TECH: Intake Valves

I like these valves available from Eastern Motorcycle Parts.  They have nitrite coating which allows you to set-up your valve/guide clearance a bit tighter (especially with cast iron guides).  The valves can be cut and machined to suit your seat size.  Shown below:  I'm using the larger KH Intake Valve, but cutting the head dia. to 1.750 to fit the smaller K Model Intake Seat.

I had the valve head "lip" machined off (uncut valve on the right) to aid in flow between the valve and the head.  Jerry Branch found the best flow with +.120 to +.150 above the intake valves.  The Eastern Part No. 18070-54N(N for Nitrite).  Nitrite coatings are proven to decrease valve "stick" and add to the life of your valve and guide.  Kibblewhite valves are also a good choice. 

After I grind the 45 degree on the valve, I re-adjust our Kwik Way valve grinder to 15 degrees and take that small edge off at the top of the 45 . . . Our engine building friend (I'll just refer as, Radar) told me that little bevel increases port air flow and efficiency "about as good as anything."  Since the air and fuel is coming in - flowing towards the bottom on Intake valves, we don't need that lip messin' up our path.  On Exhaust valves, the 15 is not as critical, but I usually put the 15 on too....I also bevel the outside(top lip) since the air is coming at the top of the valve, to help get that exhaust out of there !

Bottom Valve: The bottom valve just looks better . . . There are few aftermarket products that are ready "right out of the box" . . . but these valves at least may be modified to your liking.  It was easy, everybody would do it.