2. Module Guide 2010
AUM 301
Introduction
• The comprehensive content of this module
focuses on advanced motorcycle technologies
and examines all the major motorcycle systems
including engine and drive line. Electronics.
Braking and suspension.
• The module also considers emerging and future
technologies including environmental factors
and evaluates how these emerging technologies
will affect future motorcycle design and
performance
3. Module guide 2010
AUM 301
• An introduction to various simulation
techniques completes the content.
• The module is primarily delivered through
lectures and practical laboratory sessions
supported by tutorials with comprehensive
course material available via black board.
4. Module teaching team
• The module teaching team comprises:-
– Module leader: Denis Marchant
– Teaching team
• Richard D Atkins
• Owen Swinered
• Barry Wade
5. Module Time table
• The module content will be delivered over
5 separate days through a combination of
formal lectures tutorials and practical
laboratory sessions ( as appropriate).
• Approximately 35 hours of contact time will
be provided.
• Students are required to spend at least
115 additional hours of private study.
6. LECTURE PROGRAMME
• 15th March (Richard Atkins)
– am
• Introduction/ legislation & environmental Factors/
Combustion and emissions
– Pm
• Engine management systems/ electrical and
electronic systems
7. LECTURE PROGRAMME
• 16th March (Owen Swinerd)
– am
• Engine construction/ balance/ lubrication and
Cooling
– pm
• Engine construction/balance/lubrication and
cooling
8. LECTURE PROGRAMME
• 17th March (Owen Swinered)
• am
– Transmission and drive line systems
• pm
– Transmissions and driveline systems
10. LECTURE PROGRAMME
• 19th March ( Owen Swinered)
– am
• ABS & Linked Braking Systems
– pm
• Suspension Technology
11. Assessment
• The ;learning outcomes will be assessed
by two individual assignments of equal
weighting
• Course work: 100%
• It is a requirement to pass each element of
assessment in order to achieve an overall
pass in this module
12. Module aims
• To introduce the students’ to aspects of
Advanced Motor Cycle technology
• To provide a detailed understanding of
Current and Developing Technologies
13. Learning outcomes
On completion of the module students will be able
to :-
1. Demonstrate an in-depth knowledge of
advanced motorcycle
engine/Driveline/Electronics/Braking &
suspension technologies
2. Identify and evaluate how emerging
technologies will affect motorcycle
Design and Performance
14. 3. Select use and evaluate appropriate tools
for testing and simulation of motorcycles
and their sub-systems
4. Critically analyse and interpret test data
and recommend appropriate solutions
Learning outcomes
On completion of the module
students will be able to :-
15. To day we will review the following
• Legislation
• Environmental factors
• Combustion
• Emissions
• Carburettors
• Fuel Injection
• Ignition
• Engine management systems
• Electrical and electronic systems
16. Legislation Global harmonisation
• Recently, global harmonisation of motorcycle
manufacturing standards has become a hot
topic.
• Harmonisation means that manufacturers will be
required to comply with international set
standards on:
– Allowable noise
– Exhaust gas emissions
– Horse power limits
– Anti tampering devices (e.g.bolts that shear if you try
to remove them)
17. What does this mean for the
individual enthusiast
• The concept behind shear bolts and other anti
tampering devices is to ensure that the
consumer is unable to remove and modify parts
of the motorcycle such as the exhaust system,
induction, suspension etc.
• It will be interesting to see how standardisation
of motorcycle manufacturing fits into overall
global economics
18. Anti-tampering
Shear bolts ?
• Problem
– No prescriptions related to easily modifiable and manually
adjustable multi-mode mufflers
• Proposed solution
– Legal language to prevent approval of mufflers designed for tampering
– Performance requirements for multi-mode mufflers (test all modes)
Anti-tampering
/ contructional
requirements
19. Advantages for Motorcycle OEM’s
• Currently, all MC OEM’s have multiple assembly lines.
• These lines build bikes for each market, viz. USA,
Japan, Asia generally and Europe.
• Through standardisation, the OEM’s would realise major
savings in manufacturing costs by utilising only one
assembly line instead of three or more.
