HARLEY-DAVIDSON FXST SOFTAIL STANDARD Engine Kits & Rotating Assemblies Engines & Components - In Stock Filter Options - Vendor In Stock Filter Options - Free Shipping on Orders Over $109 at Summit Racing

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

Not Yet Reviewed

$1,395.86

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

Not Yet Reviewed

$1,175.36

Summit Bucks

S&S Cycle 98 in. Big Bore Kits

S&S Cycle 98 in. big bore kits are a fantastic upgrade if your Harley® is just a bit tired. The thicker and beefier cylinders mean that the engine will run cooler and you'll love the forged pistons that come with the kits. These are the largest bores that can be fit in your stock engine case. The cylinder and piston kits make going to the max bore size easy. There is no machining required and stock engine height is maintained. These kits come with nearly everything needed to get the most out of the added cu. in. to your stock engine. You won't believe how much power these kits produce! Features and specifications: * Kit yields excellent results with stock cylinder heads * Easy installation—no need to bore or split existing cases, just swap the cylinders * Available in a choice of either black or silver powdercoat finish with polished fins * Increased fin area for better heat dissipation * Valve pocket recessed in S&S pistons are enlarged for oversize valves and higher lift cams

Not Yet Reviewed

$1,187.06

Summit Bucks

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

$1,381.46

S&S Cycle 96 in. Big Bore Cylinder Kits

S&S Cycle's 96 in. big bore cylinder kits for a Harley-Davidson® motorcycle provides significant benefits by increasing the engine displacement, leading to noticeable power gains, particularly in the low and mid-range torque, resulting in better acceleration and improved overall performance, especially for riders looking for a more powerful ride without drastically altering the engine character. The larger cylinder bore displaces more air, allowing for more fuel to be burned, generating more power throughout the powerband, especially noticeable during acceleration. Big bore kits tend to focus on increasing low and mid-range torque, which is beneficial for everyday riding and pulling heavy loads. With a larger cylinder volume, the engine can react quicker to throttle inputs, leading to a more responsive feel. Compared to other performance modifications, a big bore kit can be a relatively straightforward upgrade, often requiring minimal additional changes to the engine. One of these S&S Cycle 96 in. big bore kits can be a great starting point for further performance upgrades like camshaft changes, ported heads, and upgraded intake systems to maximize power gains.

Not Yet Reviewed

$1,366.95

S&S Cycle 124 in. Big Bore/Stroker Hot Set-Up Kits

The S&S Cycle 124 in. big bore/stroker Hot Set-Up kits transform a stock Harley-Davidson® engine into a 124 in. monster. It includes: 4 1/8 in. bore pistons; big bore cylinders finished in wrinkle black powdercoat; a dynamically balanced 4 5/8 in. stroke 3-piece flywheel assembly complete with heavy-duty connecting rods and integral mainshafts; 640 gear drive Easy Start camshafts; chromoly steel adjustable pushrods; premium tappets; and Super Stock 91cc cylinder heads. When installed, the kits yield a 124 in. engine with a compression ratio of 11:1. Although the engine is .960 in. taller than stock, there are no frame clearance problems—and a stock EFI throttle body will fit, because the manifold mounting surfaces of the heads have been specially machined to fit a stock length manifold. If you ride a 2006 HD Dyna model, or a balanced or non-balanced Big Twin from 2007-17, these top-end engine rebuild kits are for you. Note: No fuel or ignition system is included. However, for the best results, a larger EFI throttle body, performance intake, and performance exhaust are recommended. The EFI system must be recalibrated. Although not mandatory, S&S recommends adding an oil cooler to bikes ridden in warmer climates. S&S does not recommend compression ratios higher than 10:1 for Tri Glide or other 3-wheel models (including conversions) due to extra loads caused by the lugging nature of these bikes. Detonation and subsequent engine damage may result.

Not Yet Reviewed

$5,636.66