Velocity stacks has two main purposes. First one helping into frequency(resonance) tuning of the engine. They can be easily changed, thus altering the length of the inlet tract. The second one is to smooth the air flow into the carburetor or the induction system of a EFI system.
For the DCOE type of carburetors there are two construction: flanged and slip.
Example of flange type:
Example of slip type:
I can provide both types in different sizes and lengths, custom dimensions are also accepted. All of them are sand cast and machined, not like the most cheap out there. The casting process allow us to make the curvature very gentle, which will minimize the flow separation and increase the intake charge going into the tract.
Common available size length wise are:
Other area where velocity stacks are used in the intake plenums.
We can offer you 3d printing of the velocity stack or stacks that you can use to test your setup, before purchasing or ordering to be manufactured. Development of patterns and sand casting. Composite stacks.