Fuel Tank Sender

[k8207418]

I’ve managed to get hold of a tank but can’t find a sender so I’ve fitted a Spright unit
I haven’t managed to find nuts to bolt it on unfortunately 
The OD of the thread is around 0.2 of an inch so I’m guessing 7/32 bsf
If that’s right anyone know where I can get some ?

[Jeff Taylor]

I believe the six machine screws to bolt the sender to the tank are 5/32" BSW thread - the same as old Meccano bolts if you're old enough to remember those, sadly I am !

[Martin Prior]

I've just fitted one quite happily using 3BA

[k8207418]

Many thanks for both responses
I’ve looked at 5/32 and 3 BA and both have .15” ish major diameter 
Studs I have are 0.2” which is a significant difference 
For my information any chance you could measure yours ?
Thanks

[John Cornforth]

Hi

From my rusty memory the early Sprite senders (Moving iron type dashboard gauge) were about 0 to 70 Ohms resistance. The later senders (Thermal type dashboard gauge) were considerably higher in resistance.

The Austin senders were more like 0 to 30 Ohms. So your gauge reading may not be the most accurate in the world, but it's a lot better than nothing !

You might consider rigging up sender and gauge temporarily out of the tank, and moving the float by hand to get an idea of what reading to expect.

[k8207418]

Yep
I have no concerns on calibrating the system
It’s bolting the sender in so I can test the tank I’m concerned with at the moment

[Jeff Taylor]

k8207418,

It sounds to me as if a previous owner has probably drilled and re-tapped the tank sender flange to accept larger diameter machine screws - so they could be any thread. As far as I'm aware the Smiths sender attachment machine screws were in the 1930's universal across all makes of car (not just Austins) that were fitted with their sender units - my 1936 Morris 8 Tourer (which I've owned for almost 50 years) has an original Smiths sender unit similar to that in an Austin 7 complete with the original machine screws of 5/32" BSW.

[k8207418]

Ok
I have ordered some of those to check
They were only pennies so no worries
Many thanks all