The Panhead
Engine
Here is some little known but
basic information on the panhead
chopper engine:
The pan-head
engine is Harley-Davidson's second
overhead-valve engine. This engine
was introduced in 1948. It was
quieter and cleaner than the
Knucklehead (another type of the
Harley Davidson engine) which had
been used since 1936.
The Knucklehead
was named after the
knuckle-like valve covers look
of an upside down cake pan on the
top of the engine.
The Pan head got
its name from the large flat
covers at the top of the
cylinder heads. It had a better
cooling system than the
Knucklehead, as well as other
modifications that reduced wear.
This made it easier to maintain.
Nonetheless, the
panhead didn't change much from
the knuckle. But it came equipped
with aluminum heads for more power
because the bikes were getting
heavier. Also, the heat beater was
depressed.
In 1955 Harley
modified the pan head engine by
installing a more efficient lower
end (this is why the panhead is
quieter than the knucklehead.)
Pan head engines
were also the first v-twin to come
with an electric starting system
in 1965.
About the
frames mounting these engines...
There are several
differences between the pan and
knucklehead frames, but most of
them are pretty hard to spot. Some
differences are infrequent, like
the straight front downtubes. The
knucklehead frames have straight
tubes’ while most of the rigid
pan head frames have
"bowleg" tubes.
However, the early
1948, late’56, and ’57 pan
frames were also straightbars. The
one sure way to tell the
difference is the top motor mount.
The top motormount on a knucklhead
frame is a straight-sided
rectangle tab, but the top mount
on a panhead is a triangular sort
of shape.
It's possible to
fit a pan head engine into a
knucklehead frame, but it takes
some serious grindnig and welding,
and some hammering.
It is quite well
known that a lot of bikers think
that the pan head choppers are the
most beautiful mechanical
masterpieces ever created by
mankind. One of the reasons for
this statement is it's better
and quieter engine. In fact,
the appearance of the pan head
chopper is not at all so different
that the one of the knucklehead
chopper.
You can even build
your own panhead chopper, as long
as you have the resources. If you
don't want to spend a lot of money
and time, you can simply buy the
panhead chopper you like. All you
have to do is to find the bike for
you and to go out for a ride. You
will surely fall in love with the
pan head chopper; no matter if it
is a Harley or any other pan head
bike.
