Temp Switch Location for Rad Fan

[MercuryMarc]

I currently have my elect fan temp sensor switch tapped into a "T" fitting on the lower rad hose. I'd like to drill out the thermostat housing and tap a hole to mount the temp switch there.

My thermostat housing has an area that looks like it was designed to be drilled and tapped:

Any suggestions on how to drill and tap the housing?
Thanks!

 

[powerband]

I currently have my elect fan temp sensor switch tapped into a "T" fitting on the lower rad hose. I'd like to drill out the thermostat housing and tap a hole to mount the temp switch there.

My thermostat housing has an area that looks like it was designed to be drilled and tapped:

Any suggestions on how to drill and tap the housing?
Thanks!

I attempted to drill and tap the thermostat casting with a non-NPT tap and didn't have success. The casting cracked when I tried to screw in the NPT thread sensor. I then took a second casting I had to my machinist who had the 1/2" NPT tap. He drilled and tapped it for $ 20.oo
. I'm using a Permacool frameless fan and Permacool adjustable sensor. Fan was @ $110 and sensor/module @ $50.


Thermo housing sensor, control module on left fenderwell.

Powerband

 

[MercuryMarc]

Thanks PB!
I have an extra housing so if it cracks I'll still be able to drive using the other one. I am running a variable temp sensor switch and Derale 14" fan in the pusher position, with a standard 3 row replacement Ford radiator.

 

[powerband]

MercMarc,

I just meant the regular tap I borrowed, worked for tapping a regular US thread in the casting but the NPT (Pipe Thread) fitting with it's tapered threading was the problem. If you can borrow or acess an NPT tap you should have no problem. The casting is soft and taps easily (and cracks easily ).

Powerband 8)

 

[Bort62]

Yeah, make sure you use the right tap.

A 1/4" NPT tap is only like 7 or 8 bucks at the hardware store.

 

[MercuryMarc]

Thanks Ian and PB-

I'll get the proper NPT tap and go for it!

 

[addo]

Remember it's a tapered thread. So you only need to run it far enough to create good threads for the sender's collar length.

That said - some taps are ground with so much lead-in that you might need to tap initially, then grind (slowly, to avoid drawing temper) ¼" or so from the tip, then complete the tapping process.

Regards, Adam.

 

[jahearne]

Derale also has a push-in sensor for the radiator fins.

http://www.derale.com/adjust-fan-controller.html

 

[matt1967]

some of the housings are tapped for 1/8" arleady. I have 2 for '78 250's, and they are tapped for 1/8" and have pipe plugs in them. I'v seen earlier 1's with 1/8" tapped too. outlet size for the 250 is bigger so these 2 are useless to me, even tho I do need 1 ( small holes are rusted right thru where the hose goes on my old 1 )

 

[XFlow_Fairlane]

huh...

all of mine are cast AL.

the early ones I have (c2 c4) are plain and smooth pretty much...polish up nice and easy!)

I know I have at least one late housing with a 1/8 or 1/4 npt hole in it. you might be able to have a bung welded on it too (might be a pain being the alloy is low quality, old, and impregnated with antifreeze)