Understanding results

[What]

If you are not concerned with actual cfm and say that the head started at 'x' on the inclined, can you make that 100% and whatever it reads better from there can be stated as a percentage increase?

i.e.

At .176 valve lift the inclined manometer reads on my scale say a 3.0 at 32inch h20. Some modifications later at .176 valve lift, inclined now reads an amazing 6.0 at same depression. Am I right in thinking that in order to be a 100% increase it would have to measure 12.0... so at 6.0 it would be a 50% increase? Or can you even say that and I'm truly over-simplifying or simply having a brain fart this early in the morning?

On this particular head there was 1.5mm built up around each of the 4 valves (sunken valves basically). This just being some serious shrouding by factory at low lifts. By the time you're done in the chamber, you remove 5cc out of a fairly small head, so it's pretty severe. It was almost likean afterthought they added this material in the chamber just to increase compression... (JDM market 11:1, NA market 10:1... with all this crap removed it would be closer to 9:1)... no other good reason that I see anyway.

Anyway back to topic, closer to peak valve lift % improvements are more in the neighbourhood of 10-15% using above method. It's just the increase at low lifts makes me question using such a method.

[Shawn]

What you are doing is figuring the percentage of change on your scale,not in cfm. For example, let say that at 3.0 your actual cfm is,oh, 60cfm@32"h20, but at 6.0 it is 75cfm@32"h20. Even though you doubled what your scale says, you didn't increase flow in the head by double.
Shawn