Hot Rods SBC puking water .....resolved

For what it is worth.....this engine is on it's second camshaft. The first went flat within about a half an hour of run time so the engine came out, dis***embled, cleaned, new bearings and this time a roller cam. The first time the engine was fired (with the flat tappet cam) it came up to 180 degrees on the gauge...not like now where it after reading multiple posts on air in the system, the gauge barely gets off the peg. Using a roller cam now.
Here is a picture of the two thermostats I have used, they both appear to be the double sealed type used in "recovery" systems.
I am almost resigned to draining the system and taking the radiator back to the shop and have a fill added, which was what I wanted to start with. @squirrel thanks for the pictures of what Corvettes actually used...not sure where I got the idea that the type of fill I was using was a Corvette thing and yes......wish I'd have went with plain water to start with

 

So if you let it set and run at a fast idle, does it ever stop puking coolant? If it does stop puking, it might be as easy as doing this and then driving it and see what happens. If it doesn't overheat you are probably good to go.

I would let it set until it cools completely and see what the level is in the overflow tank. If it is dry, you might want to add some coolant, maybe half full and repeat this test. Keep doing this until the overflow tank has some coolant in it after the engine has cooled completely.

If it never stops puking coolant while running at a fast idle, you have some other problem. But, you need to try this first.

 

Every cooling system will expand and coolant levels will rise as the coolant heats up. I always start up the engine after adding coolant with the cap off to watch the level, and ensure the system is full. Many will drop coolant level when the stat opens, and then you can top the radiator off, but once you top it off and temp continues to rise the coolant level will rise also if the cap is left off. So once it begins to rise after topping it off I replace the cap to let it build pressure.

 

Had one puke.
Every time the t-stat opened.
Bad cap

 

I think my initial pictures may not have given proper perspective on the location of the fill neck in relation to the upper radiator tank.

 

Those 2 caps are both recovery caps [which is what you need]

But they will not work on your system until you get rid of the air-lock in the system.
A recovery cap needs vacuum from the water cooling to syphon coolant back from the bottle.

With your present system ,the air-lock will compress when hot and contract when cold resulting in no vacuum.
Water does not compress, so it expands to a point where air pressure and cap pressure get to a point of equilibrium.
Above that expansion point the air will not compress any further because the cap will open and release further water expansion [it wont release air because the air is trapped at the highest point]

Also note :Corvettes and FE Fords do not have a recovery tank! It is an Expansion Tank [basically an expansion tank is a remote upper radiator tank] that is used when they need a higher fill point.
An Expansion tank will still puke coolant if overfilled ,similar to older type non recovery systems

A Corvette type expansion tank costs $300 [and you still need a hosetail at the highest point in the radiator] So it will be cheaper to add a 90° filler neck.
You could simply shift the radiator hose outlet up to the highest point [but it would be easier to leave it alone and add another filler neck.
NOTE: please rotate your fan and mark a No-Go-Zone on the tank so that the fan will clear the filler neck [you might need to add this to the p***enger side between the tank and the alternator]

Also to check the water pump on your engine , leave the engine idling with the cap off until the thermostat is open [keep topping up with water] You should see the water flowing towards the radiator


Your cooling system problems are an easy fix [compared to other issues hot rod builders face] it is not a major problem to pull a radiator out [and the remedy is cheap] .
Even the water pump can be swapped if it was the wrong "reverse rotation" [water pumps are cheap]

 

Thanks @Kerrynzl for your suggestions.
I dug out an old short water pump and installed it. If the first pump I used was a reverse rotation pump I will have solved the problem. If not, well??????
I found that it uses a different bolt pattern on the water pump pulley The only water pump pulley I had was too large of a diameter and interfered with the crank pulley so I used it as a pattern and drilled the pulley I had used before so everything lines up. Filled with coolant and called it a day (we quit at 9 PM)

 

If the old pump was reverse rotation, you have only solved part of the problem.
[it is a step closer]

Pull the back cover off that pump and have a look.

Here is a short video on how to tell the difference


The air-lock is the cavity between the 2 red lines. The fill level is the blue line [where the cap seals]

 

Had to resolve some other issues but............the problem seems to be fixed and it all went down to burping the air out of it. I jacked the front end up and filled with antifreeze (there was an eighth inch hole drilled in the thermostat but it is so loose that the water flows around it...and there was just a thread on that issue a few days ago) and did the "burping" and I've driven it a bit and so far haven't had any issue. I'd changed water pumps, that one leaked, so I went back to the first one, the temp gauge shot ****s so had to buy another one and the thermostat housing is still leaking..those rubber O rings seals just ****. I will be buying a new O ring shortly.

This morning I called one of my cl*** mates (we have been out of school for over sixty years) and in conversation I asked told him about my problem and asked him if he ever had to "burp" a cooling system. He couldn't remember having done so but..........he has the same answer for lots of my questions...I don't remember

Thanks to all of those that offered ***istance....and the next build I will just use water until I sort all of the problems out...then maybe everything will go right the first time!

 

My 96 Impala SS needs burping anytime the cooling system is opened up.

 

the top pulley is the same just a bit off on the holes which can be opened up to fit with a die grinder. also some of the later short pumps have both patterns drilled and tapped in them.

 

Also the vent tube on your overflow tank looks too small. That will cause coolant to spray out in the air under normal operating conditions. I learned that one the hard way.

 

My '96 Roadmaster has the same LT-1 as your SS and needs burping as well. But GM included that nice little bleeder valve at the high point in the system so it makes it real easy to bleed out the air.

 

Just trying to add something to the mix,,:

Take a LOOK at an original 1940 radiator,,

what to you notice? Somebody throw a picture up here, Please...