Long story short, I recently picked up a Procomp BB head to use for what I'm referring to as my "crash test dummy" porting R&D head. I tried to locate a single 75 cc Victor like my last set to do the same thing, but Jesse Robinson (RAMM) and I swapped some PMs and he confirmed that I could use a Procomp "clone" for the same purpose.

Before I purchased the head directly from Procomp in SoCal, I contacted Brian (ou812) at IMM about doing a good valve job on the head before I bothered to mess with it. Since his shop is only about an hour's drive from Procomp, I had them ship it directly to IMM, and he sent it to me once the work was done, along w/ a couple of Edelbrock valves as used w/ Victor heads.

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".

Despite having a 2.20" intake valve, the intake opening is only about 2.25" x 1.20" (standard BBM, not Max Wedge) which is more in line with a common small-block Chevy runner opening.

BTW, I have no intention of running Procomp heads and this purchase was strictly to give me a casting I could try and prototype some Edelbrock Victor standard-size ports of my own.

Any backcut on thevalve. Jrob

30*

I've found improvements in the .500 lift range and up by widening the bowl/roof area. You might try blending the bottom cuts one at a time.

The Pro-Comps are identical to the Eddy's in every single aspect with the exception of appearance-right down the water jackets and how much material there is. I tried a CNC machined venturi shape below the seat into the bowl as that has really worked in the past. It did not work all that well on these, I think I missed the angle of attack. There is a ton of material in the bowls-do not be afraid to make them any shape you want. The S.S. is narrow in width and to short-it is critical to get right for low lift numbers to be decent.The valve job has very little impact on these heads for some reason. I have tried every combo of angles and with a 50* seat the numbers don't really change. I will tell you that raising the port and filling the floor does work for these heads--I cannot figure out why they wouldn't cast them this way? Valve position relative to the bore is the biggest problem with Mopar's B engines as we all know. Heavy angle milling on these is your friend. I have taken as much as .300" - 0", this moves valves 2.25 *--it works extremely well. I'm about to get serious with a set and move guides to where they need to be and see what happens. This is all I can share for now. J.Rob

Brad I don't want to tell you what to do as you are doing fine by yourself BUT at this stage if you want to step up your porting program get yourself some method of measuring air-speed. Bruce on the flowbench website has a great tool for both the intakes and exhaust.

Increasing intake width is very important with these. Stock narrow port window cause very abrupt width increase at short side leading to turbulence and stalling at the .650" and up. These things need to go Max Wedge-. All of this still won't fix the poor low/midlift numbers though. J.Rob

"Valve position relative to the bore is the biggest problem with Mopar's B engines as we all know."
Are they positioned to close to the bores edge and not centered enough? What is the valve angle of the BB Mopar? Isn't it 15 degrees?

Brad what's the current throat I.D.?
What does the roof width measure by the guide boss?
What width is the short turn now?

Std. port opening is just too small for serious flow....

Measured the throat (~90% of valve), but don't have #s for all of the other areas you asked about.

Measured the port opening and IIRC it was slightly smaller than I expected... maybe 2.25" x 1.98"? Makes more sense why Hughes went "semi-Max Wedge" at 2.40" x 1.30" with their "standard 440" CNC version, but not a full 2.65" x 1.35" MW.