To be blunt, other than the valve job, the Procomp head has enough fairly "ugly" things about it that I skipped even bothering to do a "before" flow test and grabbed the Makita. However, after having some questions re: the results, I picked the best looking (minimal casting flash, best short turn, etc.) of the clone's remaining three unported intake runners and picked the #3/6 for an �out-of-the-box plus a good valve job� test. That's shown in column A. This is the best I can do at this point to provide a �before� test.
Column B is the results from the first round of what I referred to as �basic prep� on #5/4 based on what looked to need work. This consisted of trimming down some big �humps� in the as-cast walls, cleaning up (but not reprofiling) the SSR, blending the valve job into the bowl, narrowing the guide, working the transition from the seat insert into the SSR, blending the CNC'd port opening, and touching up the chamber where the valve job had a stepped transition into it.
Column C is the results from doing some additional work to #5/4, such as widening the short turn, opening the wall near the plug more, and opening the bowl deeper on the exhaust-side of the port. Also, until now everything was primarily a cuttered finish, but I hit the reworked SSR w/ a 60-grit flapper and cleaned up the bowl w/ a 60-grit roll. No actual runner enlargement over the original design size was ever done.
Column D is the improvement between A and C, FWIW.
Lift ------ A ----- B ------ C ----- D
.050 --- 33.8 --- 31.6 --- 32.0 --- (1.8 )
.100 --- 67.6 --- 65.9 --- 66.7 --- (.9)
.200 -- 136.7-- 139.7 -- 141.6 --- 4.9
.300 -- 192.6 -- 202.4 -- 206.6 -- 14.0
.400 -- 245.2 -- 259.5 -- 264.3 -- 19.1
.450 -- 265.8 -- 281.8 -- 287.1 -- 21.3
.500 -- 287.1 -- 302.2 -- 303.9 -- 16.8
.550 -- 293.8 -- 317.0 -- 318.7 -- 24.9
.600 -- 304.5 -- 325.8 -- 325.8 -- 21.3
.650 -- 313.4 -- 333.1 -- 331.2 -- 17.8
.700 -- 315.2 -- 338.8 -- 337.0 -- 21.8
Something in the latest changes have begun to trade off .300-.500" improvements for small decreases above .600".