f
ENGINE
CYLINDER HEAD ASSEMBLY
Cylinder
head
The head, made
of
a special cast iron,
is
shaped
to
retain greater rigidity and
promote
the conduction
of
excess
heat
to the coolant.
As
will be
noted
in the cross section, the head
carries overhead valves arranged for cross-flow
intake-air admission and scavenging,
with
intake
port
located
on
the right and
exhaust
port
on
the left. The high power capability
of
the Model
K3A and K3C
is
measurably
accounted
for the
improved volumetric efficiency resulting from
this valve configuration.
The pre-chamber (pre-combustion chamber),
in which the swirl
type
of
pre-combustion takes
place,
is
of
insert type in construction, and
is
press-fitted into the cylinder head
to
form its
integral part.
The
pre-chamber
is
not
meant to
be removed from the head in engine disassembly.
The valve guides for
both
intake and exhaust
valves are common, there being no need to
distinguish between the two.
They
are
of
a
sintered alloy, impregnated with oil for increased
resistance to abrasive wear.
2-4
2 3
l-Nozzle holder
2-Cylinder head
3-Mouth piece
4-Glow plug
5-Valve spring
6-
Valve stem
seal
7-Valve
8-0il filler cap
9-Rocker shaft
10-Rocker arm
ll-Rocker
cover
l2-Rocker shaft stay
l3-Push rod
Cylinder head - Cross section
Cylinder head gasket
A steel-and-asbestos gasket
is
used for the
head gasket. Its internal edges for cylinder bores
are
grommetted
with stainless steel sheet to
resist the high combustion
heat
and pressure
encountered there.
Both
faces
of
the gasket are
coated with a sealing compound.
Each replacement gasket comes with its
surfaces so treated
that
no sealing
compound
is
required when installing
it
during engine reas-
sembly.
The later
production
of
this engine uses gasket
whose base material
is
carbon called "Gra-Foil."
Cylinder head gasket
Valves and valve springs
The material
of
intake valves
is
a heat-resistant
steel; the head diameter
is
sized large for in-
creased intake efficiency. The heads
of
exhaust
valves are faced with a special alloy, which
is
deposited by welding.
Valve springs, made
of
a high-carbon spring
steel, have their
bottom
ends shaped specially so
that they will solidly seat
on
the cylinder head.
Their top ends are identified by red enamel.
There are no differences in spring retainers and
retainer locks between intake and exhaust valves.
To Next Page
Loading...
Need help?
General
