Harley Davidson Engine Buying Guide

By Published by
. Views . Comments Comment . 2 Votes
Harley Davidson Engine Buying Guide

The Harley Davidson brand of motorcycles is probably one of the most recognised names in the motorbike industry, and for good reason. The Harley Davidson line of motorcycles are an American classic which offer three types of motorcycles that include off-highway, street, and dual-purpose models. The engines used in all three lines are designed with high-quality parts which makes buying a Harley Davidson engine worth the initial investment.

These engines are located at motorbike shops and online at eBay. There are many new, used, and refurbished engines to choose from, each which offers a variety of benefits to motorbike owners. Knowing more about these engines, such as the different engine types, assists riders in choosing the proper one for their bikes.

Types of Harley Davidson Engines

Complete Harley Davidson engines are categorised into five groups. Each group of engines is manufactured during different time periods, and includes a variety of models, head designs, cylinder designs, and case designs, as well as different carburettors, transmissions, and other various components. Each engine used in these groups is available within various lines and models of motorcycles manufactured by this company.

Knucklehead Engine

This engine is one that Harley Davidson manufactured between the years 1936 and 1947. These engines are ones used on lines that include the OHV EL, UL, WL, FL, WLA Army, and XA 750 cc Army models. The head design on the Knucklehead engine varies from that of the flat engine, as it has exhaust and intake valves on the top of the combustion chamber, vs. the valves being on opposite ends of the chamber.

The cylinder design is one that is constructed from cast iron and includes a case design that uses a centrifugal bypass oil pump which replaced the recirculating dry sump oiling system of older models. With that upgrade came the upgrade of the carburettor to the Linkert models. Other upgrades for this engine also included a four-speed version with optional gearing for sidecars, which replaced the three-speed model along with a three-speed and reverse model transmission.

Panhead Engine

The Panhead line of engines was manufactured between 1948 and 1965. They are installed on the models that include the FL Pan, Hydra Glide, K, KH, XL Sportster, FL Duo Glide, and FL Electra Glide motorcycles. The head design is the same as the Knucklehead model with the exception that the Panhead engine also includes noise suppressors, valve oilers, and aluminium heads.

The cylinder design is cast iron with the top of the cylinder featuring an inbuilt fire ring. The case design of new models includes crankcases that received revisions along with electric starters. This engine uses a Linkert carburettor with E and F transmission models and also includes four-speed or foot-shifting abilities.

Shovelhead Engine

The Harley Davidson Shovelhead engine is one that was manufactured between 1966 and 1985. The most current Shovelhead engines are installed on the Classic, Fat Bob, Wide Glide, Tour Glide, Low Rider, and Sportster models, just to name a few. The cylinder design is one which is constructed of cast iron that includes an inbuilt fire ring on the cylinder top. The alternator replaced the generator with this case design later being changed over to one of a rubber-mounted engine.

The different carburettors which are used in the Shovelhead engine include the Bendix, Tillotson, and Keihin butterfly versions. Newer models either include the five-speed transmission in a four-speed transmission case compared to the four-speed plate top or four-speed ratchet top transmission designed for earlier models.

Evolution Engine

Manufactured during between the years 1984 and 1999, the Evolution engine is used on a wide variety of Harley Davidson motorcycles that include the Fat Boy, Dyna Glide, Daytona Dyna Glide, Super Glide, and Low Rider models. The aluminium heads are designed to minimise oil leaks and also includes flat pistons along with side-squish combustion chambers. Aluminium cylinders are incorporated in the engine created with a head bolt pass through design. Improvements are made to the case with a lower end design also being added. The Evolution engine includes EFI carburettors which changed over to Keihin ones later while still using the same carburettor found in the later Shovelhead models and newer versions of the transmission that features a five speed drum shifter.

Twin Cam 88 Engine

The Twin Cam 88 engine began being manufactured in 1999. All Dyna and Touring models manufactured since 1999 include the Twin Cam 88 engine with the Sportster following a couple of years later. This engine features an aluminium head with a bathtub combustion chamber of 88 cc. The cylinder fin design is doubled for cooling and the O-ring replaces the paper gasket on the case design. EFI or Keihin carburettors are used with a newer shifter design in the transmission.

Engine Comparison

Each engine varies in capabilities - particularly if it is custom or refurbished. At the end of the day, thee engine makes a Harley a Harley Davidson.

Engine Type

Relative Cost

Knucklehead Engine


Panhead Engine


Shovelhead Engine


Evolution Engine


Twin Cam 88 Engine


Harley Davidson bikes do not have to be a costly investment, but for the true admirer, cost is of no issue.

Harley Davidson Motorcycle Lines

Harley Davidson manufactures several different lines of motorcycles and many references to engines are made by notating the line and model of motorcycle. The Dyna line features a variety of engines to choose from that include ones built for the Wide Glide, Fat Bob, Street Bob, Super Glide Custom, and Switchback models. The Softail line includes engines for the Breakout, Fat Boy Lo, Heritage Softail Classic, Fat Boy, Softail Deluxe, and Softail Slim models. The Sportster line includes engines for the Iron 883, SuperLow, 1200 Custom, Seventy-Two, and Forty-Eight models.

The Touring line includes engines for the Ultra Limited, Road King, Street Glide, Electra Glide Ultra Classic, and the Street Glide Special models. The VRSC line of engines includes any designed for V-Rod Muscle or the Night Rod Special models. The Trike line of engines is built specifically for the Tri-Glide Ultra model. Becoming familiar with these various Harley Davidson motorcycles lines make the job of locating the right engine easier.

How to Buy a Harley Davidson Engine on eBay

When it comes to finding the right engine for your Harley Davidson, there is no easier way to find it than on eBay. There are a variety of models to choose from which can be located by entering descriptive keywords into the search query box on any eBay web page. Take note of which individuals are ranked as Top-rated sellers, since these are the sellers who have proven track records of great customer service.

Knowing more about the various types of Harley Davidson engines and their specifications is helpful for finding great deals on engines within certain product lines. Engine designs change over time and often it is hard to be able to keep up with all the upgrades for each type. Being able to review engine specifications before buying a Harley Davidson engine ensures that consumers are getting what they expect.

Write a guide
Explore More
Choose a template

Additional site navigation