Porting small block 915 j-heads
- Thread starter kma
- Start date
-
Marcohotrod
Well-Known Member
smooth roughness and bumps and lumps and blend to the 60 or 70 degree angle. raise and widen ports gently ec.
MOPAROFFICIAL
Oogliboogli
Being conservative when starting out, having the fear, is good.
100% I think his decision to use the 1.94 Intakes will keep him out of water too.
I've done this before. It makes easy work, and it will flow pretty well, once finished.
MOPAROFFICIAL
Oogliboogli
I or you?
Hopes for what exactly?
What is your expectation of me or anyone else here? Look at shape.... go look at race heads, that's the shape you want to emulate...then you need to learn how to tame this animal and earn what you learn.
Nobody here is going to be able to tell you...'grind x amount deep into this area of the turn then only grind this amount here, then...."
it's just impossible duder. Pics. that's what those are for, and you'll still be on conservative side. Pics make the short side look steep/stockish... like Duane Porter said in his thread.. 'the one where he wouldn't even directly answer my questions or quote and answer me'... then he edited his posts many times.. and I think I totally understand why... but guess what? I'm not criticizing you ,Duane, I wasn't there to make a pissing match, I wasn't trying to say I could do it better. People ...theyre assholes, but not everyone here is trying to show the next guy up. Some need to stop worrying about that ****. Others need to learn better delivery of their insight. Condensending gets old, eluding and never being clear..like you know some secret, is manipulation. A lot of us can do the same. Some have a pitot. some don't. It doesnt make you a better head porter, it makes things sometimes easier.
You can have the same numbers with 2 different short shapes, lengths ...Same head.
Sometimes **** strikes a nerve.
I'm not pissed off, but you got my attention and I figure I'll remind people.
Last edited:
yeah... I haven't got along with Pitot's in the past. Manometer fluid is expensive, and it takes forever to get the bubbles out. lol
I've reverted to 'flow balls' as Bettes likes to call them. Easier for me, I suppose but, still not as accurate as the Pitot route. There's some, on FABO that swear by the mighty Pitot. I have no argument with them.
I've reverted to 'flow balls' as Bettes likes to call them. Easier for me, I suppose but, still not as accurate as the Pitot route. There's some, on FABO that swear by the mighty Pitot. I have no argument with them.
PRH
Well-Known Member
So, you asked for pics of the short turn, and didn’t like my explanation as to why I dont think they’re useful...... and then go on a rant about it here?
Seems like you have a bit of a chip on your shoulder.
I’ve never claimed to be the porting authority on any type of SB Mopar head, and have come right out and said on several occasions there are plenty of other people who get better numbers from various(basically all)SBM heads than I do.
I show the before & after results, sometimes with pics, and iiwii.
The pics and numbers are there....... take from it what you can....... but I’m not trying to make those posts into “teaching moments”.
It’s just show and tell.
Just who was I trying to show up with the T/A heads flowing 250’s?
Most anyone here posting flow numbers for ported stock heads has numbers as good or better than that.
Your recent porting job post with pics and numbers has numbers for both sides of the head that are higher than what I’ve posted.
As for the editing.....
Most of the time if I’m editing a post it’s to add something I either forgot, or felt the extra info would clarify the point I was making.
Or I’ll reword something I said because after reading it back, it didn’t come out right.
Lots of spelling corrections too.
I edit most long posts...... often several times.
And this one is no different.
Last edited:
PRH
Well-Known Member
As for advice for the OP........ porting is an acquired/learned skill.
Just like learning to paint pictures or play a musical instrument.
Reading about it and getting some instruction is really just scratching the surface on acquiring the skills to be any “good” at it.
To see if it’s something you have a knack for, there’s no substitute for getting your hands dirty.
Just getting started in on doing it, and without being able to do any testing, it’s generally best to follow the “less is more” motto.
Focus on quality rather than quantity(how well it’s ported, not how much it’s ported).
Although, with typical SBM stock heads, minor reworking of the bowl and SSR will only get you so far.
And then you have to start going after the guide boss and pinch area to start seeing more substantial gains.
The 1.94 intake valve is a good place to start, since it will take less material removed from the SSR to achieve a proper shape(than if you used a larger diameter valve).
Just like learning to paint pictures or play a musical instrument.
Reading about it and getting some instruction is really just scratching the surface on acquiring the skills to be any “good” at it.