• Every bike off the assembly line could be sold anywhere
in the world.
• As all bikes would be built to Global standards,
manufactures would have to subject bike models to one
type test approval procedure, as opposed to the multiple
approval tests currently required for World exports
20. Disadvantages for Motorcycle
OEM’s
• Some manufactures will have to retool assembly
lines and retrain employees.
• Some will lack experience in meeting noise and
exhaust emission regulations.
• Some will have to invest significant resources
into the redesign of fuel, engine and exhaust
components.
• Some will say that Global harmonisation will kill
off advanced developments and this is a most
serious concern.
21. Impact upon Motorcycle Design
• Will they all look, sound and perform alike?
• The Global standard will place greater demands
on OEM engineers and it is felt that whilst
technology will evolve along similar lines, it will
not necessarily translate into look alike
motorcycles that perform in the same way.
• Regarding noise emissions, by adhering to a
certain dB level then all bikes of the line would
sound the same, near zero noise at idle and
very little under load.
• Reducing noise from the tail pipe and the engine
could mean a reduction in power.
22. Air-cooled machines ?
• The death of air-cooled engines in the
future is highly probable.
• From the exhaust emissions standpoint, all
future motorcycles could well be fuel-
injected with three way catalytic
converters, on board diagnostics and anti
tampering measures
23. • Excessive in-service noise is a problem mainly for motorcycles.
• Many motorcycle drivers think that a motorcycle should emit a great deal of sound
and therefore after purchase or legal testing of a motorcycle almost immediately
exchange the legal exhaust silencer with another and much noisier one.
• A motorcycle industry study concluded that a high proportion of motorcycles in
traffic in Europe have exhaust silencers that are illegal from the noise point of view
[IMMA, 1996].
• Of the European countries where surveys were conducted, the estimated
proportions of all machines in use with illegal replacement exhaust silencer systems
(RESS) ranged from 11% to 59%, the average being 32%.
• The impression is that this proportion is increasing, and it is argued that lowering of
emission limits for new machines will only result in an increase in illegal RESS
(replacement exhaust silencer systems ).
Noise level legislation , motorcycles
Study in 1996 leading to plans for Global
standards
24. Green Machines
• The high performance electric motorcycle
is already with us.
• Kinetic energy recovery as utilised in this
years F1 racing cars will be a must.
– Energy from braking
– Energy from exhaust heat
• Re-cycle able materials will be utilised in
the manufacture of all key components.
31. Phasing loss
Individual cylinder MBVT is not
equal to the overall engine MBT
Torque
(Nm)
Spark Timing (Degrees BTDC)
No4 No1
No3 No2
Overall MBT
32. IMEP v CA of 50% mass burned
One cylinder average at 5 different spark timings
MBT timing
Cyl 2
CA50% Mass Burn average
Retard
Advance
Combustion phasing loss deducted from
individual cylinder MBT
33. IMEP vCA50 mass burned,
individual cycles at five different
spark timings
MBT timing
Cyl 2
Indicated
Cycle
IMEP
Indicated cycle crank angle 50% burn
35. Phasing Efficiency Loss Summary
• Overall engine loss when spark timing differs from
overall engine MBT
• Individual cylinder loss when individual cylinder MBT
differs from overall engine MBT
• Individual cycle loss when individual cycle phasing
(CA50) differs from optimal phasing
There will always be phasing efficiency loss
40. Combustion Phasing
Angular relationship
between the combustion
process and piston
position. Normally
expressed as either the
crank angle at which
50% of the inducted
charge mass has
burned(CA50),or the
crank angle location of
peak pressure (LPP)
41. Heat Release
What is it?
Analysis of cylinder pressure from a firing engine to determine
the burn history of the combustion event on a crank-angle –by-
crank-angle basis
55. Before we start
• 18% of all global emissions are from meat
farming.
– Cows
– Sheep
– Chickens etc
• 30% from natural forest decaying vegetation
• 35% from natural volcanic activity
• We need to think about the 17% FROM all
SOURCES.
56. The Atmosphere
• The atmosphere surrounding our earth is a
very thin layer.
