mk1-forum.net

Ik, so we've sort of established that the crank tap is 5/8-16. I hope so, I've got one and use it all the time.

But... is the hole on the head the same?

I know this is an oil temp gauge, but I guess the sonsor would fit?

http://www.ebay.co.uk/itm/Mini-Smiths-O ... 1e8af06e06

5/8 UNF.

The reason for asking is that I've welded a bung on a Mini sump to measure the oil temp. Which tap should I use?

The thread in the cylinder head for the temp sender is 5/8 UNF.

As above the temperature sending unit hole is tapped 5/8-18 (UNF).

Also be aware that the sender does not seal on its threads but on the tapered seat at the bottom of the hole which mates with the tapered body on the sender (electric or mechanical). Some of the mechanical sending units are too long to fully seat against the taper as their tip hits the inside of the cylinder head casting. For those instances you need the gauge adapter which spaces the mechanical gauge's expansion bulb further from the head. (Mini Spares part TE5).