Velocity stacks

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:

Velocity stack with flange

Example of slip type:

Velocity stack with slip fit

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.

Cross section of the velocity stack, showing the curved profile

3D model of the casting with the pouring system

Common available size length wise are:

Velocity stacks with DCOE flange diameter 45 mm and 16 mm

Velocity stacks with DCOE flange diameter 45 mm and 26 mm

Velocity stacks with DCOE flange diameter 45 mm and 40 mm

Velocity stacks with DCOE flange diameter 45 mm and 55 mm

Velocity stacks with DCOE flange diameter 45 mm and 60 mm

Velocity stacks with DCOE flange diameter 45 mm and 75 mm

Velocity stacks with DCOE flange diameter 45 mm and 90 mm

Other area where velocity stacks are used in the intake plenums.

Other style of velocity stacks used in intake manifolds

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.