1909-1911

Harleys first v-twin

45-degree 49.5 cubic w/ 7hp

1911-1929

F-head

1929-1936

Flathead

The Flathead was named because of the telltale flat vented tops that are recognizable at the top of each cylinder head.

45cu

The engine proves to be so reliable that variations of it are available on Harley-Davidson motorcycles as late as 1973.

(pictured is a 45" "R" 1932-36)

1936-1947

knucklehead

On the eve of WW2, Harley-Davidson® introduced an overhead- valve V-twin® with "knuckly" covers on the valves.

Overhead valve EL-61cu 40hp

Side valve-80cu

1948-1965

Panhead

New features are added to the 61 and 74 overhead valve engines, including aluminum heads and hydraulic valve lifters that supplied oil through rocker arms, the panhead hit the market in 1948, named for the pan-like cover where the knuckles used to be.

1956

KHK K-Series

1952-53 K 45" 750cc.
1956-56 KH 54" 885cc

1957

The motorcycling public met a new motorcycle called the Sportster®. It premiers as a 55 cubic inch overhead valve engine.

1966-1985

Shovelhead

By 1966 the Panhead underwent still more improvements, the most noticeable being the distinctive enclosed cylinder head in a sleek, slightly curved top. At a glance this looks unmistakably like a shovel with the pushrods resembling the handle of a shovel, and the head, the shovel itself.

1984-1999

Evolution

In 1984 on the heels of a bold employee buyout of AMF, The motor company went public and introduced it's now famous redesign of the v-twin. This radical new design utilized styled square blocks to house the valves.

4-Cycle, 45 Degree V-Type, 1340cc, 80cu compression: 8.5:1, Oil-bath diaphragm clutch and electronic ignition.

1986

The Sportster® motorcycle line receives the Evolution V-twin engine.

1986 - 883cc & 1100cc

1988 - 883cc & 1200cc

2000-2006

Twin Cam 88

With numerous American motorcycle manufacturers trying to surface and re-surface Harley-Davidson introduces it's most revolutionary engine yet. The Twin Cam 88TM gets its name from its two cams.

B= Balanced

1450cc

2001-Present

Revolution

Liquid-cooled, 1130cc, 115 horsepower. The Revolution engine's basic configuration is a 60° V-Twin with dual overhead cams and four-valve heads. It's a high-revving design, with a 9000 rpm redline. Two velocity stacks housed in a massive air box allows it to breathe aggressively. Electronic fuel injection system, modified for high performance, and a new high-energy plug-top ignition coils.

2007-Present

Twin Cam 96

Compression 9:2:1

EFI