aluminum radiator question

[Ruscal]

Originally Posted by Kaptain Kadian

I have 2 temperature probes, one that is threaded and one that is inserted into the radiator fins. I want to run the temperature probe for the fan relay in the radiator and not the intake or heads. My threaded port on my radiator is 1/8 and my threaded port is 3/8. I bought an adapter to fit the 3/8 probe into the 1/8 port, but am concerned about it getting an accurate reading with the adapter on it. Anyone else ram an adapter like this?

I am using a Derale radiator probe that has been adapted to 3/8npt. I put transistor heat sink compound on the sender/probe joint, and lightly tightened it down. (8-32 brass threads) Go easy!
Derale tech said to put the sender on the bottom radiator outlet. (coolest point)
They also said the radiator probe sometimes does not work well with aluminum radiator cores with large tubes. I decided to go with a wet sender to avoid those problems. I purchased an inline radiator hose sender adaptor. It is aluminum with 1 1/2" double barb and 1/8" NPT hole and a grounding screw terminal.
I am using the Derale PWM fan controller which has an adjustable turn on temperature set point. Right now I am fiddling with the settings to see how it reacts. It comes on at 195F, fans start slowly and ramp up to any speed to bring the temp down. Mine, as the settings are now will bring the temp to 175F at the lower radiator outlet and hold it there. The fans seem to only need to run at slower speeds to maintain that temp. They are very quiet. as they only speed up as necessary. My truck has a 180 T'stat.
The truck is still in the build stage, so no desert tests yet.
Russ