Pushing water

I was told not to remove the thermostat but to either remove the guts or drill a few holes in it.
 
I run a 30 psi radiator cap. The reason is to keep the water from boiling in the heads around the exhaust valves, etc. With the amount of heat the head sees in a racing application I like to have the boiling point as high as I can get it.

I have cracked a block down low below where the filler is and it pushed water like you are describing. The block filler isn't a compete seal able to withstand cylinder psi so can be leaking psi into the water jackets.

If it was the pump, it would do it with the engine off and pump on, but appears that is not the case as it only does it with heat in the engine.
 
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Just had this with my mud racing truck, 5 of the 6 fire rings were broke and the head gasket was blown. I thought I had a hole in a hose, changed out the upper hose, changed my front cap (radiator is in rear), ended up plugging the pressure release port in the front as it's a pain to get too. ended up pulling the head and putting a new head gasket and fire rings in.
 
Rob. We had the block checked out by magnaflux but it could be cracked I guess.

We are going to try a 30 lb cap to see what it does and go from there. Hopefully its not the block.

Yeah not the pump for sure cause we don't run the pump when warming the truck up. But it could be heat I guess
 
You defiantly have a crack somewhere. Only reason to get that much pressure in a radiator
 
My instinct would be fire rings didn't seat right or are cracked. Have you pressure tested the system with the engine off?
 
Should be doing pressure testing today.
Have new fire rings in it. As we pulled the head to check everything our so we put new rings and gasket in.
Possible that our fire rings grooves aren't all evenly cut. So we are going to be checking that after we pressure test the system.

Wouldn't a cracked block create bubbles when the engine was running? Especially at idle?
 
cranked_dodge said:
Should be doing pressure testing today.
Have new fire rings in it. As we pulled the head to check everything our so we put new rings and gasket in.
Possible that our fire rings grooves aren't all evenly cut. So we are going to be checking that after we pressure test the system.

Wouldn't a cracked block create bubbles when the engine was running? Especially at idle?
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I would think that the hot/cold characteristics of coolant/water would be different.
 
Your leaving the coolant down 2-3 inches in the rad right? This gives a lot more de-gas area and might get you by if the leak is small enough.

I wouldn't run without a thermostat, some restriction there is your friend.
 
rad is mounted lower than the engine so we have the filler right on the head.

No room to run a thermostat either.

I am thinking that the cracked block idea is right. I do know the block has a crack in it but we sleeved the cylinders and then hard filled it. My thoughts, now correct me if im wrong is that possibly the sleeve isnt as tight as it should be in the cylinder in one spot and then that is allowing some compression gases to escape behind the sleeve into the crack and then through the hard fill.
 
Buy a napa thermostat , cut center out works good ... Without a small restriction it will not cool ... Been there done that!
 
Yeah that's most likely the culprit. Those cracks like to head for the deck and that wouldn't give you much of a seal the short distance the liner would cover.

I wouldn't be surprised if a de-gas loop and tank wouldn't keep up but might be pretty tough to fit it.
 
The thermostat wont do anything as we are not flowing through anywhere that the thermostat will be.
As you can see in this picture that is where we have our filler.

We are running rad hoses one out the side of the head below the filler then one into the block in the normal spot at the bottom of the block.

Sorry for the crappy pic but thats all i got right now
 

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Yeah I wouldn't worry about a thermostat. Most likely combustion gas is doing it. Lots of room for a de-gas setup.
 
Does the amount pushed out rise directly with load on engine, or does it take a bit for the amount pushed to increase? Or does it go up instantaneously with rpm? Or heat?

How fast is too fast to be flowing through the rad? I would imagine if its flowing that fast, that it would also be flowing that fast through the rest of the block, and not absorbing as much heat either. Maybe the rad is just too small?
 
Try resticting the outlet some. I run a screw in style restrictor that i made to fit into a an fitting. Sure helped mine.
 
Bponci said:
Try resticting the outlet some. I run a screw in style restrictor that i made to fit into a an fitting. Sure helped mine.
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I like that idea. What are the chances that OP add's a restrictor, and then increases pressure and just keeps pushing water?
 
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