Practical sessions - 2-stroke Engines Flashcards
What are the main engine components?
- Pistons
- Cylinder Head
- Crankcase
- Crankcase Shaft
- Flywheel
- Connecting rods
What is a Crankcase?
The crankcase is the “body” that holds all
of the other engine parts together. It’s the
largest part of the engine, but must be
designed to be strong
What is a Crank shaft?
The crankshaft is the part of an engine which translates reciprocating linear piston motion into rotation
How does a Crank shaft work?
The crankshaft has “crankpins”, additional bearing surfaces whose axis is offset from that of the crank, to which the “big ends” of the connecting rods from each cylinder attach.
What is a piston?
The piston is a component usually made of
aluminium. It is located in a cylinder in the
crankcase and is made gas-tight by piston
rings
What is the purpose of a piston?
To transfer force from expanding gas in the cylinder to the crankshaft via the connecting rod
What do the piston rings do?
They provide a sliding seal between
the outer edge of the piston and the inner
edge of the cylinder
What purpose do the piston rings provide?
- They prevent the fuel/air mixture and
exhaust in the combustion chamber from
leaking into the sump during compression
and combustion. - They keep oil in the sump from leaking
into the combustion area, where it would
be burned and lost
What are Connecting Rods used for?
Connecting rods are most usually made of steel for production engines, but can be made of aluminium or titanium for high performance engines
Why are connecting rods made of aluminium?
For lightness and the ability to absorb high impact at the expense of durability
Why are connecting rods made of titanium?
For a combination of strength and lightness at the expense of affordability
