Spark plug hole crack repair

Aloha, BAE early fuel head has a small crack running down about 4/5 threads (visible) I know of the replaceable threaded inserts for the repair. Is it advisable to tig the crack and then insert, is welding necessary.
Mahalo, Doug

 

No experience with these threads myself, but in general a crack will keep growing since the end of the crack is a very sharp edge thus creating a high stress concentration under load. In some parts they will drill a hole at the end of the crack to keep it from growing which of course is not an option, so I'm guessing that welding the crack (not just the surface) is your best option.
I think there was a post on inserts on the forum in the past. I remember seeing something about not to use steel inserts, but to replace with aluminium only, so there might be something on welding as well.

HTH.

 

you need to weld it up..hello to my family on the north shore
Dave