D_Hall wrote:jonnyboy wrote:Don't tap into an endcap use two pieces of chamber pipe to get to a suitable length then connect them with a tee fitting which reduces down to spark plug threads. Much easier and gives ideal spark placement.
Spark plugs don't use NPT.
Sorry I was under the impression that dyi's 20x cannon used an actual spark plug. Making your own spark gap encased in .5 inch pipe that screws into the tee is always an option.