American muscle.
Bolt‑in power.
Since 1958.
Engines, big bore kits, cams, carbs and exhaust from the company that's been building V-twin horsepower in Viola, Wisconsin for more than 65 years.
Shop by category
Every listing names its engine platform and model years right in the title — pick the category, then match it to your motor.
Build a combo, not a parts pile
S&S designs its cylinders, cams and exhaust to work together, so you can pick a proven combination instead of guessing which cam goes with which bore.
More cubes. Same bike.
Power Packages and big bore kits take a stock M8 or Twin Cam to 124", 128", 129" and beyond — cylinders, pistons and cams sized to work together.
Shop big bore kits →
Drop in a whole motor
T124 and T143 long blocks, engine cases and Super Stock® bottom ends for builds that start from the crankcase up.
Shop engines →
Let it breathe. Let it bark.
Grand National slip-ons, Swindler 2-into-1 conversions and Qualifier systems for Harley-Davidson and Indian — 50-state and race-only options.
Shop exhaust →Genuine S&S Cycle
Every part on this page is real S&S — the same engine components builders have trusted since 1958. No look-alikes, no knock-offs.
Fitment in the title
Each listing names its platform and years — M8, Twin Cam, Evo, Sportster, Shovelhead or Indian — so you can see what fits before you click.
Build it complete
Big bore and cam upgrades usually need gaskets, pushrods and a tune. Tell us your combo and we'll help round out the parts list.
Questions before you buy
Not sure which cam or bore size suits your riding? Email Support@lifestylecycles.com and a human answers.
Your motor. More power. No guesswork.
Start with your engine platform, then pick the part. If you're not sure something fits your year and model, ask — we'll check it before you order.