Introducing the next generation of Proven Performance for your 2017 & newer H-D Touring Models, the MK136 Engine.This is the newest version of the complete crate engines S&S is known for, ready to install in your M8 Touring bike. We took our MK-Series Crankcases, married them to the 136” cylinders and flywheels, and then fit High-flow cylinder heads with +1mm Valves and .605" springs. This huge displacement engine is sure to not only create huge power, but also put a huge smile on your face when you lay into the throttle. It is the purchaser's responsibility to consider the suitability for their application. Engine noise and damage from abuse is not covered under warranty.


  • 2017-2023 Harley-Davidson® M8 touring models (oil-cooled)

Features & Benefits

Cylinder Heads

  • High-flow cylinder heads with premium seats, guides, valves, springs, and seals
  • +1mm oversized intake and exhaust valves
  • Valves are .030” longer than stock for improved valve-train geometry
  • .605” max lift valve springs
  • High-strength alloy used in cylinder head casting, improved strength at high temperatures
  • Enlarged cooling passage around the exhaust seats • S&S Exclusive breather boxes


  • Forged pistons
  • S&S performance oil pump and cam support plateP
  • Premium tappets and tappet cuffs
  • Billet aluminum covers • Sprocket shaft spacer included
  • Champion spark plugs • Retains stock engine height
  • Includes Cam Cover Badge
  • Powder coat finish matches factory finish
  • Huge displacement increase means a huge power increase


  • All premium quality components
  • Patented Dual-Spray Piston Cooling Jets
  • Precision machined oil scraper
  • Enlarged oil sump
  • Contoured floor allows oil to easily drain back to the sump

49-State MK136 Engine Calibration Information