Complete Engines
About Complete Engines
A complete engine replaces the whole motor in one step. Riders look here when the original engine has failed beyond a sensible repair, when they are building a custom bike, or when they want a different engine character without assembling it part by part. The current listings are all long block engines from S&S Cycle for Harley-Davidson models.
A long block is an assembled engine, with the crankcase, rotating assembly, cylinders and heads in place. It does not normally include every bolt-on part, such as the intake, exhaust and ignition, so read each listing for what comes with it. The names show the family the engine suits, such as Touring and Dyna, M8 Softail, Big Twin in a custom chassis or Evolution Big Twin in a custom frame. Check the primary drive, the frame mounts and the transmission, since these must be compatible. Some listings are marked Race Only or 49 State, so read those notes and check your local emissions and registration rules before ordering. A new engine usually needs tuning, and a professional installation is a good idea.
The brand in this category is S&S Cycle. If you are rebuilding instead, see Engine Rebuild Kits & Components, Complete Cylinders and Crankshafts. Engine Mounts are listed separately. All are in Engines & Engine Parts. For your model, pick your machine in the Ride Finder at the top of the page.
FAQs on complete motorcycle engines
What is a long block engine?
A long block is an assembled engine that includes the crankcase, crankshaft, pistons, cylinders and heads, and usually the valvetrain. It normally leaves off items such as the intake, exhaust and ignition. Each listing describes what is included, so read it before you order.
Will a complete engine bolt into my existing frame?
Only if it is made for that frame and drivetrain. Check the engine family named in the listing, such as Touring, Dyna or M8 Softail, and the notes about primary drive and mounting. If the bike is a custom build, confirm each connection point before you order.
Do I need to tune the bike after installing a new engine?
Usually yes. A different engine can need a different fuel map or carburetor setup and ignition settings, and the maker's instructions say what is required. Have the bike tuned on a dyno or by a qualified shop for safe and smooth running.
What does Race Only or 49 State mean on an engine listing?
These notes describe where the engine is intended to be used. Race Only means not for street use, and 49 State means it is not made for California emissions rules. Check your local requirements and the product notes before buying.
Is a complete engine better than rebuilding my old one?
It depends on the condition of the old engine and the work involved. A complete engine saves assembly time and comes ready to install. A rebuild can cost less when only some parts are worn. Compare the cost and what each option includes.
