Does anyone know what the thread / size is for a water temp sender unit in a mini head?

I'm fitting a speco elec water temp and need to buy an adapter. Their parts cat. has these listed - will one of these work?

adaptor 543-31
1/8 NPT x 1/8” BSP elec water temp
adaptor 543-32
1/8 NPT x 3/8” NPT elec water temp
adaptor 543-33
1/8 NPT x 1/2” NPT elec water temp
adaptor 543-34
1/8 NPT x 5/8” UNF elec water temp

The elec oil pressure sender screwed straight into the block - I was suprised, and happy about that one!

Cheers, Tom.

This was asked last year and came up on a search straight away, althought the stuff you have pasted in looks more like the oil pressure adaptor thread:

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

This is the whole list:

I think both senders are the same thread - the oil came with an adapter, and the water temp sender screws into it, but the adapater is also too small (external).

I've got electric water and oil. So the internal is 1/8 and the external is either 3/8NPT, 1/2NPT or 5/8UNF if any of their adapters work.

They're a common gauge, so if anyone knows 100%, would be greatly appreciated.

This is their complete adapter list:

adaptor 543-31
1/8 NPT x 1/8” BSP elec water temp
adaptor 543-32
1/8 NPT x 3/8” NPT elec water temp
adaptor 543-33
1/8 NPT x 1/2” NPT elec water temp
adaptor 543-34
1/8 NPT x 5/8” UNF elec water temp
adaptor 542-21
1/8 NPT x M14-1.5 elec oil gauge
adaptor 542-22
1/8 NPT x M16-1.5 elec oil gauge
adaptor 542-23
1/8 NPT x M18-1.5 elec oil gauge
adaptor 542-24
1/8 NPT x M12-1.5 elec oil gauge
adaptor 542-25
1/8 NPT x 1/4 NPT elec oil gauge
adaptor 544-41
5/8 UNF x M16-1.5 mech water temp
adaptor 544-42
5/8 UNF x M18-1.5 mech water temp
adaptor 544-43
5/8 UNF x 1/2” NPT Holden
adaptor 6/V8 & SB Chev 544-44
5/8 UNF x 3/8” NPT Ford & Chrysler V8
adaptor 544-45
5/8 UNF x 5/8 UNF fitted with O ring seal

Here it is again:

_________________
SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Can't you use the original one they came with the engine.


Steve

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Classic Not Plastic

Sorry Mick, don't know much about threads - just worked out, is the 16 / 18 the number of threads / rounds per 10mm or something etc - I was thinking it was diameter at first.

I'll look into the 1/8 NPT x 5/8” UNF elec water temp
adaptor 542-21 and see what happens. Was simply trying to get a 100% answer on the size / thread before purchase.

As I said, they're a common gauge and I think some mini people would of fitted them. Don't like the idea of tapping threads in heads if I don't have too. I have an external pipe threader, might have to mod / make an adapter then.

steve1965 - haven't checked - I guess they work on resistance to temp ratio. Will stick them on the stove and meter / compare at alt temps if I have to.

5/8 -18 UNF is 18 threads per inch.
Trust me these fit, you will not buy a 5/8-16 one- 5/8-16 is an orphan thread.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Cheers Doc, now armed with enough info to chase one down on Monday.