• On this scale, a line 0.005mm would be a
good estimate
Earth
57. Pressure
• What we term atmospheric pressure is
due to the downward force of the
molecules in the air
Altitude
Pressure
58. Weight
• Air has a mass !
1 cubic metre = 1Kg
1 Mole = 22.4 Litre = 29 grams of air
59. The air that you breath
• The “Green Brigade” has not looked at the
biggest single source of man-made CO2
emissions – people !
• Each of us emits 365kg of CO2 each year by
just breathing whilst at rest.
• Multiply this by the current population of 6
billion and the total puts UK car, truck and bus
emissions are paled into insignificance.
• An additional 1 million people in the UK will
produce 7,019,230.77 kg per year. 1,000g =
1kg
• Assume 120 g/ kilometre = 10,000 cars over
5,850 kilometers per year.
61. At room temperature petrol or diesel will not spontaneously combust in
air - they will not react with air. The fuel and the air are stable. In
order to get fuel and air to react two things must happen:
a) the fuel and air must be mixed together in the correct proportions,
b) some energy must be added to start the reaction.
In a petrol engine a spark is used to start combustion, in a diesel
engine the heat generated by the compression of the air trapped in
the cylinder is used to start combustion.
How does combustion occur?
62. Diatomic Molecules
• As energy is added to the air within the cylinder the
molecules move faster. The atoms within the molecules
also oscillate relative to each other. Once the molecules
have absorbed enough energy the bonds between the
atoms start to break.
• The bonds between different types of atoms have
different strengths or bond energies. The molecules
containing atoms with the lowest bond energies will start
to disassociate before the molecules containing atoms
with higher bond energies.
63. Composition of air
• Air is a mixture of oxygen molecules and nitrogen
molecules, plus a small amount of other gases. Oxygen
and nitrogen molecules are diatomic, two oxygen atoms
are bonded together to form an oxygen molecule and
two nitrogen atoms are bonded together to form a
nitrogen molecule. The molecules move around freely
because air is a gas at room temperature.
64. Composition of basic constituents
of air and fuel
• Oxygen molecules have a relative mass of 32.
• Nitrogen molecules have a relative mass of 28.
• The mass fraction of oxygen is approximately 20%
• The mass fraction of nitrogen is approximately 80%.
• Carbon molecules have a relative mass fraction of 12
• Hydrogen molecules have a relative mass fraction of 1
65. • Petroleum fuels largely consist of hydrogen and carbon.
Hydrogen is a light atom with a relative mass of 1,
carbon is a heavier atom with a relative mass of 12. The
atoms of hydrogen and carbon are chemically bonded
together to form hydrocarbon molecules.
• The simplest hydrocarbon molecule is methane.
What is fuel made of ?
67. Methane
• One molecule of methane (CH4) consists of one carbon atom
bonded to four hydrogen atoms.
• The relative mass of a carbon molecule is 12 and the relative mass
of a hydrogen molecule is 1, therefore the relative mass of a
methane molecule is 12 + (4 x 1) = 16.
• Hydrogen contributes 4/16 = 25% to the mass, therefore the
hydrogen mass fraction is 25%.
• Carbon contributes 12/16 = 75% to the mass, therefore the carbon
mass fraction is 75%
• Methane is a relatively simple molecule and is a gas at room
temperature, as hydrocarbon molecules become more complex
they become heavier and are liquids at room temperature.
68. Step 1 Consider the case of methane burning in
air. First introduce the air, oxygen & nitrogen
70. Step 3 Add some energy to break the chemical bonds, note some
Molecules with disassociated electrons
71. Step 4 The molecules start to reform, giving carbon dioxide
and water
72. Step 5 All the available methane has been combusted
73. The combustion of methane
• When one molecule of methane is burnt in air, two molecules of
oxygen are consumed. Air contains approximately eight molecules
of nitrogen for every two molecules of oxygen. The products are one
molecule of carbon dioxide and two molecules of steam. The eight
molecules of nitrogen remain in their original state.
