Temperature sensor relocation in BE with A 1275

[lbcfan]

The 1275 that I've installed has an adapter for a water temperature sensor on the passenger side of the head. I've ordered a plug to replace the adapter, but I'm wondering if it's common to relocate the temperature capillary from the downflow radiator to the engine in such a case.

Several years ago my water pump failed and I never knew- the sensor in the radiator did not indicate a problem when I lost my coolant. I drove until the engine lost power and quit. If the sensor were in the head I assume that the temperature of the engine would have registered on the sensor, and so the gauge.

Of course I've already installed the capillary in the radiator, but I'm running out of things to do...

Any thoughts?

Michael

 

[Trevor Jessie]

I used the one in the head, and used the one in the radiator for the electric fan.

 

[Billm]

It is best to put the temp gauge in the adapter, is is best to use the adapter since if you put the gauge into the head without the adapter you will bend and sometimes break the temp sender.
BillM

 

[TulsaFred]

Thinking of this for my 1275 conversion as well. I tried to plug the radiator while doing some testing but the thread seems nonstandard.
Anyone know the thread in the radiator and/or head temp sending holes? What adapter is needed if the head is used?

 

[lbcfan]

Fred-

I've ordered a plug from Moss Europe. I'll let you know if it fits the radiator, but it looks as though it should. They also sell the adapter for the head.

It's interesting but they often have these small pieces that the US distributors do not. For example, I bought the ready-made driver side front brake line from them.

Michael

 

[Billm]

The threads in the head, radiator and adapter (inside and outside) are all the same (and same as the plug and temp gauge senders).
BillM

 

[BillW103]

The timing mark plug from a Harley Evo motor works.

 

[dklawson]

The threads in the head are 5/8-18. I assume the ones in the radiator would be the same. As mentioned by BillM, you will want the adapter fitting to make sure the bulb on the capillary tubing is not damaged by a shallow port in the head casting.

5/8-18 is close to (but smaller than) 3/8-NPT. If you have a friend with a 5/8-18 die you can re-thread a brass 3/8-NPT plug to turn it into a plug for the temperature sender.

EDIT: Of course... you could always use an old electrical temperature sending unit for a plug in either the head or the radiator.

 

[TulsaFred]

Excellent info, thanks!