Chev V8 Intake Theory and Routing?

[240260280z]

I was helping my dad with his '65 Impala SS today. We just wanted to set the idle.

It has Edlebrock 9906 4 barrel carb with idle set screws on each side (one for front barrel on passenger side and one for front barrel on drivers side). The exhaust is split on each side from the manifold back so there is independence.

When adjusting the carb's idle, I found that each jet affected both sides. I am guessing the intake was where some mixing was going on.

The car was also tilted ~ 5 degrees due to the floor of the garage failing (hillbilly is doing some body work where we tuned in situ).

To get balanced O2 readings on each pipe at idle, the edlebrocks needed the lower side of the tilted carb (drivers) at 0.5 turns out and the higher side at 2.5 turns out. The manual specifies ~ 1.5turns out for each side.

So:

1. Are edlebrock's fuel delivery and floats affected by the tilted car (lower on drivers side)?

2. Are 65 impala intakes not machined well enough so that drivers side and passenger side flow is not symmetrical/equal?

3. Do 65 impala intakes mix left and right barrels from a carb at idle?

4. Do edlebrock 9906 carbs mix left and right barrels at idle in the throat/base?

5. Are the idle screws on edlebrock 9906 carbs machined accurately so as to match flow at the same number of turns out?

I appreciate Japanese kit all the more after working on Detroit metal.

[Zed Head]

From my past, limited, experience with small block chevys (actually V8's in general), I remember that many dual plane manifolds don't completely separate each side I think it might be to moderate the pressure pulses or to make both sides available at high flow rates. Anyway, I don't think the sides of the carburetor are completely isolated. Some of the aftermarket manifold actually have a slot cut at the top of the divider. You can find pictures on the web. Plus, at idle, much of the fuel air mixture is just hanging around waiting for the next intake cycle, so if the sides are connected you would get some blending.

Of course, if you have a tunnel ram manifold, I think it's just one big hole under the carburetor.

Does he have headers? The chevy exhaust manifolds were pretty bad. When I replaced stock manifolds with headers, the idle smoothed out considerably.

I don't know anything about Edelbrock carbs. Actually, not much about any carbs.

[doradox]

If it's a dual plane manifold per "side" of the carb it will feed the front and rear cylinders on one bank and the middle two on the other. This gives roughly equal length runners.

[240260280z]

Thanks guys.