• A balanced chemical equation for the combustion of methane is
therefore:
• 1CH4 + 2O2 + 8N2 = 1CO2 + 2H2O + 8N2
74. AVERAGE BOND ENERGIES
804 kJ/mol
498 kJ/mol
945 kJ/mol
CARBON OXYGEN DOUBLE BOND
HYDROGEN OXYGEN SINGLE BOND
NITROGEN TRIPLE BOND
OXYGEN DOUBLE BOND
463 kJ/mol
75. VG9
AVERAGE BOND ENERGIES
330 kJ/mol
498 kJ/mol
945 kJ/mol
CARBON HYDROGEN SINGLE BOND
OXYGEN DOUBLE BOND
NITROGEN TRIPLE BOND
84. Emissions-Constituents (NOx)
Oxides of Nitrogen (NOx)
• Mechanism
– At high temperatures, in the presence of
oxygen,nitrogen molecules react to form NO and NO2
• Main Controller
– Combustion temperature and oxygen availability
89. Fuel cells
• A efficient internal combustion engine has an thermal
efficiency of 30 to 32%
• Fuel cells have an efficiency over 50% ( some claim 68%
• The technology to produce hydrogen from carbonaceous
fuels requires a fuel reformer (partial oxidization and
stem reforming).
• Fuel reforming process is endothermic and loses thermal
energy.
• Thermal efficiency of a fuel reformer is circa 85%.
• Fuel efficiency of a proton exchange membrane fuel cell
is 50% to 55% giving a total efficiency of the fuel cell of
45 to 50% before the electric motor.
90.
91. energy
• The target thermal efficiency of a internal
combustion engine to be competitive with
a fuel cell should be around 50% since
approximately 10% of energy conversion
is expected at the electric generator.
• To meet this challenge, several new
technologies are emerging.
92. Isothermal efficiency of gasoline engines
Road load
Most efficient operating
point
25%
30%
32% 2
1
4
3
Torque
Engine rev/min
1. Thermal dissociation of burned gases and
formation of NOx whose reactions are
endothermic
2. Increase of friction losses
3. Increase of pumping loss
4. Slow combustion and increase of cooling loss
93. by combustion
• Generally speaking the best thermal
efficiency is balanced by combustion
speed and friction loss.
• The combustion speed increases as
engine speed increases, but it also
increases friction loss.
• This is why the best thermal efficiency
point is located at the mid engine
operating range.
94. Possible improvements
• If you try to increase the volumetric efficiency by
turbo or supercharging, it can increase power
output, but the thermal efficiency falls as the
increase in thermal dissociation of burned gases
and the formation of NOx.
• Therefore there remains very few measures to
increase the thermal efficiency of the internal
combustion engine.
95. Dr.O.A. Uyehara
• It has been postulated that a mixture of ionised
water (52%) and fuel oil (48%) can be burned
without air and that its thermal efficiency is 2.3
times greater than the air fuel system for the
same combustor heat transfer layout.
• He does not state how this is done !
• However if it were possible, combustion have to
be over 2000 K so that the thermal dissociation
of oxygen can take place.
97. Old technology “Carbs”
• A carburettor functions by varying the pressure
between the engine and the carburettor.
• Two and Four stroke
– The piston in the 2 stroke goes up and in the 4 stroke
goes down.
– This forms a low pressure within the crankcase
causing the pressure outside to be higher
– Due to this pressure difference, the air is drawn
through the carburettor until the pressure is
equalised.
98. Mixture in the carb.
• The air moving through the carburettor,
picks up and gets mixed with vaporised
fuel inside the carburettor.
• Factors that effect performance:
– Altitude
– Humidity
– Air temperature
104. The first electronic fuel injection
system for motorcycles
• Pump and primary
pressure regulator and air
bleed
• Throttle bodies and cam
operated fuel control
valve
• Speed signal solenoid
valve
• Injectors
• Distribution valve
• ECU
107. Fuel Injection for Motorcycles
• The first true electronic fuel injection system for
motor cycles were produced by Richard Atkins in
Plymouth Devon (1972)
• The system comprised a square law cam
operated variable orifice (opening a throttle
position)
• Speed signal solenoid (FlowaEngine rpm)
• Injector nozzles
• Electric fuel pump
• Basic ECU
110. Parameters for mixture formation and
subsequent engine mapping fuel and
spark.
