It dun broked......

[Harry]

Originally Posted by DolSVT00

Problem I've been chasing for years.

On the first build it was my DD so I use my old set of heads that were on my stock engine I blew up on the track, they were Windsor PI heads with 4 threads in the spark plug hole with around 100 plug changes and 80,000 miles. I had them ported, put some good be-hive springs valves and retainers in them and stuck them on.
Eventually over time one by one I stripped or shot the threads out of the plug boss and had to put some inserts in. Inserts reduce the thickness of the boss and even if there aluminum inserts (which I had) as the plug gets hot from racing or making high speed runs (what I was doing when this happened) the heat eventually melted it, once it melted and exposed the threads of the spark plug it was like a torch cutting away at the boss and the valve and eventually messed up the seat and blew out the valve seal letting oil into the CC. (what made me pull it was smoke)

I'd blame it on the tuner.

[DolSVT00]

Originally Posted by Harry

I'd blame it on the tuner.

Him and the builder, and the mechanic that put the insert in...... I believe that one was about 1/16 deeper then the others causing the plug to be lower and expose sharp edges in the CC.