Electric Fan Thermostat Location

I have a 240 and I upgraded to an electric puller fan and removed the mechanical. The engine seems a bit smoother now with the change. I temporarily hooked up a switch to the fan while I sort out getting the thermostat installed. Issue is I need a good place to put the thermostat for the fan controller.

The unit has a 3/8" NPT thread and will fit where my temp sending unit is in the head, but I don't want to lose my temp gauge. I am not using my transmission cooler portion of the radiator, but the unit is too big to fit in there. Any ideas?

I've got a thermostat housing with an NPT threaded hole (and I've seen some without). I've got a mechanical gauge sensor screwed in there now. I forget what the thread size is although I do remember it was a hassle finding an adapter for the sensor I had.

Or maybe work it into where the coolant exits toward the heater core??

Let me know if you want a photo of the current setup on my 200.

on my tractor I cut the raditor hose and made a piece with a threaded connection so the tip of the sensor was in the flow of the coolent (coupler welded to a piece of exhaust pipe)

or google "temperature gauge radiator hose connection" allot out there like this reasonable http://www.glowshiftdirect.com/water-hose-adapters.aspx

Brian could you simply put a "T" at the head and run one of each of your sensors off that??

I couldn't find a thermostat housing with an adapter Fitting, not sure if I am comfortable with making one. I thought about a tee at the head but I am concerned with clearance as well as accuracy since the sensors will not be in direct flow of coolant.

I did stumble upon this:
http://www.proracestore.com/index.ph...ducts_id=10679

I also just found a thermostat housing that will fit and a derale thermatic switch that is 1/8" NPT to fit in it. So many options suddenly appearing:


http://broncograveyard.com/bronco/i-...Fal-QgodSWEA1Q

http://www.summitracing.com/parts/der-16730/overview/

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Originally Posted by olgraybeard

or google "temperature gauge radiator hose connection" allot out there like this reasonable http://www.glowshiftdirect.com/water-hose-adapters.aspx

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Those are nice connections, way better than the ones I found. I think I am going to go with the different thermostat housing. The minimalist in me likes less connections to deal with and having it integrated seems the way to go.

Over the weekend I temporarily put the fan controller switch in the head. I ran it for over 20 minutes and it ran as cool as it ever has. I have a rad cap with a thermometer as well as an IR thermometer. Neither of them read over 185. Once I get the brakes bled I'll take it out and see how it does under load. You certainly know it when the fan kicks on, what a draw :WHATTHE:.

Next I'll need to bribe Pat to help me fine tune this Holley 390. I got a jet and spring kit from Jegs for it. Also hoping to pull a milder vacuum advance from the yard this weekend (in the 10-12˚ range).

Fan temp controllers usually want to read "radiator water temp" to work correctly. Some mechanical sensors (on aftermarket fans) use a capillary line they run between the hose and the lower hose with a special rubber piece that gets clamped along with the hose. Yours is probably electric and not mechanical, so the sender has a terminal, so you may need to take the radiator to a shop and have a bung installed. Would probably be pretty cheap. You can try low on the block too. Maybe a drain on the block is 3/8" NPT?

FWIW I have a temp sender in the Ranchero I can't use because it has 3/8 pipe thread and there is no 3/8" fitting anywhere on a 200 ci block.

It is definitely an electric thermal switch. My radiator is small (19"wide, 23" tall) so not many spots for a bung to be put in. I would think the water outlet would be a good alternative.

Here is a shot of the drain plug for the motor (from another site), looks like 1/8" to me:

http://i627.photobucket.com/albums/t...SCDCP_3001.jpg

Probably the same size as mine on my 200's -- 1/4NPT.

The problem with up high (water outlet) or upper tank on radiator is that these areas trap air and you get steam there instead of water - and steam can be a lot hotter. You need it to be fully submerged and in an area not prone to wild temperature fluctuations - which at the thermostat housing the temps will vary based upon when the thermostat is open or closed. Plus at the water outlet the water is prone to cavitation as the water emerges from the thermostat. Just not a good spot.

Where these water outlet bungs were used (by the factory) was to sense when hot water was present on that side of the thermostat, but not always what temperature it was. Mostly to activate a smog device.