Jim, I did not hit anything on my 428 cfm port except the pushrod hole, and only about a third of it is showing. So it will require an offset rocker although not much, I'd say maybe .150 offset. So with the port I have right now, a .180 offset lifter would allow the push rod to pretty much be straight up and down. I have not poured my port yet to see how big it is, but an educated guess would be around 300 cc's with the extra flange area. If it did not have the extra material on the flange I would guess around 270 cc's. I did not go crazy big anywhere for this port version on purpose trying not to blow through the roof. I could see from looking at the port that the spring pocket was very close and would pose a problem. I don't see any problem though with getting somewhere around 450 cfm by just widening my port a little more and raising the port entry just a little. I think that I will still be in the safe zone and not blow through anywhere. I just need to get a little time to play some more with it. Never enough hours in a day LOL!!
I did check my valve angle and it is 12.5 + or _ a degree.
Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger Heads and the NEW DCI Ram Air V heads!!!!
|