• Air-fuel mixture
• Excess-air factor
• Adaptation to specific operating conditions
– Cold start
– Post-start phase
– Warm-up phase
– Part and full-throttle operation
– Acceleration
– Over-run
– Altitude and temperature compensation
111. Air-fuel mixture
• The spark-ignition engine requires a specific air
fuel ratio (A/F ratio) in order to operate.
• The theoretical ideal for complete combustion is
14.7:1, and is frequently referred to as the
theoretical stoichiometric ratio.
• Mixture corrections are required to satisfy the
special engine demands encountered under
particular operating conditions.
• The specific fuel consumption is largely a
function of the A/F ratio.
112. Air-fuel mixture cont.
• Excess air is required to achieve the minimum
fuel consumption that would result from
complete combustion.
• In practise, latitude is restricted by factors such
as mixture flammability and limits on the time
available for combustion.
• With current engines, minimum fuel consumption
is found with a A/F ratio corresponding to 15…18
kg air for each kg of fuel.
• 10,000 litre of air used in the combustion of 1
litre of fuel
113. Air-fuel mixture cont.
• As motor cycle engines spend most of their time
operating at part throttle, engines are designed
to operate in this range.
• Rich mixtures provide better performance under
other operating conditions such as idle and full
throttle operation.
• The mixture-formation system must be capable
of satisfying these variegated requirements.
114. Excess-air factor
• The excess-air factor (or air ratio) l has been
chosen to indicate how far the actual air-fuel
mixture deviates from the theoretical optimum
(14.7:1).
• l= Induction air mass/ air requirements for
stoichiometeric combustion
• l= 1: The induction air mass corresponds to the
theoretical requirement
• l<:Air deficiency, rich mixture. Increased output
is available at l = 0.85….0.95
115. Excess-air factor cont.
• l > 1:Excess air ( lean mixture) in the range l =
1.05…1.3. Excess-air factors in this range result in lower
fuel consumption accompanied by reduced performance.
• l > 1.3: The mixture ceases to be ignitable. Ignition miss-
fire occurs, accompanied by pronounced loss of
operating smoothness.
• Spark-ignition engines achieve their maximum output at
air-deficiency levels of 5…15% (l = 0.95..0.85), while
minimum fuel consumption is achieved with an air
excess of 10…20% (l = 1.1…1.2).
• l = 1 provides optimum idling characteristics.
116. Effect of excess – air factorl
a) Rich mixture b) Lean mixture (excess air)
a b
bsfc
Power
0.8 1.0 1.2
Excess-air Factor l
117. Effect of excess-air factor l on
exhaust emissions.
0.6 0.8 1.0 1.2 1.4
Excess-air factor l
NOx
HC
CO
118. Excess-air factor cont.
• The last two slides illustrate the effect of
the excess-air factor lon output, specific
fuel consumption and exhaust emissions.
• It should be noted that no single excess-
air factor can simultaneously generate
optimal response in all areas.
• Air factors ranging from l0.9…1.1 provide
the best results in actual practise.
119. Excess-air factor cont.
• Once the motor-cycle engine has reached its
normal operating temperature, it is essential that
l=1 be maintained to support subsequent
exhaust after treatment with a 3 way catalytic
converter (i.e. a rich mixture).
• The preconditions for satisfying this requirement
are precise determination of the induction air
quantity accompanied by an arrangement
capable of providing exact fuel metering.
120. Excess-air factor cont.
• To ensure a satisfactory combustion
process, precise fuel metering must be
accompanied by homogenous mixture
formation.
• The fuel must be thoroughly atomised.
• If this condition is not satisfied, large
droplets of fuel will form along the walls of
the inlet tract and port, leading to higher
HC emissions
121. Adapting to specific operating
conditions
• Certain operating states will cause the fuel
requirement to deviate considerably from that
required by a stationary engine at normal
operating temperature. The mixture must be
corrected accordingly.
• Cold starts
• Post-start phase
• Warm-up phase
• Part-throttle operation
• Full throttle operation
• Acceleration and high altitude adjustment
122. Cold starts
• During cold starts, the relative amount of fuel in
the mixture decreases, the mixture goes lean.
