Porting small block 915 j-heads

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kma

kma

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Hello over there , greetings from Sweden.
Found a interesting thread Intro to a port job by @MOPAROFFICIAL porting these heads. Hope you can chime in.
However here are some pics of my untouched heads and have some questions for them who wants to share some info. First of all how much material there is in some places before hitting water or where to grind and not to.
Hope I´m understandable.

We begin in the intake

Is this lump supposed to be flattened out like on the other side of the guide and is it enough with material?
I´d be very grateful if someone can assist with very good pictures and explainings
Off course that could be a problem if there is "secrets" that´s not supposed to be revealed.
I can take advices and pictures in private ;)
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quick answer, YES.
But I don't want to rain on Moparofficial's parade... He'll find you eventually BUMP :)
 
kma said:
Hello over there , greetings from Sweden.
Found a interesting thread Intro to a port job by @MOPAROFFICIAL porting these heads. Hope you can chime in.
However here are some pics of my untouched heads and have some questions for them who wants to share some info. First of all how much material there is in some places before hitting water or where to grind and not to.
Hope I´m understandable.

We begin in the intake

Is this lump supposed to be flattened out like on the other side of the guide and is it enough with material?
I´d be very grateful if someone can assist with very good pictures and explainings
Off course that could be a problem if there is "secrets" that´s not supposed to be revealed.
I can take advices and pictures in private ;)
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Click to expand...
You can remove the roof bump/guide kink, just know the lower head bolt that on one end of each head is what you'll go through to if you go too far or as much as the taller head bolt end. Straighten the common wall, if you go too far you get into the head bolt. Water is under the short turn/common and behind guide/around bowl. Here is a pic of what that looks like on Randalls heads.

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MOPAROFFICIAL said:
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MOPAROFFICIAL said:
And some more

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MOPAROFFICIAL said:
Will post some more.
Btw that last pic IS a finished port.
For those watching...I did initial port work, sent them off for a valve job, did not approve of said valve job...testing even showed...so i took them to my other guy who did it right. Tested them again with big improvements to all but with some needing attention with air speed issues. I widened up the area between the guide and head bolt some more on those with the low head bolt pad and thinned the push rod hole a lil more, which did help. I also exploited the cast in swail just a hair, to help speed the common wall side of the turn, equalize the middle more..as well as a angled lip where the turn comes off the common wall. Hard to explain and odd sounding I'm sure.
Click to expand...

Thanks for answering to begin with.

Are all these pictures from the tall head bolt port?

Beginned grinding in the low head bolt port. Scared as hell taking away too much going through.
Still have a small small pocket behind the roof bump. Tried to measure the material thats left and its about 0,16".
If going through are the heads shot or is it possible to fix this ?
Think I have read somewhere its fixable in some way.
Can they crack when torquing the head bolt if there is too little material left ?


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I guess this is where you meen where the water is


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But the short turn isnt supposed to be touched or ?? Maybe a hair ??

Is this bump in the floor also to be processed ??

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I really couldn't tell you how far to go and expect it to translate 100%

There is water everywhere under the entire machined deck surface of the head. It varies how thick or thin it is. You can open it up quite a bit, just that at that point...you have some areas that are maxed, thinner spots than others.
 
these are not the j heads but all the 340/360 heads water passages are pretty much the same. This will give you a better visual.
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The thing that stands out the most to me from those cutaways is how close the guide bore gets to water after drilling for a 1/2” guide.
 
PRH said:
The thing that stands out the most to me from those cutaways is how close the guide bore gets to water after drilling for a 1/2” guide.
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These are not my heads. Got the pic's from a guy that blow a hole thru the bowl and then decided to cut up the other head.
They may have been bored out for insert to be installed...........but either way, still another good reason, to run a Smaller Valve Stem, Valve.
 
Looks like they had tried welding that intake port at some point.


I hardly take much out of the exhaust port.
If they’re into the mid/high-160’s(no tube), that’s enough for over 500hp(on a suitable build)......... so I don’t worry about finding water in the ex ports.

Looks like with what I do on that side of the head I should be plenty safe.

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That was a center punch he pushed thru the crack, then he touched it with a flapper wheel and got a vary large hole!!!!!
The next picture down.


I did the same thing to my "test head", trying to open up the throat/bowl around the SSR..........mine, i just covered up with green epoxy and moved one.:D
This is the other half of that port.
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Got a little too greedy I guess.

I wonder if it was just an odd void in the casting.
Seems like the whole area around the hole is paper thin.

Maybe the head had some core shift and they also got after it a bit too much.

I ported some BB stage V heads once, there was a void in the casting in an area that specifically showed in the instructions they had added material there for porting.
As soon as I touched it with the burr it blew a hole right into the water jacket.
Sometimes **** happens.
 
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Yep last intake port on that head, and boom! he cut up that head and the head he hadn't started on so he didn't make the same mistake twice.

I talked him into snapping a few pic's for me.
 
I’ve ground thru the short turn on two SBM heads.

One was a J head that was already ported, that I was trying to tweak for the customer.
It was a small hole and I repaired it.

I had based what I was trying to do with it on what I had found working well on a core head I was messing with.
I had really laid back the SSR on that one and it was working quite well.
I never even got close to having the SSR on the J head laid back that much before I saw I had “dimpled” it.

So I took that core head and tried duplicating the short turn on the neighboring intake port.
It never even got close before a hole appeared.
The “good” port was just abnormally thick in that area, so it didn’t break thru.
 
moral of the story - go easy - do not go for every millimeter of metal removal. I installed guides for 11/32" valves, but I think the o d is 1/2", if it broke thru a little, when new guide is pressed in would it leak with 10 pounds water pressure? I doubt it
 
Just my thoughts, But, besides the SSR i think if you found water..........the train had jumped the track lone before you found water or got there.
 
If you installed 2.055 or 2.08 valves, and were trying to have the bowl be “appropriately” sized for the valve....... you’re probably playing with fire in terms of finding water....... and not necessarily at the short turn.
 
PRH said:
If you installed 2.055 or 2.08 valves, and were trying to have the bowl be “appropriately” sized for the valve....... you’re probably playing with fire in terms of finding water....... and not necessarily at the short turn.
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Good point.
 
Marcohotrod said:
moral of the story - go easy - do not go for every millimeter of metal removal. I installed guides for 11/32" valves, but I think the o d is 1/2", if it broke thru a little, when new guide is pressed in would it leak with 10 pounds water pressure? I doubt it
Click to expand...

It´s not gonna be a racecar more "hot" street. Gonna build a 318 first Later will be a 2,02" upgrade for a bigger cui

PRH said:
If you installed 2.055 or 2.08 valves, and were trying to have the bowl be “appropriately” sized for the valve....... you’re probably playing with fire in terms of finding water....... and not necessarily at the short turn.
Click to expand...

I´m going for 1,94" and 1,625" + ,100" 11/32 stems
 
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Marcohotrod said:
moral of the story - go easy - do not go for every millimeter of metal removal. I installed guides for 11/32" valves, but I think the o d is 1/2", if it broke thru a little, when new guide is pressed in would it leak with 10 pounds water pressure? I doubt it
Click to expand...
Bronze moves more from I've seen. If usage permits using steel guides...It can help keep the weep away.
 
If you’ve never done any porting, best thing is to buy and read a book on the topic, then do some practicing on a scrap head.

When you reach the point where you’re able to have the porting turn out the way you want it to, along with some degree of repeatability....... then it’s time to step up to the “good” heads.
 
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