My intention is to not start, or have, a pissing contest in regard to whos head performs better. I know some of the boys on the left coast are having some success with D-shaped ports on early Triumph heads, while maintaining the integrity of the hemi combustion chamber; but the D-shaped ports are not as radically shaped as are the ports on Jacks head.(would love to see the flow ##s on the head when Jack is finished never the less, we know it (D-shaping the port) works as long as the entire length of the intake tract follows suite. And all I can say is, Jack is a vary ambitious fellow. I don't have the time at this point to get that involved with an XS head, or any other bike. Im building boat motors at this point (BIG 2 Strokes) in any event the commit I made in regard to valves on a conventionally ported XS head is sound logic and proven. If your going to rebuild a head why put it together with parts that are substandard??? If you cant afford the go fast parts that have been proven on and off the track, stick with the best stock parts you can get your hands on; and measure everything; twice.....
Good luck, I'll stop back in next time its too damn cold to do anything else.
Good luck, I'll stop back in next time its too damn cold to do anything else.