Need some brainstorming

[bruce]

I've been working my way back through my intake tract and have come to the carb venturi. I have the rest of the intake working quite well and the venturi has now become the limiting factor.

I am limited to a 1" venturi it is currently dropping flow down 4 cfm's from the rest of the intake (I know this since I was testing using a 1.2" venturi carb) My question is this what effect does the angle on the backside of the venturi have on flow? I was using a 15* angle out of the venturi I'm planning on playing with this angle to see what effects it has on flow. I'm just curious what others might think? I will also be playing with various approach angles to the venturi. I machined up a dummy carb body so I can slip different designs in and out to test the effects . . . I'm sure it will all come own to testing but I was just curious if anyone would have any ideas for me to try . . .

[Christian]

[color=#000000]Yes there might be a clue, if i understood you right. There was "extensive" testing done by Bmw in the 60

[Kyrasis6]

I would try to play with angles between 45 and 52 degrees comming out the bottom of the venturi. Also going into the carburetor there are modifications you can make in the air breather that can increase flow into the intake. If the filter element is fairly open placing a flat ring around it will help create a venturi effect. I think it needs to be placed about an inch away from the element, also in the filter bonnet you can create a form that goes directly over the top of the carburetor to help guide the air towards it. If the bonnet is round a funnel shape should work good, if it is square more of a wedge shape should work.

[Thomas Vaught]

The transition from the venturi to the throttle body blade hole is very important for flow recovery.

The angle for a Holley 4 barrel carb is very good and basically stays the same as the venturi gets larger with a corresponding increase in the blade diameter.

Hope this helps.

Tom V.