Engine Rotating Assemblies & Rebuild Kits

Eagle Street Performance Rotating Assemblies with Keith Black Pistons

Eagle street performance rotating assemblies with Keith Black pistons offer the perfect balance of strength, performance, reliability, and affordability. These rotating assemblies include a cast steel crankshaft, Eagle "SIR" I-beam connecting rods, hypereutectic pistons, rings, and bearings. Eagle rotating assemblies are test-fitted in house to ensure everything works well together. Take the worry out of your engine build project with an Eagle rotating assembly designed for your year, make, and engine application.

Not Yet Reviewed

$1,913.99

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$2,380.99

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).

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$1,559.95

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$1,643.95

S&S Cycle M8 124 in. Big Bore Kits

Inspired by S&S Pro Stock drag race engines, S&S Cycle 124 in. big bore kits utilize a ductile cast iron liner wrapped in cast aluminum for optimum thermal conductivity and performance. These bolt-in kits do not require machining, re-balancing or engine removal, and include just about everything you'll need to complete the installation. S&S Cycle 124 in. big bore kits are available in wrinkle black or wrinkle black with highlighted finned cylinders. Transform your stock engine into a 124 in. monster with the installation of a 124 in. big bore kit from S&S Cycle! S&S Cycle 124 in. big bore kit features: * Available for 107 M8 models * 107 to 124 in. big bore kit * Bolt-on kit * Includes gaskets and hardware required for installation * 4.250 in. bore * Forged Pistons * 11:1 compression ratio

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$1,561.95

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$1,643.95

S&S Cycle Twin Cam Cylinders

Boost your engine's performance with S&S Cycle's Twin Cam cylinders. The design, finish and workmanship of these cylinder replacements feature many improvements over stock units, including sturdier walls that are far less prone to warpage. Straighter, sturdier walls equals a better seal, and fit for pistons, and piston rings. An improved machining process also ensures a better surface for both the head and base gaskets. These cylinders feature ductile cast-iron sleeves in aluminum castings and are offered in silver and black wrinkle finish. Select the cylinders designed to fit your specific HD® model.

Not Yet Reviewed

$510.95

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$1,450.95

S&S Cycle 107 in. Big Bore Kits

S&S Cycle 107 in. big bore kits are easy to install and require no machining or re-balancing. These are the largest bores that can be fit in your stock engine case. This is the largest bore that can be fit in a stock engine case. Stock engine height is maintained so there are no manifold or frame fitment issues. Using an 11-fin design, the pre-finished cylinders closely resemble the OEM shape and are ready to install. Take your stock engine case as big as it'll go with S&S Cycle 107 in. big bore kits! Product features include: * CP pistons feature a 3cc pop-up dome for slightly higher compression * Cylinders feature an increased fin area for better heat dissipation * Centrifugal cast gray liner features 40,000 psi tensile strength for superior wear and performance

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$1,345.95

S&S Cycle 883 to 1200cc Hooligan Cylinder Kits

An 883 to 1200cc Hooligan cylinder kit for a Harley-Davidson®, like the ones made by S&S Cycle, provides a significant increase in engine displacement, resulting in substantially more power and torque without requiring major engine modifications, making it a popular upgrade for riders seeking better performance on their Sportster 883, with benefits like increased horsepower—by boosting the engine size from 883cc to 1200cc, the Hooligan kit delivers a noticeable power gain, allowing for better acceleration and highway cruising capabilities. Typically these kits are designed as "bolt-on" upgrades, meaning they can be installed without needing extensive machining or engine rebalancing, making the process relatively simple and straightforward. Compared to a complete engine rebuild, a Hooligan kit is a cost-effective way to significantly improve your bike's power. When installing a Hooligan kit, it may be necessary to upgrade the clutch to handle the increased torque produced by the larger engine. Depending on the specific kit and your bike setup, you may need to adjust fuel injection mapping to optimize performance.

