Subaru Robin EX30 - Manual (Page 9)

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4-5 PISTON RINGS
The piston rings are made of special cast iron. The profi le of the top ring is a barrel face or tapered face, and that of
the second ring is a tapered face. There are 2 types of oil ring depending on the engine specifi cation.
As those are interchangeable, the cutter ring with coil expander type can be selected as the spare part.
TOP
RING
OIL
RING
1
2
BARREL
THREE-PIECE
CONSTRUCTION
1
2
4-6 CAMSHAFT
The camshaft and the sprocket are made of special
sintered alloy. They are constructed as a single piece.
The camshaft is provided with intake and exhaust
cam, and the decompression release lever is mounted
on the sprocket shaft end side.
4-7 VALVE ARRANGEMENT
This engine has a chain-driven overhead cam and
overhead valve construction, with a single cam
performing both intake and exhaust operations.
4-8 CYLINDER HEAD
The cylinder head is an aluminum die-casting with
a pent roof combustion chamber construction. The
intake and exhaust ports are arranged in a cross
direction to improve combustion effi ciency.
DECOMPRESSION
RELEASE
LEVER
EXHAUST VALVE INTAKE VALVE