I was just looking at some G heads sitting on my bench and was wondering why you could not remove the separations between the intake ports as far as possible in the heads and have an intake with no separations, just four large runners in a single plane design.

Would it mess up the velocity of the flow or what???

I would think you could get huge flow numbers this way where the separation  to each cylinder is minimized.

Has anybody tried it??

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

No Comments on this???

I was looking at a 6 X 2 manifold on Epay and they have no separation between ports so the separation starts at the head.

Whats your thoughts???

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Bill:

I would be surprised if anyone has tried this and can document whether or not it worked.  I once made an open plenum manifold from an ECZ-B and it caused a midrange miss that didn't go away completely at high rpm.  Putting a fore/aft divider in the plenum cured the miss.

John

John - "The Hoosier Hurricane"

How do the 6 X 2's perform?? anyone have experience with them?

I have several pairs of small valve heads and am almost tempted to try it, I've ported several snowmobile cylinders but no auto heads yet. I think it would let the heads breath like stink. Maybe 4 holley 94's, one over each port on its own runner?

The only thing I am thinking is that the ports would be too big and not keep the mixture in suspension by not having enough velocity??

But we won't find out unless we try, right!

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Runner length as well as runner size is key to low end torque production.  If the runners are shortened and/or enlarged, then flow velocity is slowed and especially at low rpm.  This can allow reversion within the runners to take place which in turn upsets the flow going to adjacent cylinders.  The longer the intake duration or the later the intake valve closes, then the more sensitive to runner length the engine becomes.  On the Y, this seems to show up first in cylinders 1 & 2 when experimenting with runner lengths.  This actually makes sense when looking at the Y firing order and seeing that both 1 & 2 fire next to each other while also being paired together on the head.

 

In a blown application, the runner length is not as critical due to the positive pressure that’s always present at the intake valves.  But in a normally aspirated engine where the individual cylinders are constantly pulsing at different pressure differentials, then the runner length helps to equalize all these differentials under the carb.

 

So to answer your question, Yes, the flow would be upset.  More so at low rpm and less at high rpm.  The latest in head technology is putting a big emphasis on big flow numbers with small ports.  This is being done by keeping the flow more laminar and less turbulent.  Bigger is not necessarily better when it comes to flow especially on small cubic inch engines.

 

In regards to removing the dividers in the heads, I’ve actually talked to someone that’s done this to both the heads and intake and they commented that it was extremely lazy on the low end.  Would run okay at the higher rpms but was extremely sluggish on the bottom end of the rpm scale.  The 6X2 setups would fall into this particular category.

Lorena, Texas (South of Waco)

Thats kind of what I suspected and I wasn't thinking about 1 & 2 cylinders firing next to each other. Ideally you would need each pair firing every other 360* from each other, which would involve playing with cams, firing order and maybe crank rod throws to get it balanced out. Thats way out of my capabilities.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?