Subaru Robin Power Products EY44-2 Crankcase, Mainbearing Cover, Crankshaft, Camshaft, Balancer

4-2 CRANKCASE

The crankcase is made of aluminum die-cast and separable on driving shaft side with main bearing cover assembled. Provided on blower side are two ballbearings, each supporting the crankshaft and camshaft.

4-3 MAINBEARING COVER

The aluminum die-castmainbearingcover on the drivingshaftsideallowseasyaccess to the engine interior for inspection simply by removing it. The’fange and boss permit direct coupling of operating machines such as generators, pumps, etc. The oil inlets whichalso serve as oil gauges can be mounted on driving shaft side of Models EY33-2Band EY44 - 2B .

The force-fit balancer shaft and balancer holder mounting boss assure easy mounting of the balancer mechanism.

4 4 CRANKSHAFT

The crankshaft is machined from carbon steel forging with an induction hardened crank pin. The breaker cam is provided on blower side, while crankshaft gear and balancer gear are force-fit on driving side.

4-5CONNECTING ROD and PISTON

The connecting rod is machined from aluminum alloy forging, and forged alloy itself serves as bearing metal at both ends. (Model EY44-2 employs aluminum metal on the large end.)

An oil scraper is provided onthe large endforthepurpose ofsplashinglubricatingoil.Thepiston is machinedfron aluminum alloy casting and provided with grooves for two compression rings, one oil rings, and one skirt ring.

The EY44-2piston has an offset structure at the piston pin center so as to reduce striking sound of piston.

4-6 CAMSHAFT
Thecarbonsteelforgingcamshaftincorporatesintegralintakeandexhaustcamsplusaforce-fitcamgear.	The B-typ
camshaft also serves as driving shaft and it is driven at half the crankshaft speed.
4-7 CYLINDER and CYLINDERHEAD
Thecylinder is made of specialcastironandprovidedwithmanyfinsforassuringexcellentcoolingeffects.The	cylinda
head is made of aluminumalloycastingTheRicardotypecombusionchamberwithasufficientareaassures.	hil
combusion efficiency. The spark plug is tilted to facilitate fuel tank mounting.

4-8 VALVEARRANGEMENT

Theexhaust valve is positioned in theupstreamofthecolling air so thatit is intensivelycooled downforimprov

durability of engine.

4-9 BALANCER

An unbalancedinertiaforceproducedduetocrankshaftandpistonconnectingrodintheverticalandlateraldirection:

balanced bybalancerwhichrotatesat a ratioof 1: 1 in thedirectionoppositetocrankshaft, so thatvibrationsdue

unbalanced inertia force are reduced.

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