Optimal Location for Mechanical Water Temp Gauge Capillary/Bulb on R16

[SP3]

Planning on installing a Auto Meter mechanical Water temp gauge. The original idea was to install the bulb in the head where the present electric sender goes but in looking at the size of the bulb, I don't think that will be possible (haven't been at engine to pull sender and access but the length of bulb looks doubtful).

Where is the next best place to mount the fitting to get meaningful readings to inform of an overheat/head warpage condition - or provide enough early warning to shut down motor?

I prefer not to drill and tap radiator or the cylinder head. My understanding is it's best to measure below the thermostat level.

R16 motor, low windshield car
standard radiator and shroud
4 - blade fan

[sunbeam590]

I installed one many yrs ago, as I prefer to be able to see that the Thermostat is opening and closing as it should and the original electric one
would not allow this, I installed the Bulb in original spot, find one that the bulb is right size ! Gauge mounted Left side of Column below dash,close to centre consul, RH Drive ..
I still run orig Radiator etc, Had tanks removed and tubes Rodded out..Cheers

[SP3]

Thanks for reply @Sunbeam590.

I am leaning towards installing the fitting in the lower radiator hose for now. Easily reversible via replacing the hose if I want to go to a more appropriate location.

Still not completely sure if the top hose or bottom hose gives the more informative temp input - which is pre-radiator cooling and which is post of heat exchange?

On that note what is the high temperature where one should be looking for a place to pull over and let motor cool down. We have a lot of traffic here - and in Summer can get stuck. To mitigate head damage what is the “code red” temp to be vigilant of?

[Curtis]

I installed a mechanical in the stock location. The adapter ended up too close to the exhaust manifold and gave high readings making me think I had an overheating problem which I chased for some time. Aluminum radiator did nothing to change the reading. Put in the stock one and moved the mechanical to upper hose. No more high temp reading.

Got rid of the mechanical after that. I have since added a pusher fan to the front for stuck in traffic driving. Has a temp sensor in the radiator fins and a manual override switch.

[23yrRebuild]

Hi Curtis,
What location, in the radiator fins, did you choose to install your temp sensor ?
Thanks,
Mike

[Curtis]

About halfway down on the right side. Not sure if that's best but that's where I stuffed it.

[23yrRebuild]

Thanks for your info, Curtis !
Mike

[rwmann]

Mechanical temperature gauge Bourdon tube sensor installed in the water pump balance tube outtake (I don’t run the balance tube), with puller fan thermostatic relay Bourdon tube 180 on/ 160 off sensor in radiator top tank.