Quote Originally Posted by louisvanhovell View Post
That's great Andrew, thank you.
Great info. Very technical, yes. But with the tp measurements at hand, it shouldn't be too difficult to make a brass insert (is that the word?) to fit the tp, and then drill a 2.8 or 3 mm hole in it. Degrease the tp, some red Loctite on the insert, and then a long rod to place it in the tp. Luckily I know someone who is good with metal work haha.
Would be a lot easier than tapping the tp.

It is quite a fine operation, to ensure no jagged bits intrude and there is no overlap into the tap area. The TP diameter also seems to depend upon whether or not you use a leather washer, in which case the tp would be rather larger that with a synthetic washer. The links previously mentioned cast quite an amount of light on the optimum size for the tp, especially for the Mk3. I suppose, if you make a narrower tp, then you can then always widen it whereas the reverse is not so simple.

It will be very interesting to know how you get on.

A