sbc electric fan temp sw location Head or Intake

Im installing a few painless fan relay kit PN PPP30103 in 350 sbc with edelbrock rpm performer heads and dual quad intake and would like to know the best location to install the fan temp switch...head or intake? I had been told by a friend it was best to install it in the head which make sense, but the temp switch installed in the head with the 1/2" adapter makes it extend out very close to the header tube and I am afraid would melt the connector and wiring. also, would it make any difference if it was installed in the left head with the switch at the front of the engine or could it be installed on the right head located to the rear of the engine. It would be great if the switch did not require the 1/2" adapter as then it would not be an issue with it being so close to the header tube. I suppose I could insulate the wires with DEI or other hi-temp sleeving, but do not care to have it that visible and it would look ugly. If I was to install it in the intake manifold the only available ports would be at the rear of the head on the right bank, but would this location work for the switch or not? My judgement tells me it is not the best place to install it. Any ideas and help would be appreciated.
Thanks,
Mike M
Kentwood, MI

 

Installing the switch in the head is the best location that is where the heat is transferred to the switch will react slightly quicker as opposed to the intake. I installed one in the back of the intake on the blower car and the switch never seemed to come on until it got to about 220 switched to the head and fans came on at 185 which is what the switch was rated for

 

Remember heat rises and the best place for a fan switch is as close to the thermostat as you can get it. This will give you the most accurate temp opening unless your switch is set at 220.

 

Heat does rise but there will be more heat at the combustion chamber than at the thermostat not necessarily a huge difference but a difference

 

thanks guys, the switch is rated for 175 and agree with blown that at the head there would be more heat, but would it make any difference if it was installed on the right rear side of the head or would it best work on the left front side of the head. I still am fighting with the wiring being so close to the header tube weather it is installed on either head. Maybe I will call Painless tomorrow to see if they have a switch that is 1/2" thread so the adapter to the 3/8" switch is not used.
Mike M

 

No either head location will be fine. I believe they do make a 1/2 npt switch

 

I doubt that it makes a nickel's difference. Put it where it is most convenient (or the most hidden, if that is your priority).

 

Heat radiates in all directions hot AIR rises ...just saying

 

I got an adjustable fan switch from gearhead enterprises and it uses the same switch as your water temp guage really slick and less clutter.I have the adjustable part under the dash.

 

Put it as close to the thermostat as possible. That's the temp that the radiator sees and should be the hottest temp within the engine.

Frank