The temperature unit being at the rear of the cylinder head will read at a lower temperature than whatever the thermostat is rated at due to the coolant at that point not yet being heated to full temperature by lieu of not yet traveling through the head.  If the sending unit is placed at the front of the engine behind the thermostat, then it will read a higher temperature with no other changes.  In your case, the temperature reading still sounds cooler than normal.

 

The rise in temperature after shutting off an engine is referred to as “heat soak”.  This is where the residual heat within an engine goes into a non-circulating cooling system and simply raises the temperature beyond the point where it was when the engine was shut down.  The five to ten minutes after killing an engine is a good time to be looking for cooling system leaks as there is an increase in cooling system pressure as well as temperature.

Lorena, Texas (South of Waco)

It is normal for the engine to get hotter immediately after shutoff. Are you using the stock gauge? If not using a stock gauge with a stock sending unit they may not be compatible, hence the poor reading. Ford gauges are notorious for being incorrect, but can be adjusted - but I don't know how. Hopefully some one here can help on this.





54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Got a similar question. I am using my original sending location on my 272 with a mechanical guage.  Any reason why it is not register correctly?  I have had the truck running and loosened the plug and coolant comes so I assume it is intalled fine and is surronded in coolant.  I have also driven the truck 25 miles at 60 and it only registers about 110 but after shutting the truck off for 5 min the guage goes up and reads about 130-140.  I also used a infared gun and the coolant in the radiator was reading 150 after the 25 miles.  Any suggestion??  Thanks  

Warsaw, IN

If you’re not running the heater with its accompanying heater hoses, then a temperature sending unit can be put in the already existing 3/8” NPT hole behind the thermostat.  Like Tom says, the other option is to drill and tap another hole in the intake manifold somewhere behind the thermostat.  You'll want to check out the casting thicknesses in that area to insure you've got enough threads for sealing though.

Lorena, Texas (South of Waco)

Danny,



If you install a sender bung in the Rt. side freeze hole, you may also have the option of using the '57-up 12V type gauge/sender combo (no voltage reducer?), if you obtain that adapter size. Since sender bung is usually pressed in, installing with head on the car could be tricky though.

Some install a sender where the water pump plug is, but that only reads coolest temp (direct from the radiator).






6 VOLTS/POS. GRD. NW INDIANA

Danny:

If you are using a voltage reducer for the gauge, you should use the original sender.

John in Selma, IN

John - "The Hoosier Hurricane"

2 questions?

1. can an aftermarket 12 volt temperature sender be used with an original 6 volt gauge powered through a vr-1 volage reducer?

2. are there any locations on the 272 where a second temperature sender can be installed without drilling?

Thanks in advance!

Danny