S&S Cycle Cylinder & Piston Kits — Harley-Davidson Electra Glide, Softail Heritage Classic, Electra Glide Classic (1955-2026)

S&S Cycle 136 cubic inch cylinder and piston kit for Harley-Davidson, delivering a bolt-on displacement increase from stock with a 4.320" bore. Retains stock engine height and works with existing crankcases, making it a straightforward power upgrade.

Features

• 4.320" bore for 136 cubic inch displacement
• Powder coat finish matches factory appearance
• MLS multi-layered steel head gaskets included
• Retains stock engine height and serial numbers
• Works with stock crankcases
• Includes S&S Cam Cover Badge

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 910-0850
• Displacement: 136 cubic inches
• Bore: 4.320"
• Weight: 29.75 lb
• Category: Engine Components / Piston Sets - Powersports

Fitment

Fits Harley-Davidson models with compatible stock crankcases.

Frequently Asked Questions

Will this require internal engine modifications?

No — the kit works with stock crankcases and retains original engine height, minimizing internal machine work.

Do I need to change my engine serial number?

No — original engine serial numbers are retained with this kit.

What's included in the box?

Cylinders, pistons, MLS head gaskets, mounting hardware, and an S&S Cam Cover Badge.

Will I need to rejet my carburetor or reprogram fuel injection?

Yes — the large displacement increase will require carburetor or EFI tuning to run properly and avoid running too lean.

Is professional installation required?

Installation requires engine disassembly and machine work. This is not a bolt-on kit — have a qualified shop handle the install.