Exhaust stud

Despite preparing the exhaust studs with penetrating oil for a week one of the studs broke off at the nut as I undid it leaving an unremovable piece behind. Luckily I live in Sheffield where in one part of the City - Attercliffe - there are still engineering shops that specialize in machine tools and lathes you have to be 100 years old to understand. 
The guy recommended cutting the remainder of the stud down to the head, then centre punching followed by a 4.9mm drill, followed by two different 6mm taps, the first of which was cut away in a screw shape to remove the swarf from the blind hole. Worked a treat and it can be done with the engine in the frame. I think its really worth going the extra mile to buy quality drills and taps etc. that are precision ground and hard, to use for a critical job in an awkward spot.

Glad you've sorted it.

Thanks a lot Sullivj, I'm sure you've had similar fun with your bike, to get it looking as good as it does

Thanks.

I was talking to a guy with a 1927 Rolls Royce at the weekend. £75k car - beautiful.

He had to replace 4 broken exhaust studs this year. He had to cut down his tap due to the limited access and slowly tap them out and helicoil them - what a pig of a job!

Great to hear that you manage to get this sorted. Always helpful to find someone that knows...

Wow!

That's exactly the nightmare job I fear. Only, once the stud has snapped, it's too late.

In preparation for precisely this kind of job, lady fortune decided I could use a Draper 6mm stud extractor. Hopefully, this means I can avoid the drilling-tapping-helicoiling inferno!

Sending a kind thought to a kind mate...