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Unformatted text preview: of the cylinder. The spent gases
from the burning mixture are then released to the exhaust system. A
small amount of further piston travel down the cylinder now exposes
the intake port. At this point, the now pressurized mixture in the crankcase is released
into the combustion chamber through the intake port. A piston dome design, unique to 2
cycle engines, is used to help 'sweep' the chamber clean of spent exhaust gases by
directing the incoming rush of air/fuel up towards the cylinder head and then down
towards the exhaust port. Faculty of Engineering & Applied Science
Memorial University of Newfoundland ENGI 1030 Lawnmower Disassembly/Assembly As the crankshaft continues its rotation, the piston will eventually reach bottom and
return to the top, repeating the Intake/Compression cycle. It can be seen by the overall
design that unless the reed valve is mechanically operated, i.e. is actually a rotary valve
used to accomplish the same one-way function, the crankshaft can rotate in either
direction making no difference in how the engine runs. Wankel Rotary Engine Intake
The fuel mixture is drawn in by the vacuum created as the chamber increases in volume
with the clockwise rotation of the rotor.
The fuel mixture is compressed as the chamber drastically reduces in volume with the
further rotation of the rotor.
At the ideal time (varies depending on application) the spark plugs energize, igniting the
fuel mixture. The burning mixture rapidly increases in pressure and pushes on the rotor,
forcing it to continue its rotation. It is in this phase of the cycle that power is delivered to
the central crank or eccentric shaft
With the continued rotation of the rotor, the spent mixture is then allowed to expand as it
is pushed from the chamber into the exhaust system. Intake Compression Ignition Faculty of Engineering & Applied Science
Memorial University of Newfoundland Exhaust ENGI 1030 Lawnmower Disassembly/Assembly Fuel System
Gasoline engines cannot run on “liq...
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- Fall '11