Head Porting

[SilverXJ]

I wouldn't modify the chamber w/o wet flow testing.

On the indentations, I don't know what they do yet, but it appears that the Hesco head lacks them. This is the best pic I could find of the combustion chamber, even then its hard to tell for asure. I hope they took that assclown in the picture out back and shot him for butchering the head like that.

[George Dickel]

Not to mention his workbench organization...

[Desertjr]

I'm gonna knock them off my head, and open the chambers slightly..on my last head I feel I did a bit too much and wasnt happy. Starting over now with a new 7120. Didn't mess things up..but wasnt happy..could be run but I'd rather have piece of mine I guess lol.

[Flash]

Where are these dimples???
Any one have a pic of it?
Are they in the combustion chamber, port, or are we taking about the intake?

[I6FAN]

IMG_4139%20(Small).JPG

I believe their talking about the indentions circled. I always thought they were something from the casting process for core alignment, or like a casting sprue(?)...but they are on the port-side of the chamber do they serve a purpose to impede flow there to promote it on the far, spark plug side of the chamber during overlap?

[SilverXJ]

They are for the core alignment at the factory for machining processes.

[I6FAN]

They are for the core alignment at the factory for machining processes.

I here you, and I'm inclined to believe that's the purpose also, but playing devil's advocate here, these things do resemble a large golf ball dimple, and we know that would create a turbulence. In a reverse flow cylinder head [non-cross flow head], would you get a "preference" to "hug" the region of the chamber closest to the in-and-out ports leaving the region further away vulnerable to lower flow and poorer "clean-out" like in chamber 1? But, if you added some sort of surface resistance, as in chamber 2, it could help to "push" the flow back to the far side of the reverse flow chamber preventing the dead zones that surly would be there. Just saying...something to ponder there are not many modern reverse flow heads anymore, and if there were, what engineering tricks would be employed?

[darkcorp]

Hi, guys!
I decided to lower my CR from 10.5 to 10.2 by opening combustion chamber. I would be satisfied if my head had 60cc. So where can I remove excess material from head not make it worse? From side walls near the valves to give some space for airflow?

[Russ Pottenger]

You'll pick up 3-4 cc's just by switching over to Chevy LS valves.

If you shoot me over a email to [email protected] I'd be happy to forward you examples of my finished combustion chamber to help show you a example.

Russ

[darkcorp]

Russ Pottenger, thanks for your reply. I have seen pics of your head work. They are a good example for me:



viewtopic.php?t=4823

I have a set of new stock valves and have no wish to change them to Chevy LS valves.
But! I could machine them to tulip form. I guess that will give me 1-2 cc.
If I gain extra 3 cc more from opening combustion chamber it will lower my CR to 10. That seem much more safe.