The Year 6 Science inquiry students met with Mr Sayer this week for a most interesting task – dissembling an engine. Firstly Mr Sayer explained the difference between a 2 stroke and a 4 stroke engine. For todays activity we were just going to focus on the 2 stroke engine.
We started out with a brainstorm about ‘combustion’ which means the burning of any fuel. The students understood that for combustion to occur there must be three elements –
Then Mr Sayer slowly pulled apart the engine of a weed trimmer taking care to explain each component and it’s role in the engine system.
Here are a few photos with supporting facts to show what we learned about 2 stroke engines.
SPARK PLUG: Ignites fuel air mixture above the piston to cause the fuel to burn (combustion)
CRANKSHAFT: Converts up/down motion of piston to rotary motion.
MAGNETO: Electric generator to create spark at correct moment in the cycle.
PISTON & CONNECTING ROD: Gas at high pressure forces piston down.
FUEL TANK: holds petrol and oil mixture.
AIR FILTER: prevents dirt and dust entering engine and causing wear.
CARBURETTOR: mixes fuel into air in correct proportions and controls amount of fuel entering engine to control power output.
CORD PULL STARTER: provides initial rotation to start engine.
We thank Mr Sayer for providing such an interesting activity with an accompanying powerpoint to help explain all the important facts.