Fitting Separate Fuel Gauge

[111Robin]

My Mini 30 has the standard three instrument (1275 GT style) pod with the tiny fuel and temperature gauges. I have a separate mechanical 52mm temperature gauge fitted and also want to fit a separate 52mm fuel gauge. What do I need to do with regards the voltage stabiliser ?. As far as I know on the three pod setup the stabiliser is an integral part of the PCB, not a separate unit as on the older cars. Do I just need a 10V stabiliser from an older car to connect to the gauge or is it more complicated than that ?. Would any Smiths gauge be suitable ?, eg. from an MGB or similar ?
Robin

[dklawson]

You are correct, the easiest fix would be to install a traditional, external voltage stabilizer to power the 52mm fuel gauge. You can buy NOS Smiths stabilizer units or search eBay or MOSS for a modern, solid state stabilizer.

You are also correct that most later Smiths gauges (MGB, etc. ) will be suitable for use with your sending unit. You want the gauge with the broader needle that does not "flop around". The early gauges had the skinny needles that were fast acting and can bounce around. They are not compatible with the later fuel sending unit as will be on your car.

The one word of caution I will give you is do NOT expect to operate both your standard gauge and the external gauge from one sending unit. You must choose one or the other gauge for connection to the tank.

[111Robin]

Thanks Doug,
Any idea if there's a likely calibration issue with the tank sender unit versus a new gauge ?. I see a lot of gauge suppliers also state that a matched sender unit is required. I don't particularly want to change the sender if I can avoid it,
Robin

[Spider]

If you fit a Smiths Gauge, you shouldn't have an issue.

[111Robin]

Great, thanks.

[dklawson]

As Spider said, if you have a later (bayonet ring mount) Smiths sending unit and a later Smiths fuel gauge you should be fine. The nominal range of the sending units for most BMC/BL cars after the mid-1960s was about 270 Ohms = Empty to about 30 Ohms = Full. Again, those are nominal values and the actual values of your sending unit will measure a little different.

There is an aftermarket fuel gauge calibration which is close, about 240 Ohms = Empty to about 33 Ohms = Full. You can use those sending units with Smiths gauges as the gauge will read empty before you are out of fuel. I would NOT use a generic, aftermarket fuel gauge with the Smiths sending unit as that gauge will read Empty "late", meaning you might run out of gas before the gauge shows empty.

All bets are off for temperature gauges. Calibrations for those are all over the map.

[111Robin]

Thanks Doug,
I'm running a capillary temperature gauge anyway so no issues there,
Robin