Morris Minor Owners Club

Hi, I've ordered a oil pressure & water temp gauge, would like to get the adaptors ordered ready, does anyone know the thread size of the oil sender (the one near the back of the block(67 traveller) also the thread size of the blanking plug at the front of the head nr the thermostat housing.
Thanks

Barry,

The tapping in the block for the oil pressure take-off is 1/8" NPT (American pipe thread). If you intend to keep the oil pressure warning light (a VERY good idea!), you will need a 'T-piece' kit, something like this:

https://www.minisport.com/lmaac16-oil-p ... piece.html

Use some PTFE tape on the taper threads for security of leaks.

The water temperature tapping in the head is 5/8" UNF - check this as I have seen this thread stated as 3/8" BSP, but I have only experienced 5/8" UNF. Are you fitting a mechanical or electric gauge? What thread size for the sender are you getting? The standard 'Smiths' electric gauge sender should just screw directly into the head - again a little PTFE tape will do no harm.

It it's a mechanical gauge, you will need an adaptor between the 'bulb' and the head - the thread, male/female, for the bulb will depend on the bulb type.

Hi, Thanks for that, the gauges are electrical & the thread size of the senders is 1/8 NPT, I'll get a T piece for the oil gauge that means its 1/8npt 2 females & a male, re the water gauge, guessing!! by the size of the head of the blanker 5/8 sounds more likely than 3/8's. I'll order one of those too, hardly going to break the bank!
Merci

Barry,

3/8" BSP is 0.656" diameter - it is a pipe thread, so not measured like 'ordinary' threads. If the 5/8" UNF adaptor is sloppy then it could be 3/8" BSP, but I think unlikely.

Although the oil pipe connection in the block is 1/8 NPT - the oil gauge sender may NOT that be that size. Check carefully before wrecking threads. You need the correct T adapter which will allow the original switch to fit in one port - and a suitable thread for the oil gauge sender - whatever that may be - should really tell you with the gauge. Be sure to run the temp gauge from the 10 volt regulated supply on the speedo. Not sure about the oil gauge - it may also need the 10 volt supply, and again it should tell you that with the gauge instructions - surely??

Pretty sure it was a 5/8" UNF adapter I got when I fitted a temp gauge, but cant for the life of me remember where I got it

The 10v supply is for Smiths 'hot wire' gauges - is that what you are getting? What do the instructions for the gauges that you are getting say about the voltage supply?

Thanks so far, I'll know more when the gauges arrive, I was just thinking to get the adaptors so I was ready to go when they did!

Any electrical temp gauges I have seen use the 10 volt supply - otherwise the reading will rise and fall with the battery volts. No sure about the oil gauges - much better anyway with a proper mechanical oil gauge - but again I suspect it will want 10 volts to maintain a steady reading. the question arrises - how much output can the standard 10 volt unit supply when designed only to supply the simple fuel gauge......

Hi everyone, gauges have arrived & thee is no mention of what voltage. Each has 3 terminals + , - , s. Obviously s is sender & - is neg earth, For the pos, is it best to try the 10v first? & where on the speedo gauge would it go?
Thanks