CNC Ported 55mm Intake Manifold / '17-'24 M8

S and S Cycle's 5-axis CNC ported manifold, opening up the path between a 55mm throttle body and the heads on a Milwaukee-Eight.

The intake manifold is the last thing air passes through before the head, and the stock casting is shaped for production cost as much as for flow. S and S machines this one on a 5-axis CNC so the bore and the runner blend are cut rather than cast, which cleans up the transition into the port and keeps the air moving in the direction it is already going. The black textured finish is not only cosmetic: the surface area helps fuel dissipate and atomize instead of pooling on a smooth wall.

Features of the CNC Ported 55mm Intake Manifold

• 5-axis CNC ported for maximum flow and aerodynamic efficiency
• Black textured finish that encourages fuel dissipation and atomization
• Fits all 55mm throttle bodies
• Works with stock heads and with ported heads
• Intake seals included
• Made in the U.S.A.

CNC Ported 55mm Intake Manifold Fitment

• '17-'24 Harley-Davidson Milwaukee-Eight

Not for '23-'24 FLHXSE and FLTRXSE, or '24 FLHX, FLTRX and FLTRXSTSE.

⚠️ VERIFY your throttle body size before ordering. This manifold is cut for a 55mm throttle body, and a stock M8 does not leave the factory with one on every model. S and S lists this part as 49-state federal emissions compliant; confirm what applies where you ride and register the bike.

Common Questions About the CNC Ported Manifold

Do I need ported heads to use it?
No. S and S lists it as compatible with both stock and ported heads. Ported heads let it do more, but it is not a requirement.

Will this alone make power?
It is one part of an intake path. It pays off alongside a 55mm throttle body, an air cleaner that can feed it and a tune. Bolted to an otherwise stock setup the gain is small.

Are gaskets included?
Intake seals are in the box. Reuse nothing on an intake joint; a leak here shows up as a lean condition, not as a noise.