Magnum head porting for the beginner

[PRH]

I have basically zero Magnum Head porting experience.

I did a 5 minute blend on a set of 3.9 v6 heads for a guy I worked with....... over 20 years ago...... that’s it.

So...... what’s the story with not touching the floor?

Edit: I thought you had mentioned staying away from the floor, but re-reading it, I didn’t see it.

How long would it take you to duplicate that port?

 

['63GT]

So...... what’s the story with not touching the floor?

I fiddled with a port on the same head the week before.. any time I waved a 3/8" flowball in the floor, just past the opening, the flow went up. so, it's either too large there, or I slowed the air to the SSR.
So,consequently, when I raised the roof and filled the floor, I picked up an immediate 15 cfm, even though I actually closed down the CSA.
I didn't investigate it any further. The floor in those heads are whacky. There's a 'Rib' running down the length of the floor that traces the Turn wall..(post 16) just didn't have the gas to dissect it.
Getting hungry by then..

 

['63GT]

How long would it take you to duplicate that port?

Sorry, I didn't catch your edit..
Maybe 45 minutes to replicate..

 

[mini]

Beauty. Would love to get my hands on a flow bench. I'll get there sometime.

Thanks for the play by play!

 

['63GT]

Thanks for the play by play!

It was a pleasure. Fun too. Glad you liked it. I hope to do the Exhaust port towards the end of the week. Make sure you tune in for that.

There are some companies out there offering Flowbench kits. It's what I did.
You could use, what's called 'pass around' calibration plates to ensure your bench is reading accurately too, once it's finished.
One kit is: PTS Homepage there's a FABO member who has one of these.
I used the What It Is | Flow Quik
But mine is a far cry from the crap design they're peddling.. (see post #12)
Used SF-110's are about $3000 in the used market. Less if you're lucky.

 

[mini]

Yeup I was talking to @pittsburghracer about the PTS unit he gave me some great info

 

[Hysteric]

It was a pleasure. Fun too. Glad you liked it. I hope to do the Exhaust port towards the end of the week. Make sure you tune in for that.

There are some companies out there offering Flowbench kits. It's what I did.
You could use, what's called 'pass around' calibration plates to ensure your bench is reading accurately too, once it's finished.
One kit is: PTS Homepage there's a FABO member who has one of these.
I used the What It Is | Flow Quik
But mine is a far cry from the crap design they're peddling.. (see post #12)
Used SF-110's are about $3000 in the used market. Less if you're lucky.

You can build one much cheaper than that using Bruce's ideas and what he offers.

 

['63GT]

Part II is posted! Exhaust
Magnum Head porting for the beginner, Pt II Exh

 

[Lil Demon]

About to look up part II but I have to say this has got to be one of the highest quality posts I have ever seen on any forum. Amazing step by step analysis and great technically backed information. Great post!!

 

[Brian Hafliger]

I fiddled with a port on the same head the week before.. any time I waved a 3/8" flowball in the floor, just past the opening, the flow went up. so, it's either too large there, or I slowed the air to the SSR.
So,consequently, when I raised the roof and filled the floor, I picked up an immediate 15 cfm, even though I actually closed down the CSA.
I didn't investigate it any further. The floor in those heads are whacky. There's a 'Rib' running down the length of the floor that traces the Turn wall..(post 16) just didn't have the gas to dissect it.
Getting hungry by then..

When that happened, you directed the flow over the ST better...it's not too large. Also, raising the roof AND filling the floor will pick up flow...AND lose power! You have to know what changes you make in the ports, how they affect power. Unfortunately, it's not always a gain in power with a gain in flow. That's where the bench gets very misleading...

When we used to sell the EQ and Indy heads, we were privy to a bunch of data from both heads prepped similarly as well as ported on street strip builds, mostly 408 cid engines...Indy's always made more power, most likely due to the intake port dimensions at the short turn. Never lost HP or TQ with those over EQ's...I asked Russ if he'd considered making the X heads in aluminum, which to my surprise was a yes...but it never happened.

OEM Magnums can make great power with porting like this. It's just really impossible to get high lift from them with water under the spring pad...that was THE key to both the EQ and Indy heads...we ran most of our builds with at least .605 lift, netting at least 500HP on mild pump gas builds. Fun Fun!!

 

[rumblefish360]

Any other suggestions to this thread to the home guy?
Something easy…

When that happened, you directed the flow over the ST better...it's not too large. Also, raising the roof AND filling the floor will pick up flow...AND lose power! You have to know what changes you make in the ports, how they affect power. Unfortunately, it's not always a gain in power with a gain in flow. That's where the bench gets very misleading...

When we used to sell the EQ and Indy heads, we were privy to a bunch of data from both heads prepped similarly as well as ported on street strip builds, mostly 408 cid engines...Indy's always made more power, most likely due to the intake port dimensions at the short turn. Never lost HP or TQ with those over EQ's...I asked Russ if he'd considered making the X heads in aluminum, which to my surprise was a yes...but it never happened.

OEM Magnums can make great power with porting like this. It's just really impossible to get high lift from them with water under the spring pad...that was THE key to both the EQ and Indy heads...we ran most of our builds with at least .605 lift, netting at least 500HP on mild pump gas builds. Fun Fun!!

