Automotive 1 Flashcards
Engine block
Frame work for engine cylinders and reciprocating assembly
Piston rings
seals Pistons to the cylinder and prevents combustion gases from leaking past. Oil rings prevent oil from the crankcase from getting into the combustion chamber
Crankshaft
Converts linear motion of pistons to rotary motion
Cylinder head
Houses combustion chamber, intake and exhaust valves, and intake and exhaust ports
Intake valve
Allows air fuel mixture to be drawn into the combustion chamber, when closed seals combustion from intake port
Exhaust valve
Allows waste gases to be removed from combustion chamber, when closed seals exhaust port
Camshaft
Responsible for opening and closing of engines intake and exhaust valves, turns at 1/2 speed of engines crankshaft
Inline cylinder arrangement
Simplest arrangement, all cylinders line up in a row, practical for four and six cylinder engines
Horizontally opposed/flat cylinder arrangement
All cylinders lying in a horizontal plane with half facing away from the other half with crankshaft in between
Overhead valve (OHV) camshaft location
Located in engine block and intake and exhaust valves located in cylinder head. Valves above piston and combustion chamber
Overhead cam (OHC) camshaft location
Camshaft above valves, valve operating becomes simpler and lighter
Firing order
Common 1-3-4-2
C-8 engine 1-8-4-3-6-5-7-2
Diesel engine
Or compression ignition engine. Much simpler and reliable as hey don’t have spark ignition system. Use high compression ratio to generate sufficient heat of compression to ignite
Stoichiometric ratio
Ideal ratio of air to fuel, responsibility of the engines fuel system to maintain that balance
Lean vs rich air-fuel ratio
Lean is too much air and not enough fuel, burns relatively slowly. Rich is too much fuel and not enough air, burns quicker
Before top dead center (BTDC)
Ignition 5 degrees BTDC means the spark took place when the crankshaft was 5 degrees rotation BTDC
Detonation
When air-fuel mixture explodes rather than burns, can happen when air-fuel mixture is lean
Air-cooling
Air is circulated over cooling fins outside the engine to remove excess heat
Water cooling
Uses liquid coolant to pick up excess heat then rejects heat through radiator
Water jacket
Hollow sections of the engine block and cylinder head that allow coolant to be transferred through them
Thermostat
Controls engine temperature by allowing coolant to flow into the radiator when coolant temp rises above a certain level
Bypass tube
Allows coolant to flow back into the water pump from the cylinder head when the thermostat is closed
Radiator hoses
Flexible hoses that allow hot coolant to flow between the engine and the vehicle’s radiator
Radiator
Responsible for transferring heat from the coolant to the outside air
Radiator cap
Maintains pressure in the system
Engine oil
Major component in lubrication system. Made up of base oil and additive package. Viscosity is important, SAE 5 is low SAE 50 is high
Oil pan
Forms reservoir for oil at the bottom of the engine
Oil pickup tube and screen
Immersed in engine oil, filters out large solids and directs oil into the oil pump
Oil pump
Pumps oil through oil galleries, driven by camshaft
Oil galleries
Passages/”drillings” in engine assembly that transports oil to critical components
Dry sump
Complex, typically only in race vehicles
Wet sump
Engines oil reserve is located at the bottom of the engine in the oil pan
