Coolant tap on TR3 block

[DaveC]

I have now purchased two block taps from Moss Motors, and one from Victoria British and they either don't fit or they leak.

Does anyone know exactly what thread size is needed, as I'm just going to put a blank in the block.

Thanks in advance for help!

dave

[sp53]

If you are into originality, take some black silicone or whatever and plug the hole on the original tape from the back and then if you want to drain the block remove the whole tape.

[DaveC]

Thanks - i think that's what I'll do.

[Sarastro]

I have had more leakage problems with those @%!# valves than with anything else. I gave up, long ago, and just use a plug.

Here's what I did on the TR engine. The washer is soft-soldered to the bolt, so it won't leak, and the black thing is a washer I made out of delrin. You could use any solf material for the washer, probably even unhardened aluminum or a copper washer. The bolt is 1/2 fine threaded; it appears that the thread is not a pipe thread, which I would have expected.