• Inadequate blending of fuel and air in the intake
mixture, low fuel vaporisation and condensation
on the walls of the intake tract due to the low
temperatures all contribute to this phenomenon.
• To compensate, and to assist the cold engine in
getting started, supplementary fuel must be
made available for starting.
123. Post-start phase
• After starts at low temperatures,
supplementary fuel must be provided to
enrich the mixture until the combustion
chamber heats up and the mixture
formation within the cylinder improves.
• The richer mixture also increases torque to
provide a smoother transition to the
desired fast idle speed.
124. Warm-up phase
• The starting and post-start phases are followed
by the engine’s warm-up phase.
• In this phase, the engine still requires a richer
mixture, as the cylinder walls are still cool, and a
portion of fuel continues to condense on them.
• Since the quality of mixture formation drops
along with falling temperatures (due to less
effective mixing of air and fuel, and large fuel
droplets), condensation forms in the manifold,
where it remains until it is vaporised as
temperatures increase,
125. Part-throttle operation
• During the part-throttle operation, priority
is assigned to adjusting the mixture for
minimum fuel consumption.
• The three way catalytic converters
required to meet stringent emissions limits
are making it increasingly important to
control the systems for l = 1.
126. Full-throttle operation
• When the throttle valve has opened to its
maximum aperture, the engine should
respond by providing its maximum
torque/output.
• This necessitates enrichening the air-fuel
mixture to l = 0.85…0.90
127. Acceleration
• When the throttle valve opens suddenly, the air-
fuel mixture responds by leaning out briefly.
• This is due to the fuel’s restricted vaporisation
potential at higher manifold vacuum levels (
there is an increased tendency to form fuel
layers on the intake-tract walls)
• To obtain good transition response, the mixture
must be enriched by an amount which varies
according to engine temperature.
• This enrichment provides good acceleration
response.
128. Trailing-throttle (overrun) operation
• The fuel-metering process can be
interrupted on trailing throttle to reduce
fuel consumption during descents and
under braking.
• Another advantage is the fact that no
harmful exhaust emissions are generated
in this operating mode
129. High-altitude adjustment
• Increases in altitude ( as encountered in
mountainous operation) are accompanied by a
reduction in air density.
• This means that the intake air being drawn into
the engine at high altitudes displays a lower
mass per unit of volume.
• A system which fails to adjust the mixture
accordingly will supply an excessively rich
mixture and the ultimate result will be higher fuel
consumption, increased exhaust gas emissions
and a significant fall of in power.
131. Ignition
• Function
• Requirements
– Igniting the mixture
– Generating the ignition spark
– High voltage generation and energy storage
– Ignition point/ ignition timing
– Ignition timing and exhaust emission
formation and control
132. Ignition ~ Function
• The function of the ignition is to initiate
combustion in the compressed air-fuel mixture
by igniting it at precisely the right instant.
• In the spark-ignition engine this function is
assumed by an electric spark in the form of a
short duration discharge arc between the
sparking plug electrodes.
• Consistently reliable ignition is a precondition for
efficient catalytic converter operation.
• Ignition miss will lead to damage to the catalyst
due to the overheating that occurs when
unburned combustion gases are burnt inside it.
133. Ignition requirements
• Igniting the mixture
– An electric arc with an energy content of
approximately 0.2mJ is required for
sustainable ignition in a stoichiometric air-fuel
mixture.
– Leaner and richer mixtures require up to 3
mJ.
– These figures represent only a fraction of the
total energy contained in the ignition spark,
the ignition energy.
134. Igniting the mixture cont.
• If the ignition energy is inadequate, there will be
no ignition.
• The mixture cannot ignite properly and the
engine will suffer ignition miss fire.
• For this reason, ignition energy must always be
supplied at levels sufficient to ensure that the
air-fuel mixture ignites even under the most
extreme conditions.
• A small ignitable mixture cloud passing by the
spark is enough to initiate the process
135. Igniting the mixture cont.
• The mixture cloud ignites and propagates combustion in
the rest of the mixture contained in the cylinder.