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$1,128.95

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$1,822.95

S&S Cycle 1200cc to 1250cc Hooligan Cylinder Kits

Whether you are looking for better acceleration for everyday riding or more power for spirited driving, S&S Cycle 1200cc to 1250cc Hooligan cylinder kits provide a noticeable improvement. The larger displacement from 1200cc to 1250cc directly translates to more power, making the bike faster and more responsive, especially noticeable in acceleration and mid-range torque. These kits are designed to be "bolt-on" meaning they can be installed without needing to machine the engine cases or rebalance the crankshaft, making the upgrade process fairly straightforward. Each kit is tailored with the necessary components for your specific HD® model. Most Hooligan kits utilize the existing stock heads, pushrods, and fuel system, minimizing the need for additional parts or adjustments. Compared to a full engine rebuild or custom build, S&S Cycle's Hooligan kits are a relatively affordable way to significantly improve performance. Select the kit designed for your application needs.

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$1,822.95

S&S Cycle M8 132 in. Big Bore Kits

S&S Cycle M8 132 in. Big Bore kits are premium, bolt-on performance upgrades designed for 2017-current Harley-Davidson® Milwaukee-Eight 114 and 117 cu. in. engines, increasing displacement to 132 cu. in. (2163cc). These kits feature 4.320 in. bore cylinders, typically producing appx. 11:1 compression, without requiring engine case machining. Key details: * Maximum displacement: Enables the largest possible displacement for M8 engines without needing to bore the stock crankcases * Bolt-on installation: Simplifies installation by retaining factory engine height, avoiding the need for engine removal * Performance focus: Designed to produce significant increases in horsepower and torque, often paired with high-lift cams and improved exhaust systems * High-quality components: Includes forged pistons, premium piston rings, and aluminum cylinders with cast iron liners for better durability * Finish options: Available in finishes that match stock engines, including black and granite, maintaining a "sleeper" look * Commonly included components -- 4.320 in. Big Bore cylinders -- Matched forged pistons and rings -- MLS (Multi-Layered Steel) head gaskets -- S&S precision lifters and Quickee pushrods -- Cam cover badge * These kits are often used to upgrade to a Stage IV-style performance level, providing a massive torque boost. They are well-regarded for making high-horsepower, reliable builds on pump gas, especially when paired with proper supporting mods like 2-1 exhaust systems.

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$1,643.95

S&S Cycle 129 in. Power Packages with Chain Drive Cam

S&S Cycle offers 129 in. power packages with chain drive cam for a variety of Harley-Davidson© street bikes from 2017 and up. These packages are the ideal combination of performance and savings designed to transform your engine from mild to wild. They combine S&S's biggest big bore cylinders with matched 550 cam/cam-plate/oil pump and everything else a high performance cam chest needs to make big, reliable horsepower. Transform your 107 in. into a 129 in. monster. Additional details: * Available with 129 in. Big Bore pistons/cylinders * 550 lift cam for the perfect combination of horsepower and torque * Works with stock crankcases * Powdercoat finish matched to factory * MLS (multi-layered steel) head gaskets * Includes tappets, tappet cuffs, and high lift springs * Includes 129 cam cover badge

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$3,359.95

S&S Cycle 128 in. Power Packages with Gear Drive Cam

S&S Cycle offers 128 in. power packages with gear drive cam for a variety of Harley-Davidson© street bikes from 2017 and up. Kit details include: BIG BORE KIT: * 4.250 in. bore * Forged pistons * 11.1:1 compression ratio OIL PUMP/CAM PLATE: * Precision-machined from billet aluminum * Passage plugs removable for servicing * Independent scavenge sections for flywheel cavity and cam chest * Debris screens in both scavenge pickups * Magnet in cam chest to help stop debris from entering oil pump * Increased flow capacity on both feed and scavenge side * Pressure relief valve is adjustable with unit installed in engine * Kits now include updated oil pump with groove for optional OEM oil seal PUSHRODS: * Quickee pushrods with chrome covers TAPPETS: * Hand-assembled to exacting tolerances * Reduced valvetrain noise from start-up to shut-down * Close tolerances for low leak-down rates * Fast pump-up and superior high-RPM performance TAPPET CUFFS: * Hard anodized black coating * Billet aluminum construction * Stronger than stock material eliminates distortion * Improve tappet stability in high lift and high RPM situations CAM: * S&S 550 cam—designed for big bore applications * Gear drive kits provide improved cam timing accuracy and eliminate stock chain tensioner * Gear drive kits include outer drive gears VALVE SPRINGS: * Work well with cams up to .605 lift * High performance conical single-wire spring * Includes top collars, keepers, and valve seals/bottom collars

