TC cylinder head plugs

[HCA]

Just came across this old photo ( it came up in a reference on another post) I have of a scanned head section that actually shows the plug. Thread in head does look parallel !

Full scale head section 1 resized.jpg

cheers
Rohan

You certainly have it all at your fingertips Rohan!
thanks. I tried again this morning andwill resort to a re-tap. What ever is left in there is well and truly metallurgically joined to the casting if that is indeed possible

[HCA]

Back on this one again (I have taken a few weeks off the Elan to enjoy the late summer weather in the Evora! )

I did get the old plug out, but many of the old threads suffered, so it is a head off job and weld a new boss onto it.

Before I take this action, is there anything peculiar about the head that a good welder cannot weld on a new ally thread boss..?