Head Porting basics

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splitter,you've been given all the info you need so all I'm going say is sit down with a pen and paper and write down all the pertinent info that is on your thread.don't be afraid just be carefull. figure 40hrs to do this.buy a cheap air die grinder and go to it. I've found those that do this for the first time either run out of patience and rush it or just get tired.
 
The pushrod pinch is the SMALLEST point in the entire intake tract. Forget the flow bench...making the pushrod pinch large will help HP at all levels in this case. Just don't break through if you can help it.
Also if you open up the SMALLEST point (pushrod pinch) you'll help airflow down the port and that will help get air to turn at the short turn.
 
ou812 said:
The pushrod pinch is the SMALLEST point in the entire intake tract. Forget the flow bench...making the pushrod pinch large will help HP at all levels in this case. Just don't break through if you can help it.
Also if you open up the SMALLEST point (pushrod pinch) you'll help airflow down the port and that will help get air to turn at the short turn.
Click to expand...

What he said. You are much better off doing a very little as a gasket match and smoothing the inside radious of the pinch until you're past the casting roughness plus a little than doing anything in the bowl or removing the guide boss and have a performance 5 angle valve job done by a competent shop.
 
1wild&crazyguy said:
The smallest point is between the top of the short turn and the guide area.fyi
However, in a magnum head the PR pinch probably is the smallest point.
Click to expand...
Justin,
When i cut up my mold and measured it,........You are right, but with the porting that i have done so far..........i thing the prp is the smallest point now.

I need to pour me a new mold, of this port. If for nothing else, but to see my progress.

Have enough to make me, maybe 2 more molds.
 
1wild&crazyguy said:
The smallest point is between the top of the short turn and the guide area.fyi
However, in a magnum head the PR pinch probably is the smallest point.
Click to expand...

FYI, I was already talking about his current port. You guys crack me up....LOL!
 
Heres my "302" smogger head intake ports:

360stuff006.jpg


the port on the left is obviously in its stock form, while the port on the right is only half done. Dont mind the metal
gasket, its only there for a vague reference. I'll try to did up some more pics of the step by step process.. and also
the flow sheets. should apply to almost any cyl. head.
 
Well, since the last picture, i got my port to flow 267 cfm, was vary happy! decided to do some final touch up work, like a little bit more smoothing of every thing and un- shrouding the 2.02 valve.

Got the combustion sharp edges remove, make my bore so could un- shroud the intake valve.............when two far and took out my seat:angry7:

what i thought was .006" was actually .015" before i had a 45* seat all the way around, again.

The cfm, that i was amaze to even have! Got flushed down the toilet.
Lost flow from .100-.500 lift. at .500 lost almost 30 cfm:angry7:

So I when after my head again, with the die grinder widened my ssr, remove a lot of metal from the prp wall:)angry7:) and laid back my ssr.

DSCN1428.jpg


Well after some epoxy work to fill the hole, in the bottom there.

I have my 267cfm back..........but it's at .600 lift instead of .500 lift

From .100-.400 lift, I'm still behind in cfm............................

The hole you see there was easy to fix..........but it would have been, much easier, to have used my finger and thumb, to stop me! Before making the hole in the first place!

With winter coming, my days of grinding, and flow bench testing are numbered, and i pushed, when i should not have! Made mistakes!

Now i need to set back and evaluate this hole thing. Pretty sure i will be adding some "Zspar" Puddy to this port before I'm done.
 
Is into the water or open air?

Is that on all ports or just one?
still good numbers, but what are the .200-.450 lift #'s?
So looking back and knowing now what it takes, not too hard huh?

I love these heads.
 
1wild&crazyguy said:
Is into the water or open air?

Is that on all ports or just one?
still good numbers, but what are the .200-.450 lift #'s?
So looking back and knowing now what it takes, not too hard huh?

I love these heads.
Click to expand...

The hole was in Open air or oil side.

All my tests have been at .100 increments

56/129/193/238/265/267 this is what it is right now(representative of picture above)

Before i messed up the seat or, my best numbers were.
61/131/193/240/267/264

I have only done one intake port all the rest still are at my 15 year a go bowl porting state.
 
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