Air will move faster on the long side of a wing so make a rounded front & a knife edge away from the flow using the long side to direct air past the valve at a 70* angle towards the plug , same will work in the exhaust port cut around the guide creating a wing shape with the exhasut port pointed up use the 7 oclock position as the high point & bring the air around the valve guide , raise the roof 3/16 or so , widen the port so the straight side is flat , this is the common wall in the center ports & the end walls on the outer ports & you can gain 20%+ flow , leave the floor alone . in the intake port & square the port so it is full width from center to the top but leave the pushrod wall there as it creates a venturi & speeds air flow behind the valve , I use a 3/8" round nose cutter with square sides to thin around the guide , you can gain 14% on the intake side . Blend behind the seat you can throat cut to 75* & blend to that , I install hard seats on the exhaust side for the unleaded fuel so you will have a 90* behind the 45*seat .
I hope this helps . there was pictures on this site somewhere that I posted years back you may be able t find them
Topic: Looking for a HP increase for my 440 advice please ( heads cam) (Read 5623 times)
