Alphabet Engine Intake Trumpets

Adam Bahret
Adam Bahret
Screen Shot 2022 08 22 at 10.00.06 AM

A functioning assembly of intake manifold, throttle bodies, and intake trumpets is complete. The four main components are the lower aluminum section’s “intake manifold.” This is a CAD-designed and CNC-machined aluminum piece that gets the air from the throttle bodies to the engine head. It’s based on the design of my 1973 which held a set of Weber carbs on top. The second section includes the motorcycle throttle bodies, what this project is designed around. The top, black and silver, are the air intake “trumpets.” To date, this is where the most engineering has gone in this project. but you aren’t seeing the results from this hard work in this picture. Fluid dynamics are a cruel mistress. When you get them right, it’s amazing how all the potential that the motor has is unlocked. However, when you get them wrong, it’s like tying Usain Bolt’s shoelaces together.

What you see in the picture isn’t success it’s is a major road block. Those two pieces, the black base and silver trumpets, should be one piece 3D printed in ABS. But we couldn’t get the trumpet design to come together.

The shape we needed that would have the correct airflow characteristics, fit, and could integrate the air filters didn’t happen. Every 3D print of what we thought would work, just didn’t. So, for now, I purchased a set of generic metal spun trumpets that will at least let me test if the other parts work until I can work out my design. You might think they look pretty, but they taunt me as a sparkling reminder that the design process is iterative.

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