Bowl sizing questions

[SpeierRacingHeads]

Big bowl.

[PRH]

Chad, how much bigger are those finished bowls than “as cast”?

[SpeierRacingHeads]

Chad, how much bigger are those finished bowls than “as cast”?

Not sure exactly. The top and bottom were a porters type core. The middle is a 13º ProFiler. That bowl is 105% of a 2.200.

[SpeierRacingHeads]

gives you a better idea.

[BradH]

Just now tried a shot of the ported Victor from the same angle as the Chapman, but not sure it shows well. If it displays sideways, try right clicking on image and open in a new tab.

I'll take pics of where I'm how & measuring bowls.

[BradH]

Crappy pics of how I measure the bowl diameters.

Approx 1.5" below valve seat / top of guide...

[BradH]

Max bowl diameter...

[PRH]

Okay...... got it.

So, after taking .300” out of it...... it’s the same as an ootb EZ head.
And it uses a .010” bigger valve.

[BradH]

Okay...... got it.

So, after taking .300” out of it...... it’s the same as an ootb EZ head.
And it uses a .010” bigger valve.

Looks like it.

What do you typically do for EZ bowls size?

[PRH]

“Usually”, if someone wants fully ported Indy heads, I just sell them the CNC ones.

When porting by hand, I don’t go as big as the cnc program does....... and blowing the bowl out on them doesn’t seem to do much for the flow........ so they don’t get much bigger than they are.
2.100-2.120 ish is what I shoot for on “ported” heads(as opposed to bowl blended heads).

I realize this thread has taken a detour on what I believe the original gist of your question was...... which was how do you decide on what percentage of valve size do you make the bowl diameter?

Much(almost all) of my porting is determined by time/$$.
How much can you do for xxx dollars?

Making big changes in the bowl diameter can take up quite a bit of time, and often does little for me in terms of flow gains.
So for me....... when I start to see rapidly diminishing returns on the bench....... the bowl size increases are over.

In the case of your heads, there was enough core shift, and the bowls were so small to start with....... I brought them up to a size that I thought was still safe, but wouldn’t be holding them back too much.

[BradH]

I hear ya, and that all makes sense.

The good(?) news is the newer castings don't have the same core shift issue, and this job will be for myself. I can charge the customer whatever I want and he'll still pay the bill.

So... given what's been covered above, I am still interested in any input re my original questions.

[PRH]

Without sonic testing there isn’t going to be an answer as to how big your heads can go before they’re “liquid cooled”, but since they’re .250-.300 smaller to start with than they should be....... I don’t think they’d safely go as big as the MW version.

The CNC’d MW version I had here had the bowls at 2.23..... which is nearly 1/2” bigger than your heads started out at.

Is it reasonable to assume you could take out .250 worth of material on both sides of the bowl and still leave enough to be reliable?
These are not “pro-port” type castings.

I know Hughes claims the SM head will sometimes break through in the bowl area when they run that program through them.

My shoot from the hip answer for these heads is...... the bowl size can probably be as big as you dare to take it.

[BradH]

As much as it could be helpful to have a 3rd current gen "crash test dummy" Victor casting to know what the limits are before effing up the "real" heads, I expect taking a conservative approach will make more $en$e.

I don't trust the Procomp / Speedmaster clone to be cast that closely to the original Edelbrock, either.

[SpeierRacingHeads]

Is the Brodix STS B1 BS anywhere close to what your working on? Getting ready to do a master for a engine builder.

[BradH]

Not sure how to make a comparison between a B1-BS and standard-port Victor:
- same OOB 2.20 x 1.81 valve sizes; don't know how much difference in OAL
- Victor intake more raised & extended

20190915_174407.jpg

- both require additional-offset intake rockers, but Victor is .600+" vs .450+"-ish
- B1-BS exhaust port more raised, IIRC
- B1-BS requires different headers, or modifications to "standard" headers that fit Victor & Indy, due to unique spark plug location / orientation

Are you being contracted by the engine builder to create a better standard-port head, or another (close to?) bolt-on Max Wedge head? Odd that they picked the B1-BS, considering it's become the red-headed stepchild of aftermarket BB Mopar heads.

EDIT: I should mention that I don't subscribe to the "Put a Max Wedge port on everything", since my personal builds are all right around 450 c.i. If I was working with another 50+ cubes, it would be a different thing.