To see if it’s something you have a knack for, there’s no substitute for getting your hands dirty.
Just getting started in on doing it, and without being able to do any testing, it’s generally best to follow the “less is more” motto.
Focus on quality rather than quantity(how well it’s ported, not how much it’s ported).
Although, with typical SBM stock heads, minor reworking of the bowl and SSR will only get you so far.
And then you have to start going after the guide boss and pinch area to start seeing more substantial gains.
The 1.94 intake valve is a good place to start, since it will take less material removed from the SSR to achieve a proper shape(than if you used a larger diameter valve).
Last edited:
100% there's a such thing as learning to crawl. I have more respect for those wanting to learn, and proceed cautiously, than those who strut around and speak of their skills.
To those, I always say, "you should never touch a burr or sanding roll to a head, without a flowbench" It usually pisses them off, but I don't care given their attitude.
I don't say this flippantly, I had to go through the process too. It's hard on the ego, but the rewards are great.
MOPAROFFICIAL
Oogliboogli
Nobody was, or is, trying to show up anyone else.. that's the point...if you re read it..im telling YOU to not think that's what up. Now here you are with reasons, unnecessary. Look when I see you avoid ever directly responding to any question or even compliment from me... that's the vibe I get, defensive or rude. Don't act oblivious, don't spin it. It's your actions, just rewind and look. Everyone here knows that only about 35% of the board can spell ...lol or even gives a rats ***... so pffft with that. We've all come to learn to translate the short comings and hastely typed.
Hey I asked you about air speed, you ignored it. I asked you about port volume, you ignored it. I said good job 'it takes skill' aka-you have skill, you ignored it. What a gentleman, how corgile as a fellow head porter, right?. That's what I was talking about... not trashing your skill or your work.... If I thought a person sucked, I wouldn't even read their post...i will even do like you did on Jesse's thread maybe start posting my own pictures and stuff of my work LOL
"Whom I'm I trying impress with 250's"
Who spoke il of that? You received nothing but praise. Why would you even mention that?
Maybe because...
I do remember seeing a slew of your ******* replies on Jesse's stock 340 thread pushing for a stroker , pushing for better head, pushing for all kinds of ****...till someone, hi , pointed out that you WERE hijacking , that you WERE saying you could do it better your way..and Jesse straight said the customer was reading the replies. Class act. Lol no big in the end, oops...uh oh spaghetti'O... benifit of the doubt, unintentional I'm sure...since you did recognize and stepped back.
So don't act like you weren't stirring someone else's cool aid, like maybe you are on the defense for those like yourself, right? Wink wink.
MOPAROFFICIAL
Oogliboogli
I have a single 587 here that's 1.88, been thinking about sectioning up the intake ports as a whole and if you wanted to pay shipping I could ship you a ported intake port in a little box that you could try and emulate yourself. Fyi you can lay that 1.88 back quite a bit compared to 2.02 because obviously you leave a lot more material in the short turn by not opening it up to 2.02...you van also see a good 250cfm with 1.88, but the low lifts are not quite as big as the 11/32 stem 2.02. The 1.88 is just too big in regards to the under head and stem. The 1.94 11/32 is a better shape and the low lift numbers can improve by 4-6cfm by just the valve change...but could also affect the higher lift air speed and flow, increase in both could lead to turbulence with a lil higher number right before it jumps ship on you...in which case you need to better equalize the short turn so the stronger high speed side does not yank from the weaker lower speed side.
Last edited:
PRH
Well-Known Member
So, this thread is about head porting of SB heads, but you feel the need to bring my name up, then go on to say:
And you wonder how I came up with that being directed at me?
And you wonder how I came up with that being directed at me?
Hey guys
I´m beginning to feel that I have started something bad here that was NOT my intention
@MOPAROFFICIAL your comment "love to see this stuff" made me a little confused what to think. My answer was not meant to stir up emotions in any way (Google translate)
If we had been standing eye to eye IRL discussing head porting and you said those words I would have put my hand on your shoulder and said my comment with a smile. More as a joke
No intention making you upset. Hope we can put this behind from now on
I´m listening to you guys and and suck it in. I realize there is a whole lot of experience involved and I just want to suceed with good numbers as a beginner. Not shooting for high score but some decent flow would be nice.
