Subaru Robin EX13 - Manual (Page 11)

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4-1 CYLINDER AND CRANKCASE
The cylinder and crankcase are aluminum die-casting
as a single piece. A special cast iron cylinder liner is
molded into the aluminum die-casting.
The crankcase has a mounting surface on the output
shaft side to which the main bearing cover is attached.
The cylinder is inclined to the right at an angle of 25
degrees from the horizontal as viewed from the output
shaft side.
4-2 MAIN BEARING COVER
The main bearing cover is an aluminum die-casting,
which is mounted on the output shaft side of the
crankcase. By removing the main bearing cover, the
inside of the engine can be inspected with ease. Pilots
and bosses are machined into the cover to facilitate the
direct coupling of the engine with machines such as
generators and pumps. There is an oil filling port, with
oil gauge, on either side of the cover.
4-3 CRANKSHAFT
The crankshaft is made of spheroidal graphite cast iron,
and the crank pin is high-frequency induction-hardened.
The crank sprocket used to drive the chain and the
gear used to drive the governor gear are pressed into
the output end of the shaft.
4-4 CONNECTING ROD AND PISTON
The connecting rod is a specially heat-treated aluminum
alloy die-casting. Its large and small ends function as
bearings. A splasher built into the connecting rod
lubricates by splashing engine oil. The piston is an
aluminum alloy casting with grooves for mounting two
compression rings and one oil ring.
Fig. 4-1
Fig. 4-2
Fig. 4-3
Fig. 4-4
4. GENERAL DESCRIPTION OF ENGINE COMPONENTS