I did a fair amount of back cut testing on Brads heads.
They didn’t respond well to a long back cut.

Here is a close look at some of the ones I did for Brad way back when.

4 angles, longer top angle, bottom angle blended into bowl, no pronounced edge where the valve job ends and the bowl starts:

It looks to me as though the CNC lines had been polished out of Dave’s heads before they were put into service.

I’ve never seen where bead blasting the heads would make the lines disappear...... so I have to assume they just weren’t there.

The bottom angle thing is probably just how it looks in the other pics I posted.

In this pic the bottom angle does seem like it’s about 60*

A lot of this stuff is hard to really assess without having it in your hands.

BTW, what did the chamber volume end up at after the milling?

Thanks for looking and assessing. The valve job stays as is and heads are going back on soon. Steve took off .045 from deck and .054 from intake side giving me 67cc in the chamber. If I use a .040 gasket that would give me 12.6:1 and with a .045 gasket would give 12.44:1 compression.

I didn’t think you’d be changing that valve job......i’m just passing on some observations.

Is the short block zero deck?

no, its .002 positive. If I keep the heads they will get a JV next time.

There is likely “some” flow to be had by cutting the seats and some blending....... but whether or not that would show up on a time slip is another story.

Maybe I should have a couple ports flowed before I reinstall the heads.

Well...... “flowing” the heads doesn’t actually make them any better....... but at least you’d know what you have.

I looked at my notes again....... when I did my test, it was a 4 angle seat and 2.25 intake valve.
So...... there could still be a 4 angle seat in one hole, but that’s not going to be representative of what the others flow with 3 angles and a smaller valve.

My notes show I tested the number 4 or 5 cylinder.
So if you pull those two intake valves, one of those seats might still have the 4 angles...... although if they recut it, the 4th angle could be mostly gone.

It would be good to just know what I have. I may check that tomorrow.

If you find one seat still has the 4 angles..... what i’m saying is...... flow a different one.

ok, I understand. I will have the one flowed that I just pulled the valves from.

Dave - Can you get any clear close-up pics of the intake valve seat?

FWIW, here's my original Hughes CNC Victor and a Chapman Stage VI. Both pics should be clear enough to zoom in to see more details of their respective valve seat configs.

EDIT: Stupid questions - what size are the intake valves... and are they all same size?

I put the valves back in Brad. I see what pics I have to post.

A few more.

CNC ported ProComp Victor I prepped last year:

If you're brave enough... it wouldn't hurt to run a cutter finish around the bottom to blend the sharp edge.

I think ill leave as is for now.