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Spark plug thread reach

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I'm looking for an alternate plug to BR8EG with shorter thread reach.

Short story,

I had the squish machined to .045 and had material machined from the dome to keep cc's at 23.5. 

The goal on this one was to keep the dome profile the same in order to minimize changes to the powerband. 

After a few sonic thickness readouts, the dome was cut and gauged to match the original profile. The only downside to this was losing some of the sparkplug threads.

The first picture shows the plug seated completely. Second picture shows the thickness required using washers or shorter thread reach plug. Third pic is what the plug should look like with correct reach.

I have found a BR8HS with shorter thread reach but the S series will be a standard core vs the G series. The H plug will be too short without removing the beveled washer.

Is there an alternate "H" for BR8EG or do I use copper washers to get correct depth? 





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