More Shit Flashcards
Colours of gas
Mogas 91 - purple, red, bronze and orange Mogas 95 - yellow,orange Avgas 100LL - blue AvTur - straw coloured or clear Avgas 100/130 - green
Colours of hydraulic fluid
Vegetable based - blue
Mineral - red
Synthetic - purple,green, amber
The ignition switch of a magneto is connected where?
Between primary winding and earth.
What is crank angle
The position of the engines crankshaft in relation to the piston as it travels inside the cylinder wall.
What is ineffective crank angle?
the piston travels much further in the first 90 degrees of rotation of the crankshaft than it does in the second 90 degrees.
When split into 15º the distanced travelled of the piston is more in the first half than the second, so second half is the ineffective crank angle which occurs near BDC
What is the process of the combustion cycle.
Induction stroke - fuel air mix is sucked into cylinder through open inlet valve. As piston descended pressure is reduced in cylinder making fuel air mixture pressure increase.
Compression - inlet valve closes, piston moves back towards cylinders head temperature increases. As it completes compression stroke its ignited.
Power - piston is pushed down cylinder in power stroke due to strong pressure in compression. And prior to completion of the stroke exhaust valve opens.
Exhaust - piston moves back up and the burnt gases are forced out the cylinder to atmosphere via exhaust valve and manifold.
What is spark advance?
Where spark plug ignites fuel-air charge before TDC so that highest pressure is developed before conrod and crank shaft are at 90º.
Typically between 15-40º before TDC
What happens at idling rpm for intake manifolds?
The pressures in intake manifold are very low and some exhaust gas is drawn into cylinder during valve overlap.
Incoming fresh charge becomes diluted with the spent gases which remain in the cylinder.
