Re: 359 Spark Plug Threads Stripped

Posted by Owen_Dyneto On 2015/6/10 14:32:35

Cracks thru spark plug holes in the aluminum 359 head are not at all uncommon and the "sleeve" you found was a prior insert repair. I doubt you'll find an oversized thread repair insert so I'm thinking that welding the aluminum in the hole and redrilling and tapping for 14mm is really the best option. I think the length of the threaded section of an 18mm plug precludes that idea.