Textron Lycoming O-540 Series - Page 15

TEXTRON LYCOMING
OPERATOR'S
MANUAL
0-540 & 10-540 SERIES SECTION 1
DESCRIPTION
The 0-540 and 10-540 series are six cylinder, direct drive, horizontally
opposed, air cooled engines.
In referring to the location of the various engine components, the parts
are described in their
relationship to the engine as installed
in the airframe.
Thus the power take-off end is considered the front; the accessory drive
end, the rear. The sump section is considered the bottom and the opposite
side of the engine where the shroud tubes are located the top. Reference
to the left and right side is made with the observer facing the rear of the
engine. The cylinders are numbered from front to rear, odd numbers on
the right, even numbers on the left. The direction of rotation for accessory
drives is determined with the observer facing the drive pad.
Cylinders - The cylinders are of conventional air cooled construction with
the two major parts, head and barrel, screwed and shrunk together. The
heads
are made from an aluminum
alloy casting with a fully machined
com-
bustion chamber.
Rocker shaft bearing supports
are cast integral with the
head along with
housings to form the rocker boxes
for both valve rockers.
The cylinder barrels,
which are machined from
chrome nickel molybdenum
steel forgings, have deep integral
cooling fins and the inside
of the barrels
are ground and honed to a specified finish.
Valve Operating
Mechanism - A conventional
type camshaft is located above
and parallel to the crankshaft.
The camshaft actuates hydraulic
tappets which
operate the valves through
push rods and valve rockers.
The valve rockers
are
supported on full-floating steel
shafts. The valve springs bear
against
hardened
steel seats and are retained
on the valve stems by means
of split
keys.
Crankcase - The crankcase assembly consists of two reinforced aluminum
alloy castings, fastened together by means of studs, bolts and nuts. The
mating surfaces of the two castings
are joined without the use
of a gasket,
and the main bearing bores are machined for use of precision type main
bearing inserts.
1-1