Therefor I am
1. cut up a 587 head in pieces , got a cracked one from a friend. The big question here is: big diffrence in casting? anyone who knows? the bump under the lower head bolt look the same
2. somehow try to figure something out to measure the flow and compare changes just learned about Pitot from you guys but flow balls??? ha ha Is that for real?
Thanks for now and PEACE
I´m beginning to feel that I have started something bad here that was NOT my intention
@MOPAROFFICIAL your comment "love to see this stuff" made me a little confused what to think. My answer was not meant to stir up emotions in any way (Google translate)
If we had been standing eye to eye IRL discussing head porting and you said those words I would have put my hand on your shoulder and said my comment with a smile. More as a joke
No intention making you upset. Hope we can put this behind from now on
I´m listening to you guys and and suck it in. I realize there is a whole lot of experience involved and I just want to suceed with good numbers as a beginner. Not shooting for high score but some decent flow would be nice.
Therefor I am
1. cut up a 587 head in pieces , got a cracked one from a friend. The big question here is: big diffrence in casting? anyone who knows? the bump under the lower head bolt look the same
2. somehow try to figure something out to measure the flow and compare changes just learned about Pitot from you guys but flow balls??? ha ha Is that for real?
Thanks for now and PEACE
Ok but how does that work ??
I have no idea. Never seen or heard about
Well, it's a flowbench tool, or flow tool while the head your working on is in action on the flowbench.
In Harold Bettes book Engine Airflow, Harold goes through detail on how to use it.
Several years ago, Harold was at my buddies shop, and he gave us a personal tour of the Flow Ball.
With the bench on, poke the FB (flow ball) in the port, and observe the % of flow manometer.
If the flow improves with this FB in any region of the port, two things have been realized, either the ball is taking up area in the port that is too big, where the presence of the ball 'stuffs' port area and increases velocity, therefore airflow.
OR you have disrupted airflow to a compromised region downstream of the ball. Usually in the Short Side Radius, or Short Turn Radius as some call it, or possibly the guide area. Meaning, airspeed has been slowed just enough to allow a smooth transition in these areas and temporarily increasing airflow.
IF the % of flow manometer showed a decrease of flow, you have placed the ball in a very high velocity area, therefore disrupting laminar airflow, and or taken up space in a region that is probably already too small.
It is up to the user to distinguish the scenario and make adjustments in the port. IE modeling clay can be placed within the port that is suspected to be too large and retest, Etc.
It goes deeper than that, but yo get the idea..
PRH
Well-Known Member
I’ve never seen the books on hot rodding SB Mopars, so I don’t know how much detail they give with specifics about the heads.
Of the various heads I’ve ported from other makes, which is fairly limited I’d say........ the SBM are somewhat unique, in terms of some of their quirks.
Its not that they’re really all that hard to do, and if one had some previous porting experience on other typical OHV V8 heads, much of the same principles apply.
If you don’t have any real experience, and can’t test....... then my suggestions would be........have someone with experience and/or the capabilities to test do one intake/exhaust port on a junk head that you can use as a template to copy.
Or, if they can’t test, but are pretty experienced....... that could still be an option too.
Practicing on the scrap head should give you an idea of how much time will be required for the amount of modification you decide to do.
I’ve seen it where someone starts out with grand intentions...... but by the time they get to the last few cylinders, they just want them done....... and you can see the enthusiasm for grinding on iron has fallen off.
This again falls into that “less is more” mantra.
Personally, I’m a big proponent of getting “the most for the least”.
The most gain, for the least work.
And..... just remember, if the overall combination is good, the car can still go quite well with minimally ported heads.
As an example, my car was running low 11’s with a 383 and unported 906’s(230’s cfm).
The part of the “acquired skill” pertains to your ability to make the port, the shape you want it to be.
Even though when watching someone porting, it looks like one is just letting the grinder flail around inside the port...... it’s actually controlled chaos, and it does take some practice to make the port the same as the shape it is in “your minds eye”.
So theres(at least) two parts to the learning curve........
One part is the understanding of how to reshape the port to get it to flow enough to reach the desired goals for the build.
The other is learning how to physically do the manual labor, and then which tools and techniques are required so you end up with the finished product being what you set out for it to be.
For myself, after I had messed around with it for a couple years, and occasionally having a head tested........ I decided I really needed a way to test/validate the work.
So, I bought a small flow bench. That was 1992.
Of the various heads I’ve ported from other makes, which is fairly limited I’d say........ the SBM are somewhat unique, in terms of some of their quirks.
