Location of Thermostat for electric fan?

[AnthonyG]

I installed an electric fan and put the thermostat surface mounted on the radiator with poor control results. Fan on/off wasn't reacting fast enough and engine would get too hot before coming on. Got a tip to install the thermostat inside one of the hoses to the radiator. This works great for fan on/off coordination with coolant temp. but can't seem to stop slight weeping of coolant out of the hose where thermostat wire was slid into the radiator. See pic's. Anyone had this problem?
Ideas?

[Thaplumbr]

On my 59ab I pulled a plug on one of the heads, and put it in there, I wanna say it's 3/8 npt, did the same on my dads 8ba both stock heads.

[scicala]

When I worked in engine dyno testing, we used to put a little RTV around the thermocouples when we slipped them under the hoses. Seemed to work fine without leaks if you do it right. Of course the best way is to use a fitting close to the radiator top hose. The dyno setups were temporary, so the RTV trick was quick and dirty.

Sal

[JSeery]

Might keep in mind that the flathead is made up of two seperate cooling systems in the engine, right side & left side. A temperature probe located on the engine or radiator hose will control the fan based on only that side of the cooling system. Shouldn't be a problem in most cases, but something to keep in mind.

[V8COOPMAN]

Originally Posted by JSeery

Might keep in mind that the flathead is made up of two seperate cooling systems in the engine, right side & left side. A temperature probe located on the engine or radiator hose will control the fan based on only that side of the cooling system. Shouldn't be a problem in most cases, but something to keep in mind.

In view of what J says above, keep in mind that MOST guys will tell ya that the RIGHT side seems to run a smidge warmer than the LEFT side in most flattys. DD

[AnthonyG]

Sponsored Links (Register now to hide all advertisements)

Thx guys, did a internet search and found Spal the mfgr. Of the fan has another thermal switch assy. With 3/8" npt fitting for the heads. Also thx J & DD on one side running hotter. I have chececked that and on my 8BA it's the passenger side which is the side I had it in the upper radiator hose. I'll make sure I do the same side head with the 3/8" fitting sensor.
Thx all.

[AnthonyG]

FYI here's the Spal 3/8" npt thermal switch on Amazon https://www.amazon.com/gp/aw/d/B018E...ng+Harness+Kit

[40cpe]

Cooling Components has a thermal switch that screws into the head. It controls the fan through a relay. It turns on at 195 and off at 180. I'm running 180 thermostats and it is perfectly coordinated for my needs. At idle, the fan turns on right on 195, runs 2-3 minutes, and turns off. I'm very impressed with the Cooling Components fan for quietness and efficiency.

[40cpe]

Originally Posted by AnthonyG

FYI here's the Spal 3/8" npt thermal switch on Amazon https://www.amazon.com/gp/aw/d/B018E...ng+Harness+Kit

Judging by the model number, that switch appears to turn on at 185. There is usually a 15 degree differential in them. That could keep the fan running most of the time. Here is a link to a selection of probe switches
http://coolingcomponentsinc.us.com/p...erature-probe/

They also have the wiring harneses.

[mrtexas]

Better to control fan with water temperature. I installed a Dakota Digital dash in my 49 hot rod and it has fan control built in. Prior to that the air temp thermostat worked poorly and couldn't be adjusted too good.

[PeterC]

Originally Posted by V8COOPMAN

In view of what J says above, keep in mind that MOST guys will tell ya that the RIGHT side seems to run a smidge warmer than the LEFT side in most flattys. DD

Yup- mine runs approx 5 degrees warmer on the passenger side👍

[AnthonyG]

Think the Cooling components sensor will work with Spal fan?

[V8COOPMAN]

Don't see why not. They look to be a single pole switch straight to GROUND. DD

[40cpe]

Originally Posted by AnthonyG

Think the Cooling components sensor will work with Spal fan?

All the switch does is trigger a relay to send power to the fan. A Spal or Cooling Component will work exactly the same.

[AnthonyG]

Thx guys, as always Ford Barner's are the best!!

[40cpe]

speedway has two different thermo switch temps. from Spal
http://www.speedwaymotors.com/SPAL-T...-Kit,5350.html

[Ken/Alabama]

Mine has a thermo couple screwed into a tap in the bottom of the radiator wired to a relay. Been working for 20 years with no problems.