American Motorcycle Dealer AMD 244 November 2019 | Page 54

Wiseco Tracker Series H-D Big Bore Pistons
iseco says that its new Tracker
Series pistons have been
created "to provide a featured,
high-performance forged piston
option at a more affordable price that is
available in various overbore and
compression ratio options."
Development on the new Tracker Series began at the
end of 2017, with manufacturing having kicked off
around April this year. "The hurdle was to find a
balance between performance and price - our
engineers have succeeded by blending classic piston
manufacturing processes with state-of-the-art
techniques."
W
Near-Net Shape Forging
"The major challenge in this project was to decrease
the end cost to the consumer. That's where near-net
shape forging came into play," says Wiseco engineer
Dave Sulecki.
"Near-net shape forging is where we form most of
the geometry on the top of the piston - it is built-in
at the forging process. The crown and the valve
pockets are forged into the part. Those areas are
machined in most other piston manufacturing
processes.
"You forge out the aluminum and get the slug, then
you have to machine all of that metal away to get
the valve pockets and the crown to achieve whatever
specific design you're trying to hit, or the specific
compression ratio you are looking for. At Wiseco we
are forging those features directly into the piston.
When our near-net forged pistons come off the
presses they need less finishing and machining as
they go through the factory. The whole crown area
comes right off the press and looks like a finished
product. It's a really unique way to form a piston."
Sulecki says that upon inspection, "it doesn't take a
metallurgist to realize that different processes were
utilized during construction of a Tracker Series piston.
The mirror-like sheen of the machined area is offset
by the textured surface of the forged aluminum left
during near-net shape forging. Those visual
differences are also noticeable on the underside of
the piston.
Aligned Grain Flow
"One of the upsides to near-net shape forging is that
it gives the piston added strength, since the features
are being forged in. This process allows the
PARTS AND ACCESSORIES
Wiseco offers fully featured high-performance pistons, such as the Black Edition line, but found it was
missing a featured performance piston at a mid-level price point. The new Tracker Series piston line is
engineered to fill that gap - "a featured, high-performance piston offering for Evo, Twin Cam and
Sportsters at a more affordable price point."
The forgings for Tracker Series pistons have crown features designed into them - so when the piston is
forged, valve pockets and any other crown designs are already complete, requiring no additional
machining.
The valve pockets show a forged aluminum finish because they required no machining. Other features,
such as the oil drain backs, are also forged into the part instead of machined, to keep the cost down.
aluminum to flow through the features of the piston
with an aligned grain flow. That grain flow condenses
the aluminum for better fatigue strength and overall
durability.
"The other upside, of course, is the cost compared to
the combined forging and machining needed for
piston ranges like our Black Edition series and
ArmorPlating featured pistons. Those cost savings
trickle directly down to the consumer - a Tracker
Series piston is roughly $80-$100 (at retail value)
less than the higher price point offerings."
to reducing friction and is applied to the skirt, and
we take it a step further by emblazoning our logo
Feature-Rich
Wiseco says that "as with all our pistons, the
forging process aligns the grain structure of the
aluminum to provide improved tensile strength.
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Aside from outstanding durability and a very
attractive price point, Wiseco says that the Tracker
Series piston "has a secret weapon in the
performance department. ArmorGlide is our solution
AMERICAN MOTORCYCLE DEALER - NOVEMBER 2019
ArmorGlide skirt coating is a proprietary dry-film
lubricant designed to reduce friction and
operation noise for the life of the piston.
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