 

['63GT]

When that happened, you directed the flow over the ST better...it's not too large. Also, raising the roof AND filling the floor will pick up flow...AND lose power! You have to know what changes you make in the ports, how they affect power. Unfortunately, it's not always a gain in power with a gain in flow. That's where the bench gets very misleading...

Not a mystery, trust me. I just did a set of super stock SB heads with 10cc worth of epoxy in the floor to stay within the 165cc port volume (per NHRA spec) that flowed as good as the Mag port at 170cc plus and a larger 1.920 Int valve. Did I mention SB SS head has a 1.88 valve?

 

[RustyRatRod]

Not a mystery, trust me. I just did a set of super stock SB heads with 10cc worth of epoxy in the floor to stay within the 165cc port volume (per NHRA spec) that flowed as good as the Mag port at 170cc plus and a larger 1.920 Int valve. Did I mention SB SS head has a 1.88 valve?

I have to be in a particular mood to read and hang onto this kinda thing. Might be some adhd along with my dyslexia. But this is one of the few posts that has helped me actually grasp the concept of porting. Thanks. I still won't do it, because I'd cut ahead slam in half with a grinder. lol

 

['63GT]

I have to be in a particular mood to read and hang onto this kinda thing. Might be some adhd along with my dyslexia. But this is one of the few posts that has helped me actually grasp the concept of porting. Thanks. I still won't do it, because I'd cut ahead slam in half with a grinder. lol

THANK YOU!
I will wear that, as a badge of honor!
In this article, I set out to remove the mystery that has cloaked the subject of porting for decades.
While it's not for everyone, and it does require some talent, as well as a degree of aptitude.
If some basic steps are made, almost everyone can enjoy success. Not all heads are created equal, obviously..
I made my first flow test in 1991, and was hooked! And while I had access to 2 flowbenches, I HAD to have one of my own. Figured out how they worked and built my own, and in '97 bought my first legitimate one.
I entend no malice to those making a living in this arena! In the wake of manufacturers offering more and more cylinder heads, the professional porters job gets more complicated by every new product. When it becomes easier AND more cost effective to buy the latest shiny object, why would anyone choose to call a porter??
Well for the rest of the enthusiasts who can't afford either, but have the time... there remains a vacuum to be filled.
The only other reasoning is, I've seen a lot of port work, in my years, that has turned cyl heads into 50# ankors. If I can lend some help to the well meaning car nut, I'm glad to do it.

 

[rumblefish360]

I’ll say it out loud, Thanks!

Some basic techniques and easy at home work is a nice help for those wanting a little more without the need of a lot of work. It is t always a needed step. A good valve job and some minor bowl work go a long way in the street performance arena where most of us guys are.

While doing it yourself, a valve job and bowl work requires a small expense, it’s not a horrible one if your into doing this kind of work yourself.

@MOPAROFFICIAL Started right here on the FABO board with nothing by a yearning to learn and away he went!
(Share a few if ya want!)

Granted, doing your own valve job requires a machine, Ka-Ching, a die grinder is a few bucks and bigger s to grind with are a few more, flow testing requires proof of work and how that gets done is ether ka-ching or KA-CHING!!!

It can add up. Not for the average guy doing a one and done engine.

 

[Professor Fate]

That's why the old DC porting templates were such a great idea (in their day)- an easy way for the average enthusiast to get a known improvement at home.
Porting has come a long way since then, but the idea behind it remains valid- and threads like this, showing the results of '63GT 's efforts are an extension of that idea. Kudos for all your work!

 

[MOPAROFFICIAL]

THANK YOU!
I will wear that, as a badge of honor!
In this article, I set out to remove the mystery that has cloaked the subject of porting for decades.
While it's not for everyone, and it does require some talent, as well as a degree of aptitude.
If some basic steps are made, almost everyone can enjoy success. Not all heads are created equal, obviously..
I made my first flow test in 1991, and was hooked! And while I had access to 2 flowbenches, I HAD to have one of my own. Figured out how they worked and built my own, and in '97 bought my first legitimate one.
I entend no malice to those making a living in this arena! In the wake of manufacturers offering more and more cylinder heads, the professional porters job gets more complicated by every new product. When it becomes easier AND more cost effective to buy the latest shiny object, why would anyone choose to call a porter??
Well for the rest of the enthusiasts who can't afford either, but have the time... there remains a vacuum to be filled.
The only other reasoning is, I've seen a lot of port work, in my years, that has turned cyl heads into 50# ankors. If I can lend some help to the well meaning car nut, I'm glad to do it.

Every head is indeed different and can be a new challenge. For instance what makes a factory 360 head work so well ported ...does not exist in a speed master aluminum head. Most of the cheap aluminum crap flat out sucks.
Too big in the wrong areas, seat too big for how they're installed-zero shaping/transition where the cyl wall intake chamber meets the seat. Its shaped like an L . Garbage most of this crap is as if it were aimed at 4.100+ bores.
By now...you might think they would just start focusing on affordable offset rocker kits and geometry shims... just knock the pinch out and work the heads to their full potential...which is too close to whats offered out there if ya want to spend the extra 2200. I have a speed master AL as cast that flows right with everybody else's in 2 ports then 1 port over flows barely 230's, crap low lift, measures smaller about everywhere.

People take those right out the box and run them.