Gsl-Se Center Iron vs. 12a Center

[TheDriver216]

Im deciding on which way to go with a project and was wondering which Iron has more material that can be ported.. I was informed that the 12a iron can be ported farther then the Se.. any truth to this?

I want to use the Se center in a turbo Efi app and use teh Se injector bungs for my primaries and a throttle body injection for my secondaries.

Thoughts on which can be ported bigger would be greatly appreciated.

Build thread to come soon!

[Whizbang]

well if we break down that GSLSE motor tomorrow we can probably compare to the 12a visually. Not going to cut them in half though...

[TheDriver216]

Awww man, i thought thats what you bought the chop saw for?

[Whizbang]

if we had another 12a center plate and a BAD gslse center iron, that would be another matter.

[Rogue_Wulff]

As a general rule, most 6 port center irons have less available area for porting than the 4 port center irons. If you look at the 6 port center iron, and compare the stock ports to a 4 port iron, you would see the 4 port has larger ports to start with. This tends to support the idea that a 4p center can be ported more, since there was less casting needed around the ports on a 6p center.
This is not a "Hard" rule, but is the general findings of many engine builders. Even RB makes mention of this on their website, in the porting area.
It is entirely possible that *some* 6p center irons can be ported to the same extent as a 4p center, but most cannot. The 6p center didn't need the ports to be as large, since the secondaries were so much larger total area compared to stock 4p secondaries. This also allowed for an improved idle quality on the 6p engines, in spite of the more aggressive overall port design, and resulting higher HP.

[el canito rotary]

what i did with mi engine ihave gslse iron plates, i use 3 12a plate and i did a agresive street port and i use 13b housing and rotors and a 600 holley, is work pretty good so far

[PercentSevenC]

12A intermediate plates have much more porting potential than -SE plates. Only use the -SE plates if you want the injector bungs.

[RotaryProphet]

The route to go would be to either have someone with a mill machine some injector bungs into your 12a center housing, or weld some bungs onto your intake manifold.

Like I told you when you were going to buy that center housing off me, there's definitely more horsepower potential in the 12a center.

[Rogue_Wulff]

Just how much more power can be made with a 6 port 13B, using a 12A center iron? I know there isn't much to be gained by porting the end plates, but does the 12A center iron give a real power advantage?
I have a SE 6 port converted to 4bbl carb. I have no plans to rebuild it currently, but as we all know, that could change anytime since the engine has over 200K on it. I figure on doing the porting, and swapping the center iron, when the time comes. I wonder what kind of HP numbers could come from this type of hybrid?

[BigTeddy]

Mira loco...

I have gsl-se housing witht he exhaust sleeves taken out, and im running front middle and rear 12a irons ported the only thing is you have to get the racing beat holley intake mani for this setup...

And in all honest im running all motor to break in my motor running a 600 cfm holley im pushing in the ball park of 290-300 un-tunned...

[Whizbang]

what porting?

[BigTeddy]

huge street ports on the plates and huge bridges ports

[Jeff20B]

I'd only recommend a GSL-SE plate if you were EFI so the primary injectors have enough velocity to work heap big. Otherwise with a carb, use a Y plate. What you lack in low RPM veloctiy, you make up for with midrange power. Add porting and power goes up. You can't really port the SE plates much.

[Rogue_Wulff]

Jeff, any idea of how much more power can be made by swapping the center iron, and porting, vs just porting the 6p to the max that it can go?
If I ever crack open the SE engine, I plan to swap the center iron. Though, that would leave me with a totally cool looking injector blockoff, and no where to use it..... I dunno who made it, but it has the piston with a circle/slashed across the middle logo etched into it. Very noticable under the hood.

[Jeff20B]

Maybe somebody could use it. Someone like me who would like to use a GSL-SE plate in a 6 port 12A, which would be a nice port size increase over stock, but Y ports would be too big. I do have a basic injector blockoff already though.

Atkins probably made it. The design sounds familier.