Piston’s skirt is coated with molybdenum disulfide, which reduces the piston slap noise and thus the entire operating noise.
Molybdenum disulfide (MoS2)
The molybdenum disulfide (1) serves as a solid lubricant, like a Graphite or Teflon. This material helps resist metal wears even with little lube oil.
(1) Molybdenum Disulfide
HALF-FLOATING HEAD COVER
The rubber packing (2) is fitted in to maintain the cylinder head cover (1) 0.5 mm or so off the cylinder head. This arrangement helps reduce noise coming from the cylinder head.
(1) Cylinder Head Cover
(2) Rubber Packing