LS1 cooling system design question
02-26-2007, 02:51 AM
#1
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LS1 cooling system design question Since the LS1 is a 'normal-flow' cooling system (inlet-cylinders-head-outlet), I don't understand why the thermostat is located on the inlet side of the pump. This means that the thermostat is opening and closing based on the temperature of the water coming _out_ of the radiator--after it's been cooled.
But the temperature readings that the ECU/dash take are from the cylinder heads. What this means is that the water in the heads could be at 200F, but since the thermostat is seeing the post-radiator temperatures, it may only be seeing 170F.
This seems like an odd design. In most other cars, the thermostat is directly after the heads. So when you say 'a 180 degree thermostat' it means the thing is open when the hottest water in the engine reaches 180. But in the LS1, it means that the thermostat is open when the _coldest_ water is at 180.
Why?
(The reason I ask is that I'm planning to use an aftermarket PWM fan controller, and I want to know where I should be taking a temp reading so I can make sure the fans work correctly with the t-stat.)
-ch
But the temperature readings that the ECU/dash take are from the cylinder heads. What this means is that the water in the heads could be at 200F, but since the thermostat is seeing the post-radiator temperatures, it may only be seeing 170F.
This seems like an odd design. In most other cars, the thermostat is directly after the heads. So when you say 'a 180 degree thermostat' it means the thing is open when the hottest water in the engine reaches 180. But in the LS1, it means that the thermostat is open when the _coldest_ water is at 180.
Why?
(The reason I ask is that I'm planning to use an aftermarket PWM fan controller, and I want to know where I should be taking a temp reading so I can make sure the fans work correctly with the t-stat.)
-ch
02-26-2007, 10:54 AM
#3
well, the tstat will start opening at 180. I would not worry about not measuring from the same spot as the tstat. Just take the temp reading at the cylinder head - since all stock setups are using this place with the stock ecu, you can't go wrong. you can always adjust fan on/off settings to your taste later on.
