BIS sump plug thread stripped

[petal]

When I removed the sump plug I found it had been glued in place, and it was soon clear that this was because the thread has been stripped by some gorilla in the past.

The plug's measurements are exterior diameter=22m, thread pitch 1.5mm.  This looks like metric 22mm (M22 fine, or very fine depending on whose terminology you use).  

My plan is to phone around to find a garage who can die-cut and fit a helicoil. Doing this myself sounds a bit scary.  I considered getting a self-tapping tapered plug, but that sounded ugly.  I don't want to glue it again.

How to I unambiguously specify the thread?
Is a helicoil a good plan?
Are ther other options?

Thanks,
Bill (Bristol)

[Chris Lakin]

hi bill, exactly the same prop ive got on my bis sump, they used cheap metal unlike the aircooledmodels which had a smaller stronger bolt and thread.Im planning to get a garage to heli coil mine, best option really, i used araldite to stop my bolt from falling out  :: untill i got fed up and wipped engine out to put new gear box in too.

regards

Chris

[PaulB]

There's a nice little Cornish site on threaded inserts made easy:

http://www.austin7.org/thread_inserts.htm

A torque wrench is a good investment with alloy heads and crankcases - it will pay for itself in no time as threading is a problem.

EDITED!