Chp2 Construction Part 2 Flashcards
(23 cards)
What is the cylinder barrel
The housing of the piston, the inner surface must be smooth and lubricated to reduce friction
Why is the outer surface kf the cylinder barrel covered in fins
To ensure greater surface area in contact with ambient air for cooling
What may a cylinder barrel also have for cooling
Hollow passages to circulate water
What are the 5 components of a cylinder head
Valve assembly
Exhaust port
Intake port
Spark plug port
Fuel injector port
How are the poppet valves opened
They pop into the combustion chamber after being activated by the rocker arm after the rotation of the camshaft
How are the poppet valves closed
By a set of springs
(2 springs to ensure redundancy)
What is the ratio of camshaft to crankshaft rotation and why
1 : 2
The gear of the camshaft is bigger than the crankshaft
Why does the valves need to be fully closed and the engine syncronised
To avoid loss of power / wasted energy
What is the purpose of the hydraulic tappet
It can absorb the expansion of the valve stem due to heat which then means the valves can still stay fully closed
What colour smoke do you get when burning oil
Blue
What colour smoke do you get when burning fuel
Black
What is a camshaft
The element which is responsible for the timings of valves, it will open the valves every 4 strokes
What are the 3 types of drive for the gears between a crankshaft and camshaft
Belt drive
Chain drive
Gear drive
Equation for engine displacement
Swept volume x number of cylinders
Equation for total volume
Swept volume + clearance volume
What is swept volume equivalent to
Cylinder displacement
Equation for swept volume
Bore area x stroke
Equation for stroke
Throw x 2
Equation for compression ratio
(Swept volume + clearance volume) / Clearance volume
Or
(Total volume) / clearance volume
Equation 2 for swept volume
Pi x [(bore)²/4] x stroke
What is a firing order
The order in which the power stroke occurs in each cylinder
What should you include in a firing order table
Number of cylinders
Number of strokes
