Sensors in Fiat TC cylinder head

[Jefftav]

I want to fit an oil pressure guage and water temp guage to my 2L twin cam. The cylinder head has 2 sensors fitted between the spark plugs and I am hoping one is for water temprature and one is for oil pressure but having consulted the manual I have it's a bit vague.

If these are the sensors then I assume that I need electric (not capillary) guages but do these have to be Fiat unit or can I use aftermarket guages (Smiths?).

Thanks in advance.

[Guy Croft]

Originally: One threaded port was used for an overheat sensor which sent the needle of the original 124 gauge into the red zone. The other was for an ordinary coolant temperature sensor to operate the needle of the same gauge in the normal operating range. These senders can be identified by heating them up progressively with a gas lighter or similar and reading the change of resistance between the spade terminal and the brass body.

As far as gauges go there are numerous variants available and you must make sure that you can fit the sender into the head (which is 3/8BSP) or else procure an adaptor. Think Automotive in Isleworth UK make a huge range of adaptors.

When buying gauges always, always read the information about 'sender unit threads'. My preference for gauges is RaceTech from Raceparts UK or VDO - quite readily available fromDemon Tweaks. Most manufacturers seem to be moving away from capillary type gauges towards electric these days.

The above applies to oil system accessories like remote filters, Think Automotive are my pref supplier and they offer pre-threaded accessories to marry to any sender type.

GC

[Jefftav]

Guy many thanks, lots to keep me busy with.

[turbofiat]

Guy many thanks, lots to keep me busy with.

I don't know about your twin cam but on mine the oil pressure switch is on the backside of the oil filter housing. On the opposite side of the housing there is a brass plug. I used this port to feed oil to my turbo and removed the switch and installed an oil pressure sensor for my gauge.