The piston pin is offset 0.3 degrees from the centerline to reduce 'piston slap
' against the cylinder wall, minimizing NVH
et al., "A Numerical Model of Piston Secondary Motion and Piston Slap
in Partially Flooded Elastohydrodynamic Skirt Lubrication," SAE Technical Paper 940696, 1994, doi:10.4271/940696.
Mechanical noise mainly includes piston slap
noise, air valve knock noise, gear meshing noise, and fuel injection pump noise.
Instead of it being located on a crank, the clever design means that the piston slides absolutely vertically on a geared rail so that piston slap
The pistons have an offset piston pin and extended piston skirt that reduces piston slap
and thus engine noise levels, Sugar said.
It is used to take out the piston slap
when placing in new rings.
This causes the piston to shift in the opposite cylinder wall just before top dead center greatly reducing piston slap
When mechanics say: "That noise could be a rod or main knock, piston slap
, or a bad lifter."
"Among the signals coming from the cylinder are those that result from piston slap
, which occurs in an engine because of the changing angle of the crankshaft as it revolves through a full stroke," Lyon said.
This causes the piston to shift to the opposite cylinder wall just before top dead center, greatly reducing piston slap
This has also reduced engine noise, since closer tolerances yield less piston slap
at low load and cold start conditions.
has been reduced by optimizing the clearances between the single-piece piston and the cylinder and the piston skirt features a molybdenum coating that improves fit within the cylinder.