The history of the V-Twin really begins in 1904 with a 400cc single-cylinder, later in 1909 by grafting a second cylinder on a single block of Twin 825cc "F-head": The V-TWIN HD was born! Subsequently, the F-head evolve in power and reliability I ntil 1929, year of release of Flathead side valve, the famous "Laté" in french.

Flathead, Knucklehead, Panhead, Shovelhead, many engines that made ​​the myth of Harley-Davidson. More recently the Evolution and the Twin-Cam 88ci and 96CI in 2006. I pass rapidly over the Revolution (a 60 ° V-twin liquid cooled) which breaks the myth for me.

The V-Twin engine is historically at 45 º, with valves operated by pushrods, rocker arms and rods. Its particularity is to have a single pin crankshaft, connecting rods or both are linked in a special way, with a forked rod, and another classic, which allows cylinders to be online.
This adjustment to 45 ° with a single crankpin implies a non-scheduled operation, because the firing order is not made at equal intervals. The operating principle is as follows: With starting point in the cylinder top dead AV (explosion), reaching the top dead center of the cylinder AR (also explosion) must be (360 ° -45 °) = 315 °, Now to again reach the top dead center (explosion) of the cylinder AV, must (45 ° 360 °) = 405 °; A "gap" of 90 °, here is the secret of his famous Harley, a non-symmetrical wedge which generates the "Po-Po-tato tato" characteristic, but also generates a vibration of the engine and the bike, also legendary.



F-head model 7D -1911

The first engine was mounted on the " Silent Grey "A single-cylinder intake valve and has no automatic gearbox. In 1908 a second cylinder is grafted to 45 ° on the mono; This is the first V-Twin line, an original power of 7cv it will provide in its final version of 1929, 50hp to 5000trs/mn.


Flat head (flat heads) called Side or "lateral" at home, was produced for 43 years, from 1929 to 1972, a record of life in the history of motorcycling.

There are three cylinder capacity:
45ci = 750cc: 1200cc = 74c: 80CI = 1340cc



Knucklehead was released in 1936 with the EL model , The valves are but tumbled over the side of a cylinder capacity of 1000cc or 61ci power is 40hp.


He goes to 1200cc (74CI) and 45CV in 1941.
For purists, this model remains one of the better side.


Big change in 1948 with Panhead and aluminum cylinder heads, hydraulic tappets and its new rocker. With an output of 50 hp from a displacement of 1000cc, this engine has evolved considerably in its time.
It will equip in its 1200cc 55 hp of output in 1953, the first electra-glide in 1965


The transition engine Panshovel adopts new cylinder heads and rocker covers, his last office are now also supporting rockers, thanks to a clever molding and two-axis supporting the rocker, This mounting-lubrication distribution, weakness of the former assembly Panhead. The shape of these media will give him the name Shovelhead (shovel head). The engine remains below that of a Panhead from the onset until the end of 1969 a new low-engine. This engine is paradoxically with 66 hp (FLH) more powerful than the future range Shovel.


In 1970 the "Pan-shovel" disappears after changing the lower engine which now includes the generator smaller than the generator. A plateau ignition breaker points is placed in the new timing cover cone-shaped, remains to 1200cc engine capacity, it was not until 1978 that the shovel pass to 1340cc (80CI) and 65hp, he finished his career in 1983 with the arrival of Blockhead.

Evolution ou Blockhead

This time it's an all-aluminum engine that reveals the firm in 1984, the study in partnership with Porsche does not stray from the Shovel, which incorporates the features, a displacement of 1340cc, alésageXcourse are identical: 88, 9mmX107, 95mm.

This engine due to its reliability will allow the firm to re-gilded his image well into the production quality of AMF years. Sold over a million copies during the fifteen years of manufacturing, the Evolution V ² foreshadows today's engines


Twin-Cam 88 et 96

1999With the advent of anti-pollution standards more stringent, the Evo has to leave the hand at the Twin-Cam 88, Twin-Cam for his two camshafts, 88 for its displacement of 88ci (1450cc). It is dopted of electronic fuel injection, and is air cooled.
Version B in 2000 the team internal balance shafts that absorb vibrations.
The 2007 vintage Twin Cam 96 has a displacement of 1584cc, compared to the 1450cc Twin Cam 88 it replaces. the piston stroke increased from 101.6 mm to 111.1 mm, the bore does not change (95.3mm) Version B, as his little brother is designed to be mounted rigidly on all softail models .


Revolution for the Millennium (2001) the Harley-Davidson engines to the kitchen "Japanese sauce"!

Revolution because it goes into cooling liquid.

Revolution because its timing is 60 ° rather than 45 °

a displacement of 1131cc it develops 115 to 120 hp depending on the variations of the range V-ROD

V-Twin in action (thank you Todd8080)

Sportster Ironhead (1957-85)

In the V-Twin should also mention the Sportster, engine-box sets that appeared in 1952 with a series k the Flathead. The first true Sportster engines successor to the series K, are introduced to counter the Triumph and other Englishwomen, who invade the United States. XL baptized they exist since 1957, 45ci (750cc) in 1952 and then 54ci (900cc) in 54 moves in a 1000cc (61ci) in 1972, in 1977 he coveted team cafe-racer He finished his career in 1985.

Sportster Evolution

As the Big Twin, Sportster 1986 version goes "EVOLUTION" all aluminum. Engine sizes available are 883cc and 1100cc: 1200cc replaced by one of 67cv in 1988. In box 91 from 4 to 5 speed. But this is the version of 1996 Evo II that brings 1200s new cylinder heads and camshafts, a larger carbs, and here is the twin generous and more torque in the midrange.

Design by Bloom