S&S Cycle MK136B M8 Crate Engine for 2018-2024 Oil-Cooled Harley-Davidson Softail
Oil-cooled Softail owners looking for the most decisive engine upgrade available now have a purpose-built answer in the S&S Cycle MK136B Black Edition. It delivers a fundamental shift in how your Softail pulls, responds at full throttle, and behaves under hard acceleration – the kind of change that completely reframes what you thought the platform was capable of delivering.
Key Features
- 136ci (2229cc) M8-based Softail-specific crate engine built around a gear-drive cam system
- Black Edition finish specifically engineered for the 2018-Up Softail chassis dimensions and mounting points
- Available with 475G cam (49-state, 2018-2020 Softail) or 550G cam (race only, 2018-2024 Softail)
- Direct replacement for the factory M8 Softail engine – bolt-in fit using existing chassis mounting
- Backed by a one-year S&S Cycle parts warranty and full technical support
Technical Specifications
- Displacement: 136ci (2229cc)
- Engine Architecture: Milwaukee-Eight based, air-cooled (oil-cooled)
- Cam Drive: Gear drive
- Finish: Black Edition
- Cam Options: 475G (49-state, 2018-2020 specific Softail models) or 550G (race only, 2018-2024 Softail)
- Warranty: One-year S&S Cycle parts warranty
Fitment Notes
- 475G cam version fits 2018-2020 oil-cooled Softail only; excludes Fat Bob (FXFB/FXFBS), FXDR, and Sport Glide (FLSB)
- 550G cam version fits 2018-2024 oil-cooled Softail; race/track use only – not street legal
- Requires oil-cooled M8 Softail chassis – not compatible with twin-cooled configurations
- A fuel tuner is required for proper calibration after installation; not included
- Review the Fitment tab for complete year and model breakdown
