Radiator fan switch - where?

Jokester · March 31, 2009, 11:44:01 PM

After a many year hiatus, I finally got my coupe running tonight. I now realize that I have no place to put the fan switch. There are 2 coolant holes in the manifold, one for the heater hose and one for the temp gauge. I currently have the fan switch in the thermostat housing. I don't care for it there. I'd rather put it in the block or manifold. There are no holes in the heads. As I see it I have 2 choices; put an ugly tee in where the gauge hooks in, or put a switch low in the block where the petcock drains are. Are either of these choices feasible? I've never seen anyone put a switch in a tee or low on the block. Would it work?? I'm using old (1963) heads, is there enough wall thickness in them to drill and tap a hole like on later heads? Oh, small block Chevy by the way.

thx,

.bjb

enjenjo · March 31, 2009, 11:54:24 PM

You can drill the rear of the manifold where the water crossover is in front, and tap for a sensor there.

Jokester · April 01, 2009, 12:01:51 AM

Don't think so, it's an Offenhauser cross ram. If I remember correctly there's a pretty hefty reinforcing rib right over the water port. I'll double check that tomorrow.

.bjb

rumrumm · April 01, 2009, 08:08:57 AM

It was a little pricey, but I solved the problem by using a spacer which fits between the manifold and the thermostat housing. It has two threaded holes for additional sensors and is available from Summit.

sirstude · April 01, 2009, 09:33:52 AM

Dakota Digital and Speedway both have fan controls that use the temperature gauge sensor to run the fan. You don't have to use 2 senders then.

Doug

Jokester · April 01, 2009, 01:09:34 PM

Sorry, mechanical gauge, no sender. Keep trying.

.bjb

EMSjunkie · April 01, 2009, 06:16:42 PM

Quote from: "Jokester"Sorry, mechanical gauge, no sender. Keep trying.

.bjb

Speedway has 'em for mechanical gauges too.

check it out

http://www.speedwaymotors.com/Electronic-Cooling-Fan-Control,2356.html

I have one on my Coupe, works great.

Vance

enjenjo · April 01, 2009, 07:26:04 PM

Quote from: "EMSjunkie"
Quote from: "Jokester"Sorry, mechanical gauge, no sender. Keep trying.

.bjb

Speedway has 'em for mechanical gauges too.
check it out
http://www.speedwaymotors.com/Electronic-Cooling-Fan-Control,2356.html

I have one on my Coupe, works great.

Vance

With a mechanical gauge, is says it comes with a sender, which would put him back where he is.

enjenjo · April 01, 2009, 07:28:20 PM

Can you use a water pump, with a bypass connection, and use that hole for the sensor?

phat rat · April 01, 2009, 08:08:26 PM

OK I'll add another alternative. Take the radiator to a shop and have a fitting put in the bottom tank for the sensor. That's where I have mine and it works fine. Although I had mine done the easy way. It was done when the radiator was built

34ford · April 01, 2009, 08:51:00 PM

Quote from: "enjenjo"Can you use a water pump, with a bypass connection, and use that hole for the sensor?

Since the subject of location is being discussed I have mine in the hole in the top of the water pump on my sbc. Thought that was a good place to put it then realized it probably was the temp of the water returning to the motor. So I haven't moved it yet as it always runs really cool with the 4 row aluminum radiator.

Is this the location you are callling the bypass connection?

Thought of putting it the side of the head be a good place or would it show it to hot there??

Crosley.In.AZ · April 01, 2009, 10:12:55 PM

I have a sensor type with relay device.

A temp probe sticks into the radiator fins. I adjusted the temp device so the fan kicks on just above the thermostat temp rating.

when i roll to a stop like a traffic light, the cooling fan will kick on if i sit long enough