• A good mixture with unobstructed access to the ignition
spark will improve ignition characteristics, as will
extended spark durations and larger electrode gaps.
• The position and length of the spark are determined by
the dimensions of the sparking plug.
• The spark duration is governed by the type and design of
the ignition system as well as by the in cylinder
instantaneous ignition conditions.
136. Generating the spark
• Adequate high-voltage reserves must be present
before a spark can arc from one electrode to
another.
• When ignition is triggered, the voltage at the
electrodes climbs rapidly from zero until it
reaches the arcing voltage (ignition voltage).
• At the ignition point (firing point) the voltage at
the spark plug drops back to maintenance
voltage.
• The air-fuel mixture can ignite at any time for a
long as the arcing process is maintained (spark
duration).
137. Response curve for spark-plug voltage with
stationary or virtually stationary mixture
K=ignition voltage; s = burn voltage; T = spark duration
Voltage T
s
Approx.30 ms
K
0 1.0 2.0 3.0 ms
Time
0
10
kV
138. Generating the spark cont.
• Finally, the arc collapses and the voltage slowly
decays back to zero.
• High levels of turbulence in the mixture,
although in them selves desirable, can
extinguish the spark, leading to incomplete
combustion.
• For this reason the energy stored in the ignition
coil should be sufficient for sustaining one or
according to requirements several successive
sparks
139. High-voltage generation and
energy storage
• On battery-powered systems, an ignition coil is
generally employed as a step-up transformer to
generate the high-voltage required for spark
ignition.
• On coil ignition systems it also serves a second
important function by storing energy.
• The ignition coil is designed to provide high-
voltage reserves extending well beyond the
spark-plugs’ maximum potential demands.
• It supplies voltage at levels of 25..30 kV with
stored energy in the coil of 60..120 mJ
140. Ignition point (firing point) and
ignition timing
• Approximately two milliseconds elapse between
the instant when the mixture ignites and
complete combustion.
• Provided that the mixture strength does not vary,
this period will remain constant.
• The ignition spark must thus arc early enough to
provide optimal combustion pressure under all
engine operating conditions.
• The standard practice is to describe the ignition
timing relative to top dead centre, or TDC at the
crankshaft
141. Ignition point (firing point) and
ignition timing
• The ignition timing is specified in “ degrees
before TDC” or as ignition advance angle.
• Adjusting the ignition timing toward TDC is
called retarding the ignition ( or reducing
the amount of advance) whilst
displacement in the opposite direction is
referred to advancing the ignition
142. Ignition timing selection criteria
• Maximum engine output
• Modest fuel consumption
• Avoidance of engine knock
• Minimal tail pipe harmful gaseous emissions
• Unfortunately these demands are mutually
antagonistic.
• Compromises have to be made on a case by
case basis.
• The most appropriate ignition timing for any
individual condition will depend upon a number
of factors
144. Basic adjustments to timing
• The basic adjustments necessary to adapt the ignition
timing to the momentary engine conditions are
performed by engine speed and load sensitive devices.
• The high compression ratios favoured in to days
motorcycle engines considerably increase the danger of
knocking beyond that encountered just 5 years ago.
• Engine knock is produced by spontaneous combustion in
portions of the mixture that the flame front emanating
from the ignition spark fails to reach during the initial
flame propagation phase.
• This condition corresponds to excessive ignition advance
145. Combustion Knock
• Combustion knock leads to higher
combustion-chamber temperatures, which
can cause pre-ignition from hot spots.
• It also results in radical pressure
increases.
• The sudden combustion generates
pressure fluctuations, these are
superimposed on the normal pressure
pattern.
147. Two types of “Knocking”
• Acceleration knock under high load, low engine
speed. (Audible knock and or pinking)
• High-speed knock as encountered at high
engine rpm during operation at high load (At or
near WOT)
• High speed knock is critical for the engine.
• It is inaudible due to the general level of engine
noise, Thus audible knock is a poor source of
feed back.
148. Knock study
• Continued knock causes substantial damage to
the engine.
