Flathead 4 barrel intake port help please

[Ol' Ron]

K I'll keep that in mind.
Gamp

 

[51 MERC-CT]

The drawing indicates a divider between the front and back of the manifold, which is not accurate. The green and yellow lines are all one passage. The red and blue lines are all one passage. Since only one cylinder at a time is drawing on any one passage both barrels in each passage feed all cylinders in that passage.

Suggest you read post #14 as to the orientation of the chambers.

There are (2) left and right chambers.
One chamber services cyl's (2,3,5,8) the other (1,4,6,7) and each chamber is serviced by (1) injector.

 

[Mart]

If you remember that a four barrel operates on the primaries then kicks the secondaries in when necessary, then the diagram above illustrates the idea well. Two barrel manifolds are the same except only one venturi feeding each side.
If you say the firing order in your head and look at the diagram you can see each cylinder in the firing order draws from the opposite side of the manifold to the previous cylinder.
Mart.

 

[Nailhead Jeff]

The GM stuff might be cheap but have you considered a Holley Sniper? They work great

 

[Kilohertz]

If you say the firing order in your head and look at the diagram you can see each cylinder in the firing order draws from the opposite side of the manifold to the previous cylinder.
Mart.

Thanks Mart,

And that is exactly what I was hoping for, as the fuel injection alternates the injector pulses side for side, and as it turns out, is working very well for me so far. I just welded up a temporary exhaust from the headers so I can mount the O2 sensor and start gathering data and tune the ECM. Lot's of fun.

As for the Holley Sniper, anything from the US costs us double by the time it gets to Canada, the GM stuff is easy and local and has been working for 30 plus years, and LOTS of guys out there to help with tuning, but thanks for the idea.

Cheers