shbox

Yes. I don't know how the red and blue arrows and their direction could be more clear.

koolaid_kid

iTrader: (21)

What movie was that "What we have here is a failure to communicate"?
I suspect an age-old thought pattern is at work here; water must go into the radiator at the top, fall down the radiator tubes to the bottom, where it is sucked back into the engine.
Not true on a reverse flow engine, just think backwards.
Try a different thought pattern; AFAIR, the decision was made to cool the heads first, since they contain the combustion squish zone where all the heat is generated. They thought this would remove the most heat possible, versus the old pattern where the heads were cooled last. So the coolest water, that which has just exited the radiator, hits the top of the engine first, which means it has to come from the top radiator hose.
Hope that helps.

the_merv

iTrader: (88)

That'll work I guess..lol

jaycenk

iTrader: (1)

OK then I am on track lol It is completely backwards to me and I thought the cooling was just backwards in the block and heads. My apologies to everyone for the drawn out thread and confusion on this topic. lol made for an interesting experience. Thanks for all the help Merv and shbox, I stand corrected.

the_merv

iTrader: (88)

It's all good..we're here to help.

Spartan7

iTrader: (7)

I understand the reverse cooling system. I understand the thermostat is a 2-way stat, as opposed to the SBC one that only controls one direction of flow. The only part that is throwing me off is the thermostat. Is there a bypass or something that will allow coolant to pass through it into the WP?

Right now, the way I understand it, on a cold start the thermostat will be closed. The WP is pushing coolant through the block and back to the radiator. But with the thermostat closed, how does it draw cooler coolant from the radiator?

Oh, and Shoebox, if you could post up that cutaway for the WP or send it to me, I'd love to see it. I'm always up for new information.

the_merv

iTrader: (88)

With the Thermo closed it stops Coolant flow from the Radiator..that's what it's designed to do and why it's there. The WP is cycling it around the Engine till it warms up enough for it to open, then it lets whats in the Radiator in.

fuel

iTrader: (13)

so what do you guys think of this gus new fill cap location.........im doing a radiator relocate to but with a smaller race radiator ......https://ls1tech.com/forums/lt1-lt4-m...brication.html

markeheiden

OK this thread has me completely spun around. I am about to plumb my new LC9 conversion and I need a straight answer too.

Does the water flow on an LS motor come out the BOTTOM of the water pump thru the thermostat into the BOTTOM of the radiator, and push UPWARDS thru the radiator and out the top on the opposite side of the radiator and return to the top of the water pump?

If so it is entirely backwards from all previous engines I have seen. EVERY other engine has the hot water flow out of the engine thru the thermostat to the TOP of the radiator and down to the bottom where the cooled water returns to the engine with NO restictions.

Someone please clarify before I plumb my new engine wrong and cook it!

Oh Yeah and before you say it, I understand what "reverse flow" means and why they reversed it thru the engine/heads but not why it would ever flow from the bottom of the radiator to the top?

Thanks!

firehawk238

iTrader: (1)

its called reverse flow because the coolant passes through the cylinder heads before the block while a GEN 1 sbc the block gets the coolant first, and the heads get cooled with already heated water. that is why its called reverse flow. it does not actually flow exactly reverse.

your coolant inlet comes from your bottom radiator hose. the upper hose and your "water outlet housing" (where the thermostat goes) is where your coolant that has already passed through the engine makes its way back to the radiator. the reason this is your outlet and is where the thermostat is located is because the engine circulates coolant even when the thermostat is closed until your engine reaches 180* or 160* depending on what thermostat you use. when the stat upens it allows the hot coolant to flow back to the radiator, and fresh, cooler coolant to make its way into the engine to cool it back down.

the_merv

iTrader: (88)

The part with the Thermostat is the Inlet..run a Hose from the passenger's side of the Radiator to that. The other part on the LS Waterpump is the Out..run that to the Driver's side of the Radiator.

The LT1 Radiator is actually thicker than the one for the LS1..just don't forget to plug the little 5/8 port on the lower Drivers side..the LS1 doesn't use this.

markeheiden

Hi Merv, My question did not address passenger or driver side. On my radiator the bottom outlet is on the pass and top is on the driver side.

My concern is that as you described it, the water comes into the lower part of the water pump from the bottom or cool side of the radiator into the thermostat housing.

This is exactly backwards from conventional flow where the hot water comes OUT of the thermostat housing into the TOP of the radiator to be cooled on the way down.