S&S, big bore M8 136" cylinder and piston kit. Black fins

2222cc kit. Cylinders with wrinkled black finish and black fins (non-highlighted). The kit includes a 4.320" forged big bore piston kit, 4.320" big bore cylinders with wrinkled black finish, 2 x .030" multi-layer steel head gaskets, 2 cylinder base gaskets, 4 cylinder alignment pins, 2 exhaust gaskets and an S&S cam cover for cubic inches. Compatible with stock crankcases; no crankcase machining required. 4-5/8" stroke engine flywheels are required, which must be purchased separately as 923271.
Note: S&S measured 150.5HP and 147.5TQ with a 590 cam, CNC heads, large bore throttle body and a high-flow Stealth air filter kit.
Note: Fully assembled 4-5/8" stroke flywheel assemblies are required for installation of this big bore kit. Available as 923271 (without compensator gear). Comes with full-width wrist pin connecting rods, required for S&S pistons.
Note: The S&S 576972 extra strong cylinder head bolt kit or similar is recommended.
Note: Fuel injection and ignition adjustment is required.
Note: S&S does not recommend this kit for use on Tri-Glide or other trikes, including conversions, due to the forced-work nature of these motorcycles.


Specifications


Brand
S&S


Application
17-25 M8 models (excl. 2025 Softail; 23-25 CVO; 24-25 FLTRX; 24-25 FLHX; 2025 FLHXU; all Trikes) (NU)


Sales unit
Kit


Colour
Black


Material
Multi-Layer Metal


Finish
Wrinkle


Packaging weight
13.1 kg


HS Code
87141090


Motorcycle family
SOFTAIL, TOURING


Original name
S&S, M8 136" big bore cylinder & piston kit. Black fins