About The V-Twin
Engine
If
you are a chopper lover then you are
probably familiar with the v-twin
engine. Do you know why the V Twin
is named a V Twin?
The V
Twin engine is a two-cylinder engine
layout in which the cylinders form a
"V". The V-Twin engine's
pistons are aligned so that, if
viewed along the line of the
crankshaft, they appear to be in a
V.
The V
configuration reduces the overall
engine length and weight compared to
an equivalent straight engine (the
straight engine or in-line engine is
an internal-combustion engine with
all cylinders aligned in one row.)
The
v-twin configuration allows for
optimum torque for a given
displacement...POWER.
V
twin engines can be mounted in the
transversal position (the definition
of 'transversal' is a line extending
or lying across at right angles to
the long axis.)
V
twins on Harley Davidson Motorcycles
are mounted in a parallel position.
The
longitudinal V Twin (the definition
of longitudinal is: lengthways,
lengthwise) as seen on Moto-Guzzis
and some Hondas is less common. This
position is well adapted to its
transmission shafting, but has the
disadvantage of causing a torque
reaction that tends to lean the
motorcycle on the side.
The
first V Twin was introduced in 1903,
updated with two and three-speed
gearboxes.
The
Indian was one of the first US
makers to offer a successful V Twin
in 1907.
The
most obvious configuration for a V
Twin is a 90° angle, but other
angles can be achieved like the 45°
Harley-Davidson.
Here's how a V Twin engine
works...
A
normal two cylinder engine fires the
pistons in such a way that one fires
on the first revolution of the
crankshaft, and the second one first
on the second revolution.
The
engines runs quite smooth under this
design.
But
a Harley engine has two pistons, and
the crankshaft has only one pin (in
the design above, which is a common
design, there are two crank pins for
the connecting rods which the
pistons connect to), and both
pistons are connected to it.
So
the pistons fire almost at the same
time. Whereas in the example above
they fire at different intervals.
This
gives the choppers, and most
particularly the Harley Davidson
V-twin its unique sound, throaty, in
your gut...you know what I mean...
This
vtwin motorcycle is one of the early
versions at 90 degrees...
As
you probably know, the first
choppers to come out with this
engine were the Harleys, so we can
easily say that the v-twin engine
was born in the Harley Davidson's
factories.
The
Harley V Twin is generally credited
to Bill Harley, who designed it in
1908 as H-D's Chief Engineer. He
went to work on the design right
after graduating from the University
of Wisconsin in 1908. Those first
Harley V-twin engines proved to be a
failure. In 1910, the V-twin
engine dropped from Harley
Davidson's line.
But
it was soon re-designed and appeared
again in 1911.
V-tiwn's
are not just for Harley's and
Indian's. Many manufacturers use the
configuration on their bikes:
Suzuki, Kawasaki, Yamaha,
Honda...all have V-twins.
