till starts to warm and shut down. Loosen bolt until air starts to escape. When coolant starts coming out, re-tighten bolt. CHeck overflow and keep fluid in it as engine cools. Repeat a couple of times and should be good.

I've never used or seen it but one of my customers has a vacuum operated coolant system tool that bleeds the air out. He says it saves me lots of time, no system burping necessary.

Loosen both center cooling lines. Rig up something taller than these lines at the radiator cap and fill till the coolant comes out at the lines. Plan be fill the system as much as you can from the cap and then back fill from the center cooling lines. You could put coolant in one side at the lines until it comes out the other side but make sure both are purged of air. I have a Corvette that has the engine higher than the cap, pain in the butt to get filled correctly.

Hi,
Adding A Air Bleeder At The High Spot. Drilling A Small Hole (1/8") On The Side Of The Thermostat Will Help Air Pass As You Fill.

There Are Radiator Hose Couplers That Have A Radiator Cap On It That Can Be Sliced Into The Upper Radiator Hose. Not Pretty But Works. I Have Seen Thermostat Housings With Radiator Caps On Them Also.

Good Luck

If you have a thermostat valve installed would be good drill 3 to 4 1/8" holes on it to aid with system fill and engine cooling.

Looks like the beast is almost ready to come to life??? Keep us posted.

BrazilianZ28Camaro wrote:If you have a thermostat valve installed would be good drill 3 to 4 1/8" holes on it to aid with system fill and engine cooling.

Looks like the beast is almost ready to come to life??? Keep us posted.

Yes, body was put back on yesterday after a looooong time.






Yes, Robert, these vettes are a PIA to get all the air out the system. I have an extra plug on the thermostat housing. that seems like the highest point. Will leave that open.

Do I need to disconnect the 2 center cooling lines ? Are these prone to having air in them ? The normally are lower than the radiator.

It's just a good place to let air escape.

Very nice restoration, I liked the crankase evacuation system.

BrazilianZ28Camaro wrote:Very nice restoration, I liked the crankase evacuation system.

Couldn't use the original one, since I'm going to run ITB's in the future and after break-in. Hopefully it gets enough vacuum. With the carbs I get to test it thoroughly.

Using the vacum fill will work, but when you remove cap fluid will come back out, like others said install bleed plug in thermostat housing, but you will have to put your recovery tank above the thermostat to allow a positive pressure fill when engine cools down. it will take a few cooling cycles to get all the air out. and do not take it on road trip till you do it. I've had other corvette owners over heat engines on the first road trip because they didn't listen. I would bleed the air out in front of them in amazement.

All the ways suggested are good. I can add that most all radiator caps have a pressure relief valve as well as a vacuum valve. If the cap is functioning properly. The vacuum valve is designed to deal with that issue. Every time the engine cools down the air in the system shrinks causing enough vacuum to suck more fluid up in to the higher regions and will hold it there until the next heat cycle. After a few cycles. As long as the cooling system is totally sealed as it is supposed to be. It will bleed all the air out and self fill above the radiator level and will have purged the air out through the over flow bottle.

If this was not designed to do this. Most people driving vans would freeze in the winter with empty heater cores.

So a little patience and a good rad cap will probably do the trick. Those vacuum fill kits work very well. Would definitely speed up the process.

I would use a vaccum fill they work real good, maybe some one will let you borrow.
Does't intake have cool passage drilled for temp. senor etc. bleed there.