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Engine Rotating Assemblies & Rebuild Kits

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Results 1 - 5 of 5

S&S Cycle M8 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).

Not Yet Reviewed

$1,559.95

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$1,643.95

S&S Cycle M8 Big Bore Cylinders

S&S Cycle M8 big bore cylinders are bolt-on sets for Milwaukee 8 models. They are available in a Wrinkle Black finish with or without highlighted fins. Select the set you would like.

Not Yet Reviewed

$391.95

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$977.95

S&S Cycle M8 128 in. Big Bore Kits

The S&S Cycle 128 in. big bore kits are for Harley-Davidson® Milwaukee Eight engines to allow you to upgrade your M8 motor to the largest bore size possible—and without required machining of your cases. So ... go big or go home! These upgrade kits are as simple as big power gets! S&S Cycle 128 in. big bore kit features: * 114 in. to 128 in. big bore kit * Bolt-on kit, the largest cylinder bore possible without requiring machining of the crankcases * Cylinders are constructed from premium aluminum castings wit cast-in iron liners * Wrinkle black finish in highlighted and non-highlighted fin versions * Easy installation; no need to bore or split existing cases—just swap the cylinders! * 4.250 in. bore, 4.500 in. stroke * Forged pistons * 11:1 compression ratio * All necessary gaskets and hardware required for installation included

Not Yet Reviewed

$1,403.96

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$1,643.95

S&S Cycle M8 Flywheel Assemblies

Crankshafts are the heart of any performance engine. S&S Cycle M8 flywheel assemblies are stronger, more durable, and trued to a spec others can only dream of. These cranks for the Milwaukee-Eight platform are the best of the best to build your high performance engine around. Available in different strokes with tapered rods or full wrist pin rods, select the M8 flywheel assembly needed for your motorcycle's engine. Features and benefits: * Available in 4 3/8, 4 1/2, and 4 5/8 in. stroke * Comes with balance gear installed for easier installation * Heat-treated 4140 material is harder and more than twice as strong as stock * Stronger assembly eliminates need to weld crankpin * S&S high-strength forged connecting rods are designed with Finite Element Analysis to eliminate weak spots and handle more power * Full width connecting rods have more material to handle higher stress * Perfect for gear drive camshafts * Consistent balance and precision machining * Capable of higher rpm--more available power

Not Yet Reviewed

$1,995.95

S&S Cycle 124 in. Power Packages with Gear Drive Cam

S&S Cycle 124 in. power packages with gear drive cam are the ideal combination of performance and savings to transform a Harley-Davidson® motorcycle without breaking the bank. Each kit is tailored with the necessary components for your specific HD® model. These kits offer significant benefits, including a substantial increase in horsepower and torque across the powerband, improved throttle response, better cam timing accuracy due to the gear drive mechanism, and a more reliable valve train compared to a standard chain-driven cam, making it ideal for riders seeking a powerful and responsive engine upgrade, especially on larger displacement bikes like the Milwaukee-Eight models. Installing a 124 in. power package often necessitates additional tuning adjustments, including adjusting fuel delivery and ignition timing to optimize performance. Select the power package with gear drive cam designed specifically for your HD® model and engine to ensure proper fitment.

Not Yet Reviewed

$3,460.95

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$3,695.95

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