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$3,427.95

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$3,460.95

S&S Cycle 128 in. Power Packages with Chain Drive Cam

S&S Cycle offers 128 in. power packages with chain drive cam for a variety of Harley-Davidson© street bikes from 2017 and up. Kit details include: BIG BORE KIT: * 4.250 in. bore * Forged pistons * 11.1:1 compression ratio OIL PUMP/CAM PLATE: * Precision-machined from billet aluminum * Passage plugs removable for servicing * Independent scavenge sections for flywheel cavity and cam chest * Debris screens in both scavenge pickups * Magnet in cam chest to help stop debris from entering oil pump * Increased flow capacity on both feed and scavenge side * Pressure relief valve is adjustable with unit installed in engine * Kits now include updated oil pump with groove for optional OEM oil seal PUSHRODS: * Quickee pushrods with chrome covers TAPPETS: * Hand-assembled to exacting tolerances * Reduced valvetrain noise from start-up to shut-down * Close tolerances for low leak-down rates * Fast pump-up and superior high-RPM performance TAPPET CUFFS: * Hard anodized black coating * Billet aluminum construction * Stronger than stock material eliminates distortion * Improve tappet stability in high lift and high RPM situations CAM: * S&S 550 cam—designed for big bore applications * Available in both chain drive and gear drive variations VALVE SPRINGS: * Work well with cams up to .605 lift * High performance conical single-wire spring * Includes top collars, keepers, and valve seals/bottom collars CAM CHAIN TENSIONER: * Precision-machined from billet aluminum * Thicker shoe for longer wear * Direct chain oiling * Larger piston for more consistent pressure * Tighter tolerances improve stability

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$3,265.95

S&S Cycle 96 in. Sidewinder Big Bore Stroker Kits

S&S Cycle offers 96 in. Sidewinder Big Bore Stroker kits for a variety of Harley-Davidson© street bikes from 1970 and up. They're an economical route to a larger displacement engine. These kits contain nearly everything needed to take a stock 80 in. Harley-Davidson© Evolution Big Twin engine up to 96 in. displacement. They include S&S 3-5/8 in. bore aluminum Sidewinder cylinders and forged pistons, a 4 5/8 in. stroke dynamically balanced S&S flywheel assembly, complete with S&S heavy-duty connecting rods and mainshafts, head gaskets, base gaskets, and exhaust gaskets. Stock cases will need to be bored out to 3 5/8 in. Cylinders are available in a natural, gloss black, or wrinkle black finish.

Not Yet Reviewed

$2,879.95

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$4,499.95

S&S Cycle 4 in. Sidewinder Big Bore Kits

Inspired by S&S Pro Stock drag race engines, S&S Cycle 4 in. Sidewinder big bore kits utilize a ductile cast iron liner wrapped in cast aluminum for optimum thermal conductivity and performance. These bolt-in kits do not require machining, re-balancing, or engine removal, and include just about everything you'll need to complete the installation. S&S Cycle 4 in. Sidewinder kits offer the biggest cylinder bore that can be installed in a stock crankcase without machining! Features: * Low-friction ductile cast iron liner * 10.5:1 compression * Bolts in with no machining, balancing, or splitting the crankcases * 88 in. engines are boosted to 100 in. * 96 in. and 103 in. engines are boosted to 110 in. * Complete kits include cylinders, pistons, gaskets, and instructions * Wrinkle black and silver cylinders that match stock finish

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$1,540.95

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

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

The S&S Cycle 124 in. power packages with chain 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 in terms of increased horsepower and torque, particularly noticeable in the mid-range and top-end of the rpm band, making for a more powerful and responsive riding experience, especially when paired with other performance upgrades like ported heads and high-flow exhaust systems. Many power packages allow for customization by choosing different cam profiles to tailor the power delivery to your riding style, whether you prioritize low-end torque or high-end horsepower. Most 124 in. power packages are designed as "bolt-on" kits, meaning they can be installed without requiring extensive engine machining, making the upgrade process relatively simple. Select the 124 in. power package kit with chain drive cam designed for your application.

