Mechanical ArrangementMechanical Arrangement
Piston EnginesPiston Engines
The main bits and pieces that make up the piston engineThe main bits and pieces that make up the piston engine
Mechanical Arrangement - BasicsMechanical Arrangement - Basics
Mechanical Arrangement - BasicsMechanical Arrangement - Basics
A
B
Hand force in direction ‘A’ gives rotational
force on nut
Leg force in direction ‘B’ gives rotational
force on pedal/crank propels bicycle along
Mechanical Arrangement - BasicsMechanical Arrangement - Basics
Cylinder
Piston
Connecting Rod
Crank Shaft
‘Big-end’
Gudgeon Pin Main
Bearings
Offset Bearing
Counter Balance Weight
Mechanical Arrangement - BasicsMechanical Arrangement - Basics
11
2233
44Pistons
Crankshaft
Rear
Front
Flywheel attachment
flange
Timing Belt and Water Pump
driving pulley location
Main Bearings
Mechanical Arrangement – Main PartsMechanical Arrangement – Main Parts
Sump (Oil Tank)
‘Rocker Box’ Cover
Cylinder Block
Flywheel
Valve Gear
Crankshaft and Pistons
Exploded View of the Engine
Cylinder Head Assembly
Timing Shaft
Mechanical Arrangement – Valve GearMechanical Arrangement – Valve Gear
Valve Operation
The Inlet Valve needs to be open to allow fuel/air mixture
in
The Exhaust Valve needs to be open to allow burnt gases
out
Inlet Valve Exhaust Valve
Mechanical Arrangement – Valve GearMechanical Arrangement – Valve Gear
Rocker
Rocker Shaft
Closing spring
Valve Seat
Push Rod
Cam Shaft
Inlet Valve Closed Inlet Valve Open
Valve Lift
Push Rod Mechanism
Overhead Cam -No Rocker
Overhead Cam and Rocker Push Rod
Mechanism
Mechanical Arrangement – Valve GearMechanical Arrangement – Valve Gear
Mechanical Arrangement – Valve GearMechanical Arrangement – Valve Gear
Modern Engines use a toothed rubber belt to drive the cam shafts
Cam Drive Mechanism
Crankshaft and
Pistons
Twin Cam System
Chain Tensioners
Put it all together
Mechanical ArrangementMechanical Arrangement
How does it work?