4g67 Head "Porting" Question

[97egl]

I have a 4g67 head that I am working on "porting" for a 6 bolt going into by 91 laser. (I put porting in parentheses because I'm really just cleaning up the casting and not taking much material off) I noticed that there are little humps in the exhaust right next to the short radius in between the bowls and runners in these heads which are not in the 4g63 heads that I have ported. I don't have a scrap 4g67 head to cut in half to see how much material there is. Popping the freeze plug out of the end of the head it looks like there's plenty of material but would like to know for sure before I go grinding a hole thru my exhaust port.

Attached pics of the bump. Hopefully somebody out there has ported one of these before. Thanks Guys

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[EC17PSE]

Seeing is its on the outside and faces in i would assume its not bad bad as its pushing the flowing air in towards the middle of the cylinder cumbustion,

I have never done these heads so cannot hell there so sorry if my thoughts are not of help

 

[97egl]

Seeing is its on the outside and faces in i would assume its not bad bad as its pushing the flowing air in towards the middle of the cylinder cumbustion,

I have never done these heads so cannot hell there so sorry if my thoughts are not of help

I certainly appreciate any input. These being in the exhaust ports only tho I would think would impede flow quite a bit. They made the short radius narrower and the short radius seems to be where a lot of improvements in flow come from but maybe there is a reason they are there. Anymore input on that would be greatly appreciated.

Thanks

 

[EC17PSE]

I certainly appreciate any input. These being in the exhaust ports only tho I would think would impede flow quite a bit. They made the short radius narrower and the short radius seems to be where a lot of improvements in flow come from but maybe there is a reason they are there. Anymore input on that would be greatly appreciated.

Thanks

Arh sorry i thought it was the i take, my bad on assuming.

Exhaust would want to be opened up a bit yes and smooth as possible for flow. I wonder if there is a water jacket behind it. Do you have a small camers to use to see into the water jackets or a thickness gauge thing, (forget the name of it right now)

 

[97egl]

I did actually pop the casting/freeze plug out of the end of the head and I can see in the water jacket. It's really hard to say how much material is or isnt there tho