Piston And Piston Ring; Oil Pan - wsm wg972-e4 Workshop Manual

WG972-E4, WSM

[5] PISTON AND PISTON RING

[6] OIL PAN

Piston and Piston Ring
The piston head has the combustion chamber (1)
with the concave of bathtub shaped type.
Top Ring:
Barrel-faced type has an ideal shape in terms of
lubrication theory in order to prevent abnormal wear due
to edge loading at the time of initial running-in, and it is
very effective in prevention of blow-by.
Second Ring:
In this type, undercut machining is interrupted at both
ends of the joint. It has an oil scraping property which is
inherent to the scraper type as well as control action
against blow-by which is caused by undercutting.
Oil Ring:
Oil ring consists of three steel components, that is
upper and lower rails and one spacer being held
between two rails. This function is particularly effective in
preventing oil-up because of high boost at the time of
engine coasting.
(1) Combustion Chamber
(2) Top Ring
Piston Skirt
Piston's skirt
disulfide, which reduces the piston slap noise and
thus the entire operating noise.
 Molybdenum disulfide (MoS
The molybdenum disulfide serves as a solid
lubricant, like a Graphite or Teflon. This material helps
resist metal wears even with little lube oil.
(1) Molybdenum Disulfide
The oil pan is expanded under the gear case.
Therefore, the height of the engine can be lowered more
than so far while securing a necessary amount of oil.
(1) Crank Case
(2) Oil Pan
1-M3
(3) Second Ring
(4) Oil Ring
9Y1211108ENM0006US0
is coated with molybdenum
)
2
9Y1211108ENM0007US0
(3) Gear Case
9Y1211108ENM0008US0
KiSC issued 07, 2015 A
ENGINE