HEAVY DUTY PARTS

4
Pistons - Aluminum
The demands placed on aluminum pistons for
commercial vehicles have been continuously
tightened over the years. Higher performance
requirements trigger increased thermal loads.
Furthermore, brake mean effective pressures
(BMEP) and peak pressures are rising.
MAHLE Clevite offers years of experience and
innovative solutions, continuously adjusting
the existing product range to tomorrow’s
requirements.
The Clevite Aluminum Piston Program
The piston range for heavy duty engines
includes optimized aluminum pistons for
highest demands. The pistons are made of
cast, high temperature-resistant aluminumsilicon
alloys. These alloys and the fine-tuned
casting technology make it possible for
Clevite ® pistons to ideally combine low weight
and high structural rigidity. The products
withstand peak cylinder pressures of more
than 2,900-psi. If properly combined with
other components, they ensure a service life
of more than 600,000 miles for commercial
vehicles.
Aluminum Pistons Under Load –
Optimized for Every Requirement
Depending on the thermal and mechanical
requirements, aluminum pistons for heavy
duty applications excel based on the following
characteristics:
QQ Optimized alloy
QQ Optimized casting process
QQ Spray jet cooling
QQ Ring carrier
QQ Salt core cooling channel
QQ Elevated salt core cooling channel
QQ Cooled ring carrier
QQ Bowl rim reinforcement
QQ Pin bore bushing
Clevite ® pistons for commercial vehicle diesel
engines are cast from high temperatureresistant
aluminum alloys. Standard features
are:
QQ Ring carriers made of high-strength,
austenitic cast-iron (Ni-resist) for improved
wear resistance of the first ring groove
QQ Salt core cooling channels or cooled
ring carriers and GRAFAL ® coatings for
optimization of skirt running behavior
For high-performance engines, bushings in
the piston pin bores are used.
Local Reinforcements for Maximum
Strength
In addition to measures such as the casting
in of ring carriers and the insertion of pin bore
bushings, aluminum oxide fibers are infiltrated
as well, to reinforce the thermally stressed
combustion chamber bowl.
Cooled Ring Carriers for Critical Areas
The cooled ring carrier allows for significant
improvement of piston cooling in the critical
areas – bowl rim and first ring groove. The
cooled ring carrier consists of a Ni-resist ring
carrier, to which a thin austenitic steel sheet
with intake and outlet openings is welded. This
combined insert – cast into the piston – brings
the heat transfer to the cooling oil even closer
to the combustion chamber and the first ring
groove. Critical areas are thus cooled much
more effectively than using salt core cooling
channels.