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$2,915.99

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$3,265.95

S&S Cycle 88 in. Big Bore Kits

S&S Cycle's 88 in. big bore kits provide significant benefits by increasing the engine displacement, resulting in more power and torque, especially noticeable in the low to mid-range powerband, while generally maintaining the stock engine character and rideability; essentially giving the bike a stronger punch with increased acceleration without drastically altering its feel. The larger bore size allows for more air and fuel to be ingested per combustion cycle, leading to a noticeable boost in power output, particularly in the low and mid-range rpm bands. For riders who frequently haul loads, the increased torque can be beneficial for pulling heavier trailers or carrying extra cargo. Many 88 in. big bore kits are designed to work with mostly stock components, requiring minimal additional engine modifications for installation. Compared to other performance upgrades like high-lift cams or forced induction, a big bore kit is often considered a cost-effective way to significantly increase engine power. After installing a big bore kit, proper engine tuning with adjustments to the fuel injection or carburetor settings is crucial to optimize performance and ensure efficient combustion. Select the S&S Cycle big bore kit specifically designed for your HD® model and year.

Not Yet Reviewed

$1,544.95

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$1,995.95

S&S Cycle 117 in. Big Bore Kits

S&S Cycle 117 in. big bore kits are a popular choice for riders looking to upgrade their engine power without major modifications. Available for a variety of Harley-Davidson® motorcycles, each kit is tailored with the necessary components for your specific HD® model. Many kits come with a powdercoat finish that can match the stock engine look to maintain a clean aesthetic. Using one of S&S Cycle's big bore kits can provide significant benefits like a noticeable increase in horsepower and torque due to the larger engine displacement, relatively easy installation with minimal machine work required, a quality build with durable components, and a good balance of performance and reliability. For best performance, appropriate camshafts, performance air cleaner, performance exhaust and fuel system tuning are required. Although not mandatory, S&S Cycle recommends adding an oil cooler to bikes ridden in warmer climates. Select the S&S Cycle big bore kit designed for your application needs.

Not Yet Reviewed

$1,643.95

S&S Cycle 132 in. Power Packages with Chain Drive Cam

S&S Cycle offers 132 in. power packages with chain drive cam for a variety of Harley-Davidson© street bikes from 2017 and up. These packages are the ideal combination of performance and savings designed to transform your engine from mild to wild. They combine S&S's biggest big bore cylinders with matched 550 cam/cam-plate/oil pump and everything else a high performance cam chest needs to make big, reliable horsepower. Additional details: * Available with 132 in. Big Bore pistons/cylinders * 550 lift cam for the perfect combination of horsepower and torque * Works with stock crankcases * Powdercoat finish matched to factory * MLS (multi-layered steel) head gaskets * Includes tappets, tappet cuffs, and high lift springs * Includes 132 cam cover badge * 132 Power Pack: Stock heads, 550 cam, stealth AC, stock throttle body, S&S manifold, power tune duals, MK45 muffler * Recommended for closed course competition racing

Not Yet Reviewed

$3,359.95

S&S Cycle 1250cc Conversion Cylinder Kits

The S&S Cycle 1250cc conversion cylinder kits are suitable for a range of Harley-Davidson® models, including the Sportster, which can benefit significantly from the added power. These cylinder conversion kits provide a significant increase in engine power and torque compared to the stock engine, making the bike significantly faster with a more noticeable acceleration, especially on smaller models like the Sportster, while often being a relatively cost-effective upgrade that can be done without major engine modifications or requiring a complete engine rebuild. This is particularly beneficial for riders seeking more power without drastically changing their bike's character. Each kit is tailored with the necessary components for your specific bike model. Many 1250cc conversion kits are designed to be installed without requiring major engine modifications, making them a good option for DIY mechanics. In most cases, you can use your stock cylinder heads, cams, and other engine components with a 1250cc conversion kit. Select the kit designed specifically for your HD® model and engine to ensure proper fitment.