Its not that they’re really all that hard to do, and if one had some previous porting experience on other typical OHV V8 heads, much of the same principles apply.
If you don’t have any real experience, and can’t test....... then my suggestions would be........have someone with experience and/or the capabilities to test do one intake/exhaust port on a junk head that you can use as a template to copy.
Or, if they can’t test, but are pretty experienced....... that could still be an option too.
Practicing on the scrap head should give you an idea of how much time will be required for the amount of modification you decide to do.
I’ve seen it where someone starts out with grand intentions...... but by the time they get to the last few cylinders, they just want them done....... and you can see the enthusiasm for grinding on iron has fallen off.
This again falls into that “less is more” mantra.
Personally, I’m a big proponent of getting “the most for the least”.
The most gain, for the least work.
And..... just remember, if the overall combination is good, the car can still go quite well with minimally ported heads.
As an example, my car was running low 11’s with a 383 and unported 906’s(230’s cfm).
The part of the “acquired skill” pertains to your ability to make the port, the shape you want it to be.
Even though when watching someone porting, it looks like one is just letting the grinder flail around inside the port...... it’s actually controlled chaos, and it does take some practice to make the port the same as the shape it is in “your minds eye”.
So theres(at least) two parts to the learning curve........
One part is the understanding of how to reshape the port to get it to flow enough to reach the desired goals for the build.
The other is learning how to physically do the manual labor, and then which tools and techniques are required so you end up with the finished product being what you set out for it to be.
For myself, after I had messed around with it for a couple years, and occasionally having a head tested........ I decided I really needed a way to test/validate the work.
So, I bought a small flow bench. That was 1992.
Last edited:
This is case and point as to why none of us can point to where to grind, aside from the basics of general good shape, to anyone. There comes a point, careful testing is imperative.
And when you're dealing with 40 -50 yr old castings with sometimes wild core-shift, this is compounded.
And when you're dealing with 40 -50 yr old castings with sometimes wild core-shift, this is compounded.
PRH
Well-Known Member
I agree.
Though, After you’ve done it “for years”....... and especially on heads you’re pretty familiar with....... one should be able to produce pretty good results, with reasonable repeatability, without having to do testing.
I’m talking about basic bowl blending, pinch work, guide trimming, etc........ not high effort jobs.
For basic jobs like that, for me the flow test is really just a “verification” of the work.
PRH
Well-Known Member
If you find yourself actually enjoying the process of reworking heads, and end up doing it semi-regularly....... there are some reasonably affordable diy flow bench kits that use a shop vac for the flow source.
Plenty of examples of them on line.
Plenty of examples of them on line.
PRH
Well-Known Member
Here’s a case of less is more......
Someone who is a very talented head porter, with way more insight and vision as to what it takes to get a head to really “work” than I have, got a hold of me about some heads he was messing with....... that he hadn’t fooled with before........ but he knew I had.
He had really gone after it....... but the results were not representative of the effort.
He sent me several pics and flow data.
He had done waaaay more porting on them than I ever had, but the numbers weren’t showing it.
My answer(for the most part), based in part on my lack of enthusiasm for grinding that much metal out of a head was....... don’t try and re-engineer the ports that much.
Despite the port being relatively lazy with an oddly shaped SSR....... they work better than you’d expect, when you just kind of fix the easy stuff.
On both sides of the head.
So....... that’s what he tried, and he ended up with a better number....... with way less work.
I have no doubt he would have gotten there eventually........ but I’m sure I helped expedite the process....... on that head.
Sometimes...... less really is more.
Someone who is a very talented head porter, with way more insight and vision as to what it takes to get a head to really “work” than I have, got a hold of me about some heads he was messing with....... that he hadn’t fooled with before........ but he knew I had.
He had really gone after it....... but the results were not representative of the effort.
He sent me several pics and flow data.
He had done waaaay more porting on them than I ever had, but the numbers weren’t showing it.
My answer(for the most part), based in part on my lack of enthusiasm for grinding that much metal out of a head was....... don’t try and re-engineer the ports that much.
Despite the port being relatively lazy with an oddly shaped SSR....... they work better than you’d expect, when you just kind of fix the easy stuff.
On both sides of the head.
So....... that’s what he tried, and he ended up with a better number....... with way less work.
I have no doubt he would have gotten there eventually........ but I’m sure I helped expedite the process....... on that head.
Sometimes...... less really is more.
-
