1 Flashcards
What is DI
Direct injection
What is TDC
Top dead centre
What is BDC
Bottom dead centre
Two basic piston designs in commercial and off road vehicles
Trunk type piston
Articulating piston
Trunk type pistons
Aluminum trunk
Forged steel trunk
Composite steel trunk
What is CFA
Ceramic fibre reinforced aluminum
What are CFA And SCFR?
Fiber reinforced Aluminum liner practice
Squeeze cast fiber reinforced
What is SCFR used for
Is used to toughen up the crown area of the piston
What is gas blowby
Gas blowby is when gases get by all compression gas diminishes by 50 % past the top ring
What is bearing spill
Oil for the shaft support spills to the timing gear housing
How hot does a gear need to be before putting it in
300 degrees f
Tempilstick
Heat indicating crayon used to determine exact temperature
What tool is used to install gears
Hand actuated arbor press
What is SOHC
Single overhead camshaft
What is DOHC cam shaft
Double overhead camshaft
Advantage of helical gears
Increased tooth contact area
That lowers unit forces
Advantages of sour gear
The design offers much lower thrust loads
What is gear backlash
The space between teeth in interlocking gears for lubricant to flow
What is S I
Spark ignition
Fuel is ignited by an electrical spark
What is bore
The diameter of cylinder base
What is stroke
The distance which a piston travels from BDC to TDC
What is cetane
Used for ease of ignition
Cetane numbers are used to indicate combustion Speed of fuel
Number 1 and 2 diesel
1 flows easier when cold
#2 carry heavy loads/ fuel economy
What is Pour point
The pour point is when it gets to cold and does not flow
What is ULSD
Ultra Low Sulfur diesel
What is LPG
liquefied Petro Gas
what is ULSD good for
Acid rain due to silver content
Major uses for Diesel engines
Construction
Ag and farm
Transport
Forestry
Marine
Electric Gen plants
Advantages of Diesel engines
More efficient
Fuel vapor not explosive
Greater torque
Durable engines
No vapor locks
Can use more fuel mixtures
Dis advantages of Diesel engines
Bigger heavier engine
High compression ratio
More expensive
Fuel gets cold in some climates
Nosier
Exhaust stink
Internal combustion engine
Engine that produces power by burning fuel inside a combustion chamber
Two types of Internal combustion engines
SI engines
CI ENGINES
What does compression ratio 16:1
Cylinder air is compressed into 1/16 the space at top of piston stroke
Ratio compared gas to diesel
Gas 8:1
Diesel 16:1
How many gallons of air per gallon does a Diesel engine use
12-15000
Basic parts to fuel system
Injection nozzles
Injection pump
Filter
Transfer pump
Fuel tank
2 way Diesel engines are cooled
Liquid coolant
Air cooled
What is ideal idling temp
165 to 205
Over heating problems
Cylinder head and block and crack
Ring valves may seize
Bearing may be damaged
Over cooling affects
Increased engine wear
Improper lubrication
Increased fuel consumption
Increase engine compression
Sludge
Air cooled advantages
Less weight
Less maintenance
Less down time
No coolant concerns
Quicker warm up
Dis advantages of air cooled
Length of engine
Nosier
Higher operating temp
More frequent cleaning
Functions of lube system
Reduce shock wear and friction
Seals compression
Cleaning
Quiets engine
Intake and power stroke go?
Down to BDC
Compression and exhaust stroke are up to what point TDC ADTC BDC ABDC
Up to TDC
Valve overlap does what?
Purged and cools cylinder happens when piston comes up
Scavenging does what
Purges cylinder
What two things are most important when choosing oil
Viscosity
Service classification
What is Viscosity
A measure of a liquids resistance to flow
Higher temp= lower viscosity
What is the SAE
Society of auto engineer
3 most common oil additives
Oxidation inhibitors
Corrosion and rust inhibitors
Detergent dispents
Scavenge is to?
Expel gases from en engine cylinder
What is the cam shaft
Brain of the engine
Controls valve operation
Roared at 1/2 crank shaft speed
Helps determine firing order
Determines the useful RPM range
When will cylinder pressure begin to rise rapidly
Just after TDC and should peak at 23 degrees
What is Compression ratio ?
A measure of the cylinder volume when piston is a TDC VS BDC
Compression pressure ?
Cylinder pressure on compression stroke
350-700 psi
What is atmospheric pressure
Pressure exerted by weight of atmosphere
14 696
When does crank throw leverage peak
Just before 90 degrees ATDC
Intake valve closing is the most?
Crucial valve
what is NA
Naturally aspirated
What is kinetic energy
The energy of motion
What is DEP ?
Diesel electric parallel drive
Powering a generator /motor/battery bank and mechanical drive train
what is DHS
Diesel hydraulic series drive
Small engine that powers hydraulic motor/pump and accumulator
Vehicle can only move from Hydraulic pump
What is DHP
Diesel hydraulic parallel drive
Vehicle can move from hydraulic pump or mechanical
Where does scavenging take place in a four stroke engine
Valve overlap
The energy of motion is known as
Kinetic energy
Who is Rudolph diesel
Invented four stroke cycle compression ignition
What describes engine displacement
Total piston swept volume
The tendency of an object in motion to stay in motion is known as
Inertia
Where does scavenging take place In a four stroke cycle diesel
Valve overlap
Ideally, where should peak cylinder pressure occur during the power stroke
10 to 20 degrees ATDC
Which sub circuit deals with Cam,valvetrains and mechanical actuation
Feedback assembly
When running an engine at idle speed what would be optimum location for peak cylinder pressure
15 Degrees ATDC
How many RPM to start an engine
150
Engine typical heat
405
495
Line haul truck compression ratio
17-1
When is fuel Injected
10 degrees TDC
Most power in what stroke
ATDC TDC BDC
15 degrees ATDC
Air cleaners
Oil
Filter
Dry
Air cooled liner advantage
No cavitation
Proper definition of viscosity
Resistance to shear break down of oil
Atmospheric pressure
14.7
Most popular piston
Monotreme steel alloy
Major thrust is on what side when going clock wise
Major thrust on left minor anti thruston right
Piston ring seals?
Static pressure
Advantages of fracture rod
Improve oil clearance
Reduce cost
Piston nozzle uses
Precise aim
Cool piston
Main bearings
Reduce friction
A replacement surface
Under sized bearing =
Shaft diameter
Bearing spread for
Tension
Checking End play at thrust washer
Check thrust for 0.0005 to 0.0012 ‘
Oil pump is?
Positive displacement
Oil coolers get rid of heat at?
250 degrees also can be oil break down