LS cooling question..
 

Hi guys.

A question regarding cooling of LS engines.
My current setup is a LS6, with a CR racing radiator and dual 11" SPAL fans, 160F thermostat and a LS3 water pump. More than enough cooling for my setup.

However i am having cooling issues when standing still. The hot side of the radiator is hot, and the cold side is more than cool enough. This makes me belive that my fans and radiator is good enough. Without a thermostat in, it runs too cold 150ish. Which leads me to a faulty thermostat but this i my third one...

I have attached a great photoshopped picture of my setup with cold/hot arrows. My consern is that the radiator is delivering cold water to the thermostat and therefore the thermostat will stay closed, even if the engine water temp is increasing.

Any suggestions?

https://lh3.googleusercontent.com/nx...U=w672-h895-no

Isn't the temperature sensing element of the thermostat on the hot side of your pic?

Don

The part of the thermostat that reacts to the temperature is on the back side of the "valve" away from the cooler fluid. The engine side is hotter & opens up to allow cool fluid through, it closes if temperature drops, recirculating warmer fluid from the engine back through it. I would say you have a bad thermostat, but you say you are on the 3rd or 4th one. So i'm confused too.

Is it possible to install an LS thermostat backwards?

Don

No, the metal coil that controls the valve wont fit under the housing if backwards.

Ok, thanks for the replys.
Ill try some other stuff tomorrow.

I am still thinking that when the thermostat opens, cold water get to the "temp sensing" side of the thermostat, which in turns closes the thermostat.

Does the backside of the thermostat (passage to the heater) need alot of circulation of hot water to get the thermostat working properly?

I don't think this is it. The thermostat is more efficient if you have your heater hoses flowing full time as opposed to a shutoff valve in them. This is how all LS motors work from the factory. However, plenty of people run the ports blocked without any trouble.

I suspect air in the system. Where does the steam vent line go? Next time the car is fully warmed up and you are sitting still try reving it up above 2,500 rpm for 30+ seconds. If the temp drops then you have air trapped in the system.

How are the fans controlled? What's the temp when you're standing still? Why a 160* thermostat?

Where did you connect the steam vent?

Don

If this was the case every LS out there would have this problem. They don't...

Don