Developed and produced drawing on the state of the art
Motorservice always supplies pistons complete with piston rings, piston pins and the associated piston pin circlips. These expertly coordinated components make ordering easier for you.
Aluminium pistons are light and have ideal thermal conductivity properties. They feature integral reinforcement parts, such as cast iron ring carriers, steel parts for defined thermal expansion or ceramic fibre reinforcements of aluminium oxide, depending on the intended application.
Articulated pistons are used in the construction of utility vehicle diesel engines when conditions are too harsh for aluminium pistons. They consist of a steel upper section and an aluminium piston skirt. Both these parts are connected with friction-locking by the piston pin. Compared with aluminium pistons, articulated pistons boast higher strength in the steel upper section. This makes them more resistant to high pressures and temperatures.
Steel pistons (monobloc)
Steel pistons are forged from highly heat-resistant steel with high stress endurance. They withstand high ignition pressures, even at maximum temperatures. They are therefore used in heavy-duty diesel engines in utility vehicles and passenger cars, where they ensure maximum service life and superior reliability. Working in co-operation with various American and European engine manufacturers, Kolbenschmidt has successfully developed steel pistons for utility vehicles and passenger cars in recent years.
These aluminium pistons are used in piston compressors to generate compressed air in utility vehicles. They are subject to a lower thermal load than engine pistons, as they are not exposed to combustion.
Whether it's special coatings such as LofriKS®, NanofriKS® or graphite coatings or special piston pin bores (Hi-SpeKS®) to increase wear resistance and durability – Kolbenschmidt is a leader in cutting-edge technology for piston development.
Technical names and names on the piston
|1 Ø bowl|
|2 Piston crown|
|3 Combustion chamber (bowl)|
|4 Piston crown edge|
|5 Piston top land|
|6 Compression ring groove|
|7 Ring land|
|8 Groove base|
|9 Recessed ring land|
|10 Groove sides|
|11 Oil scraper ring groove|
|12 Oil return bore|
|13 Piston pin boss|
|14 Retention for groove distance|
|15 Groove for retainer ring|
|16 Piston boss distance|
|17 Piston boss distance|
|18 Stepped edge|
|19 Piston diameter 90 °C against the piston pin bore|
|20 Piston pin bore|
|21 Bowl depth|
|23 Ring zone|
|24 Piston compression height|
|25 Piston length|
|26 Oil cooler duct|
|27 Ring carrier|
|28 Bolt bush|
|29 Ø measuring window|
|30 Crown camber|
Gap Dimension and Top Dead Centre
The gap dimension (B) is the protrusion or recess of the piston in the top dead centre in relation to the sealing face of the cylinder block. The thickness of the cylinder head gasket and a possible recess in the cylinder head are taken into account for measuring. This dimension is also known as “lead dimension”.
Piston protrusion or piston recess dimension in top dead centre for different engine versions
Below the dimension C, the protrusion (marked by + ) or the recess (marked by - ) of the piston in the top dead centre is to be understood in relation to the cylinder block sealing face. The seal thickness or geometrical shapes of the cylinder head are not taken into account.
For engines with wet cylinder liner, the protrusion or recess of the piston is also measured in relation to the cylinder block face. A protrusion of the cylinder liner or an existing land edge is not taken into account.
For air-cooled cylinders, dimension C refers to the distance between piston crown and the seat of the cylinder head on the air cooled cylinder.
For setting the piston protrusion, pistons with reduced compression height are also available in addition to the standard pistons.
For pistons the crown for setting the piston protrusion must not be turned off.