Not Yet Reviewed

$1,008.95

S&S Cycle 124 in. Hot Set-Up Cylinder Kits

S&S Cycle 124 in. (standard compression) Hot Set-Up cylinder kits package pistons and cylinders for use as replacements or as the basis for a new engine build. The pistons are a flat dome design, and the cylinders are machined with the stock bolt pattern intended for use in stock crankcases. Select the appropriate kit for your Big Twin. S&S cylinder and piston kit contents and notes: * S&S 4 1/8 in. bore cylinders -- Durable wrinkle black powdercoat finish * Forged flat domed pistons, rings, wrist pins * Head and base gaskets * Designed for 4 5/8 in. flywheels, resulting in 124 in. displacement * Cylinders can be used with stock or S&S cylinder heads with stock bolt pattern

Not Yet Reviewed

$1,643.95

S&S Cycle 93 in. Sidewinder Big Bore Stroker Kits

S&S Cycle offers 93 in. Sidewinder Big Bore Stroker kits for a variety of Harley-Davidson© street bikes from the 1970s and '80s. They're an economical route to a larger displacement engine. These kits contain nearly everything needed to take a stock 74 in. or 80 in. H-D© shovelhead engine up to 93 in. displacement. They include S&S 3 5/8 in. bore high tensile cast iron Sidewinder cylinders and forged pistons with wristpin and rings, a 4 1/2 in. stroke dynamically balanced S&S flywheel assembly, complete with S&S heavy-duty connecting rods and mainshafts, S&S stainless steel headbolts, base nut, S&S adjustable chromoly steel pushrods, head gaskets, base gaskets, exhaust gaskets, and an S&S heavy duty-top motor mount. Kits are available with 8.5:1 or 9.1:1 compression.

Not Yet Reviewed

$3,795.95

S&S Cycle T111 Cylinder Kits

S&S is one of the most trusted names within the community of riders who choose to re-work their bikes for more power. The S&S Cycle T111 cylinder kits are an exceptional choice for upgrading your Twin Cam powered bike, delivering an economical and efficient route to enhanced performance. These kits are intended for replacing the cylinders and pistons on early production S&S T111 engines for 1999-2006 Big Twins. The kits contain top-of-the-line components such as S&S 4 1/8 in. bore cylinders, forged pistons, rings, wrist pins, head and base gaskets. Pistons are flat topped design intended for use with S&S Super Stock cylinder heads. The cylinders are machined with the S&S bolt pattern and are intended for use in S&S crankcases used in early S&S T111 engines. Designed for 4 1/8 in. stroke flywheels, resulting in 111 in. displacement. Cylinder available in either a silver or a durable wrinkle black powdercoat finish. For best performance, appropriate camshafts, performance air cleaner, performance exhaust and fuel system tuning are required.

Not Yet Reviewed

$1,499.95

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$1,660.95

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 T124 Cylinder Kits

The T124 cylinder kits from S&S Cycle are an exceptional choice for riders who choose to re-work their bikes for more power. This 4 1/8 in. bore cylinder and piston kit replaces the cylinders and pistons on early production S&S T124 engines for 1999-2006 Big Twins. The T124 cylinder kits include top-of-the-line components: S&S 4 1/8 in. bore cylinders, forged pistons, rings, wrist pins, head and base gaskets. Pistons are flat topped design intended for use with S&S Super Stock cylinder heads. The cylinders are machined with the S&S bolt pattern and are intended for use in S&S crankcases used in early S&S T124 engines. Designed for 4 3/8 in. stroke flywheels, resulting in 124 in. displacement. For best performance expectations, appropriate camshafts, performance air cleaner, performance exhaust and fuel system tuning are required.

Not Yet Reviewed

$1,635.95