Need thread diameter/pitch of heater union pipe

[ryushi5]

I recently took my head to a machinist to get resurfaced. In the process he stripped the threads out of the head where the heater union threads in.

I've already straightened things out with the machinist and am not looking for solutions, I simply need the diameter and pitch to re-tap and heli-coil.

Thanks alot for your help.

 

[Altezza576]

How about you take the union itself to the machinist and have him measure it? most machinists have the correct gauges to measure thread pitch and diameter.

 

[gofastgeorge]

The thread size is 22 x 1.5, but Helicoil does not make an insert in that diameter.
My cataloge only shows 20mm, and 24mm, in much larger thread pitch.

Don't know how your going to save that one.........

 

[Txsupra]

Awhile back I searched and searched for a different fitting to replace my old and busted fitting. Couldn't find one. You'll probably end up having to weld something on there. Carefully.