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how does the cooling system work?

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warwgn

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So just hooked up my autometer gauge and it gets to 200. I am looking at the coolant and never see the flow increase? So I pull the thermostat and boil it and it does work, now I was expecting to see the thermostat open and water come flowing through the radiator? I could see a lot of flow from the heater hose into the radiator but nothing else. The radiator cap was off the whole time? This is on a big block.

I am guessing the radiator needs to be very full and under pressure and the flow goes from the radiator through the top hose and into the intake manifold and then the block back to the water pump and then back through the lower hose to the radiator to cool off?

I thought when I was a kid I could see when the thermostat opened cause water would start gushin through the radiator? Some one tell me whats up?
 
The water flows from the radiator through the lower hose and into the engine, once the coolant temp reaches the stated temp of the t-stat then the t-stat will open allowing the water to flow through the upper hose back into the radiator, once the hot water from the engine moves into the radiator and the now cooler water leaves the radiator and flows into the engine it will close the t-stat and the cycle begins all over. This is why you MUST run a t-stat to keep the engine running at a proper temp without overheating. What actually does all of the cooling is the fins of the radiator drawing heat (heat transfer) from the tubes and dissapating it into the air.

If the radiator is full to the top you probably will be hard pressed to see the "flow" through the tubes of the radiator. Because of how the system works you also won't see any flow until the t-stat opens and then it might not be open for too long before it closes again to start that cycle all over. Since you can see flow from the heater hose you know that the water pump is doing it's job at least.
 
sois it different between a small block and big block? the thermostat opens down on a small block allowing water to flow in from the upper hose, so am I supposed to mount the t-stat with the spring up on the big block? to allow it to flow from the block into the upper hose?
 
ALL cooling systems flow just as I described it. The t-stat goes in with the spring DOWN (this is the side that needs to "read" the water temp in order to know when to open based on the temp of the t-stat).

The t-stat does open in a downward motion but the water flows the opposite direction (out through the upper hose).
 
no that wont work the spring would not get hot. spring has to go down.
 
see that's what I thought too, so I should see the water flow increase when it opens. **** waht is goin on in my engine. The flow never increased even after 180. the pump works cause I can see the water shooting out the heater hose like mad.
 
warwgn said:
no that wont work the spring would not get hot. spring has to go down.
Click to expand...

4X4HIGH said:
The t-stat goes in with the spring DOWN (this is the side that needs to "read" the water temp in order to know when to open based on the temp of the t-stat).

The t-stat does open in a downward motion but the water flows the opposite direction (out through the upper hose).
Click to expand...

You need to slow down a little and read what I said. :deal:
 
warwgn said:
see that's what I thought too, so I should see the water flow increase when it opens. **** waht is goin on in my engine. The flow never increased even after 180. the pump works cause I can see the water shooting out the heater hose like mad.
Click to expand...

What problem are you having? I'm guessing an overheat issue of some sort.
 
well suspected runnin hot, the stock gauge always read about 210, but it did that with the 350 in it too, hence the autometer's. Was just watching the flow after the new gauge and never saw it flow more and the gauge got to around 195 or so, maybe just need to let it heat up more and see what happens.
 
What year is the rig and what temp t-stat do you have in it? What temp are you seeing on the Autometer gauge? If this is a FI rig then you should be running a 195* t-stat and that will usually show close to 210* on a factory gauge.
 
my brain hurts reading this

wait, what is the highest reading you gauge says? If it's a 195 T-stat, it may read 200, which would be fine. What does your T-stat say it should open at?
 
it's an 86 burban with a trans plant 454 out of a 92 burb and converted to a carb. It has a 180 thermostat in it, I am positive of that cause it was just in my hand and I read it off the bottom:doah:

it hit just under 200, thats why I figured it would be flowing more that is was. Hell I kinked off the heater hose and the coolant was just sitting there not flowing at all.
 
I'm assuming this 86 burb was an original SBC rig? Did you swap in the larger radiator along with that 454? There are other things that can cause an engine to run hot(ter) than normal and the biggest overlooked item is the radiator.
 
yep went to a huge aluminum one about 3 inches wide, and replaced the shroud to the correct one too.
 
it should still circulate the collant thought no matter the radiator:confused:
 
you're not going to see waterfall type flow out of these things, especially as mentioned, if you have the radiator topped off, if you want to see flow, drain out some of the coolant, then you'll see it flowing through the tubes.
 
yeah
radiator
constricting lower rad hose (poor quality rubber heats up and collapses)
accidentally installing reverse water pump
those are the most difficult ones to catch I think
 
that fan, if you took a newer motor and converted it to carb, hopefully you remembered to keep the original fan/belt setup installed to that motor, that flow the opposite direction like the water pump does.
 
should be the right pump, I didnt change it, the heater hose is now next to the t-stat housing and not at the back anymore, dont know if it is bypaassing the upper hose now or what?????

will bolt it back together now that the coolant is low and see if maybe it is flowing lower down.
 
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