S&S Cycle just dropped the next evolution of Proven Performance with the release of its all-new MK136B Black Edition Crate Engine, built specifically for 2018–2024 Harley-Davidson Softail models. Known for delivering massive displacement, bulletproof reliability, and street-dominating horsepower, S&S has raised the bar once again with this monster 136 cubic-inch Milwaukee-Eight powerplant.

At the core of the MK136B is S&S’s MKB-Series crankcase, paired with 136” cylinders and flywheels, topped off with high-flow cylinder heads featuring +1mm oversized valves and .605” valve springs. The result? One of the largest and most powerful complete crate engines ever offered for the M8 platform—built to handle serious riders who demand serious performance.

Key Highlights of the S&S MK136B Engine

• High-Flow Cylinder Heads – +1mm oversized intake and exhaust valves, longer valves for improved geometry, and .605” max lift springs for big power.

• Race-Bred Crankcase Design – Features patented dual-spray piston cooling jets, precision-machined oil scraper, and an enlarged sump for better oiling.

• Forged Pistons & Premium Components – Backed by an S&S performance oil pump, cam support plate, billet aluminum covers, premium tappets, and Champion spark plugs.

• Factory-Style Finish – Black powder coat matches Harley-Davidson’s OEM look, keeping performance stealthy while packing in serious muscle.

• Big Power in a Stock-Height Package – Retains stock engine height for straightforward installation while delivering a massive displacement boost.

MK136B Black Edition Models

• Race Only Model – MK136B Black Edition Engine w/ 550G Gear Drive Cam (Part #310-1295) – MSRP: $12,495.95

• 49-State Compliant Model – MK136B Black Edition Engine w/ 475G Gear Drive Cam for 2018–2020 M8 Softail (except Fat Bob, FXDR, Sport Glide) (Part #310-1296) – MSRP: $12,495.95

Whether you’re chasing the ultimate drag-strip setup or looking for the biggest, baddest upgrade for your Softail, the S&S MK136B delivers the displacement, torque, and reliability riders expect from the performance legends in Viola, Wisconsin.

Important Note: The Race Only model is not street legal and is intended for closed-course competition use only. The 49-state compliant version is available for select 2018–2020 M8 Softail models.

For riders ready to unlock the full potential of their Harley-Davidson Softail, the S&S MK136B Black Edition is the ultimate power upgrade.