S&S Cycle 131 in. Big Bore Kits

S&S Cycle 131 in. big bore kits are aimed at the Milwaukee Eight platform for 2017 and newer big twins—and open up a whole new level of performance for these engines. When paired with an S&S 4.625 in. stroker flywheel (sold separately), engine will be a true 131cubic inches. S&S builds their big bore kits and cranks to much tighter tolerances and with higher quality materials than the factory parts. If you're the proud owner of a Harley-Davidson® Milwaukee Eight big twin and have been waiting for just the thing to boost your M8's power—the wait is over! The S&S Cycle piston/cylinder kits will be a solid platform for massive power!

Features and benefits:

* Huge displacement increase means huge power increase
* Bolt-on kit works with stock crankcases
* 4 1/4 in. bore cylinders with a new 11:1 forged piston design
* Original engine serial numbers are retained
* Powdercoat finish match factory finish, giving the bike a "sleeper" advantage
* Includes .045 in. multi-layered steel head gaskets
* Retains stock engine height
* Includes 131 in. Cam Cover Badge
* Available with or without highlighted fins

Note: This kit must be used with S&S Cycle stroker flywheels to achieve 131 in. displacement (P/N: 320-0605, 320-0620). Show Less