LS3 water pump rotation?

It seems like the water flow on my cooling system is opposite of what I want it to be. I want the flow to exit thru the t-stat and go to the high side of the radiator on the passenger side and return thru the low side of the radiator on the drivers side.

Just warmed the engine up to full temp for the first time and the drivers side tubes heated up first.

Anyone have a photo or diagram of how the belt is supposed to be routed? I may have it reversed.

That can cause reverse pump rotation, right?
 
It seems like the water flow on my cooling system is opposite of what I want it to be. I want the flow to exit thru the t-stat and go to the high side of the radiator on the passenger side and return thru the low side of the radiator on the drivers side.

Just warmed the engine up to full temp for the first time and the drivers side tubes heated up first.

Anyone have a photo or diagram of how the belt is supposed to be routed? I may have it reversed.

That can cause reverse pump rotation, right?
I had the impeller changed to a forward rotation this greatly simplified the belt to a sbc type. Hot tip!
 
If the pump is centrifugal it wont necessarily reverse rotation, just wont be as efficient. The pump pulley should ID rotation if its a poly vee belt, flat surface would be driven by back side of belt, grooved by vee side.
 
After some additional research it appears like the LS3 water pump does pump opposite of what I thought and the INLET is at the t-stat.

So it's doing what it is supposed to do.

Shouldn't the hot water generally enter the radiator at the top and exit at the bottom though?
 
As you discovered - your engine is rotating the pump correctly and you've plumbed the car correctly. As for inlet and outlet positions of the radiator, in an ideal situation yes you would want hot to enter from the top and cold to exit from the bottom. I doubt it makes a significant enough difference in this application to do anything about it. Make sure you're running a shroud for your fans (don't just bolt them straight onto the radiator).

Since you're in Texas the summers can be pretty brutal - I know JBurer felt he needed a fan upgrade to keep the temps manageable.

Congrats on first engine start!! Do you have a build thread somewhere? I'm always keen to learn how others are building their cars so I can be sure I'm not messing something up!
 
Cam, Thanks. I did build a shroud and have upgraded fans.

I've been thinking of doing a build thread but have not gotten around to it. But I've read all the other ones multiple times. :)
 
I’m in Texas as well. Cooling with stock fans and radiator + large air/oil cooler is marginal with a stock LS7. At speed it’s ok but not good (210-220). Around town temps will climb.
 
As for inlet and outlet positions of the radiator, in an ideal situation yes you would want hot to enter from the top and cold to exit from the bottom. I doubt it makes a significant enough difference in this application to do anything about it.

The issue is if you get air in the system (or getting the air out). If you have air in the top of the radiator and you are feeding the engine from the top, then you can have real issues.

Maybe that is why some folks have so many issues getting their cooling system bled?

If you think about an old car (with the radiator cap on the radiator), it did not matter if the radiator was only half full of water - the coolant still pumped fine. If you have a significant amount of air and pull from the top, you will be spinning your wheels...

Once you get the air out, I agree - it probably has no real effect. Especially since the top of the radiator is probably lower than your hoses at the engine.
 
Back
Top