Stationary Engine Fundamentals Flashcards
What is a cylinder head?
The area that seals and confines the expanding gas and is situated on top of the cylinder
What is the block/frame?
The main structure of the engine that supports all working parts to keep that in alignment
What are the engine cylinders?
Liners, sleeves or cylinders
Hollow tubes in which the pistons slide up and down to harness the expansion of burning gases.
What are the pistons and piston rings?
Pistons form the moveable end of the combustion chamber, they transmit the power from the expansion of the burning gases to linear motion.
Piston rings help to seal the burning gases to harness as much energy as possible
What are connecting rods?
The link between the piston wrist pin and the crankshaft
What is the crankshaft?
Changes the linear motion of piston to continuous usable rotary motion
What is the camshaft, lifters and rocker arms?
The camshaft (cam) opens and closes the intake and exhaust valves.
Lobes of the cam push on the lifters which pushes on the push rods and rocker arms.
Rocker arms change direction of motion and open the valves
What is the flywheel?
The flywheel stores energy and smoothes the power pulses from the piston
What is the balancer?
Harmonic balancer, vibration dampener or torsional vibration dampener
Reduces the crankshaft torsional vibrations
What are the timing gears?
They link all parts of the engine together so that all events in the engine occur at the correct time
What does TDC stand for?
Top dead centre
What does BTDC and ATDC stand for?
Before top dead centre
and
After top dead centre
What does HP stand for?
Horsepower
What does BHP stand for?
Brake horsepower
What is an engine?
A mechanical device that converts the chemical energy stored in a fuel to heat and then into mechanical energy
What is a motor?
A mechanical device that converts fluid or electrical energy into mechanical energy
What is torque?
The twisting force acting at a radius that produces a turning momentum
Torque=Force x distance (a turning effect)
What are the 4 different types of power?
Horsepower
Friction horsepower
Indicated horsepower
Brake horsepower
What is friction horsepower?
The power required to overcome engine frictional and pumping losses
FHP= IHP - BHP
What is indicated horsepower?
The theoretical power of an engine, does not take any friction or pumping losses into consideration
What is brake horsepower?
Actual power measured at the end of the crankshaft
BHP= IHP - FHP
What are the 3 kinds of friction?
Sliding
Rolling
Fluid
What is inertia
The tendency of an object in motion to stay at motion
What is considered the stroke of a cylinder?
From TDC to BDC
What is a square engine?
An engine with the same dimensions for bore diameter and stroke length
What is the difference between an oversquare and undersquare engine?
Oversquare engines have a larger bore diameter then stroke length
Undersquare engines have a longer stroke length then bore diameter
How do you calculate piston displacement?
Area of bore X Length of stroke
3.14R (2)
What is engine displacement?
It is the piston displacement multiplied by the number of cylinders
What is clearance volume?
The volume remaining above the piston when it’s at TDC
Lyon do you calculate compression ratio? (CR)
CR = Displacement + clearance volume / clearance volume
/ = division symbol
What is the ratio for volumetric efficiency?
Volume of atmospheric air drawn into cylinder on the intake stroke : the cylinder displacement
What is blowby?
The leakage of burned and unburned gases past the compression rings into the crankcase
What are the three things needed for combustion?
Fuel \+ Air \+ Spark
True or false, the fuel needs to be atomized and mix with the oxygen in order to burn?
True
What are the 4 strokes on a 4-stroke engine?
- Intake
- Compression
- Power
- Exhaust
How many degrees of rotation must a 4 stroke make to complete its cycle?
270°
How many degrees of rotation must a 2 stroke make to complete its cycle?
360°
Where should you stand when determining crankshaft rotation?
The main power end of the engine
How are engine cylinders usually numbered?
Opposite to the flywheel
What is a running mate?
Only applies to 4 stroke engines and refers to the cylinders that have the same pistons reaching TDC at the same time
What are the 6 different cylinder and crankshaft arrangements?
- Inline
- V-type
- Integral
- Opposed piston
- Horizontally opposed
- Radial
What are the 3 different valve arrangements?
- Overhead valve
- Multi-valve
- Flat head
What problem does an overhead cam solve?
The problem of excessive valve train mass and so many moving parts.
What is the job of a pushrod?
Transmit motion to the head and valves from the camshaft
What is a naturally aspirated engine?
Engines that draw air into the cylinders using differential pressure only
What is an artificially aspirated engine?
An engine that uses some mechanical means to fill the cylinders with air like a blower or (pressure under piston)
What RPM is considered a low speed engine?
500 rpm and below
What rpm is considered a medium speed engine?
500 rpm to 1000 rpm
What engine rpm is considered high speed?
1000 rpm and above
How does a Diesel engine ignite the fuel air mixture?
It uses the heat of compression to ignite the fuel-air mixture to combust
Do spark-ignition engines have a lower compression ratio then Diesel engines?
Yes because they have a spark plug where as a Diesel engine needs high compression ratios to generate high heat and ignite the fuel-air mixture
What is a perfect vacuum?
29.92 inches of mercury
How many watts is 1 hp?
746 watts
What determines firing order?
The position of the crankshaft throws and the arrangement of the lobes on the camshaft
