Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Duratec spark plug - hmm

In theory you should be able fit a helicoil with the head on but you will need to consider the access to the job to ensure the old threads are drilled out properly, the oversize tap is started correctly etc.

Also, the taps in helicoil sets tend to have straight flutes rather than spiral flutes, which will tend to allow the swarf to drop down the bore irrespective of whether the valves are closed.

Have you done a compression test on the affected bore to check for leakage past the damaged threads?


Arwyn