– Destruction of the cylinder head gasket
– Bearing damage
– Holes in pistons
– Damage to sparking plugs
• Pre-ignition depends upon many factors
– Engine design
• Combustion-chamber design
• Homogeneous air fuel mixture
– Fuel quality and ignition timing
149. Effect of excess-air factor l and ignition timing on
brake fuel consumption
20°
30°
40°
50°
Ign.°
0.8 1.0 1.2 1.4 l
340
420
500
580
660
Specific
Fuel
Consumption
150. Ignition timing and HC exhaust
emissions
• Initially, specific fuel
consumption drops in
response to increases in
the excess-air factor.
• It starts to rise again from
l=1.1…1.2 onward.
• As the excess-air factor
increases, so doesa the
optimum ignition advance
angle.
50°
40°
30°
20°
0.8 1.0 1.2 1.4
HC Emissions
HC
151. Effect of land ignition timing on
NOx emissions
• NOx rises in response to
higher oxygen
concentrations and higher
peak combustion
temperatures.
• The result is a bell
shaped curve
• This curve explains the
considerable influence
ignition timing has upon
NOX formation
50°
40°
30°
20°
0.8 1.0 1.2 1.4
Excess-air factor l
20
10
NOx
g/kWh
152. Ignition Timing
• The relationship between specific fuel
consumption and the excess-air factor
(assuming optimum ignition timing) is
explained as follows:
– The air deficiency encountered in the fuel-rich
range leads to incomplete combustion, while
delayed combustion and combustion miss
occur as the operating limit is approached in
the lean range, resulting in high BSFC
153. To conclude
• Attempts to comply with emissions limits by
operating the engine in the l= 1.2…1.4 range
place substantially greater demands upon the
ignition timing.
• Because the 3 way catalytic converter requires
mixture control to l=1 to function properly, the
ignition advance angle is the only optimising
criterion that remains available with this kind of
emissions-control strategy
155. Engine management system over-
view Inputs
• Ignition on/off
• Vehicle speed
• Battery voltage
• Intake air temperature
• Throttle angle
• Knock sensor
• Barometric pressure
• Relative humidity
• Camshaft position
• Gear selection
• Engine temperature
• Air quantity
• Lambda oxygen
sensor
• Engine rpm
• Rate of throttle
change
156. Auxiliary functions
• Addition open and closed loop control functions-
required in response to legislation aimed at the
reduction in exhaust emissions and fuel
consumption.
– Idle speed control
– Lambda oxygen control
– Control of evaporative emissions
– Knock control
– EGR ~ for reducing NOx emissions
– Control of secondary air injection to reduce HC
emissions
157. New additions
• Open-loop turbocharger control
• Variable tract intake manifold
• Camshaft control for achieving reductions
on exhaust emissions and enhanced
power output
• Knock control and engine and vehicle
high-speed governing functions to protect
engine and rider !
158. The Sparking Plug
Working environment
Reliable operation for at least 30 million cycles·
Normal operating temperature between 350°C and 900°C with a
possible temperature delta between these extremes in less than 4 seconds
Between 14 and 25 kV electrical stress
When running at 6,000 rev/min ( every 20mSec) near instantaneous
pressure change from negative to 1,000 psi (6.9 x106 Pa)
Corrosive environment including Sulphur, Bromine,Phoshorus etc.
Needs abrasion resistance from high velocity particles
159. The working environment
• The heat generated by the combustion of petrol and air
in a modern engine can result in temperatures of more
than 2,500°C inside the combustion chamber, while
outside the engine, at the terminal end of the plug, the
air temperature can be sub-zero in winter.
160. 2,500 °C would melt all the metal around it if the flame heat
were continuous. The flame however, lasts for only one
stroke of the engine. At idle, 600 rev/min it lasts for only
0.05 seconds, and at 6,000 rev/min for 0.005 seconds. In
the four-stroke engine there are three strokes with out
flame (induction, compression and exhaust) for each
power stroke, during which the heat generated in the
power stroke is conducted to the cooling system via the
engine walls.
The working environment
161. • The new generation of 42 volt ignition systems have
given rise to high kV discharge plugs, new detergent
additives have been added to fuels, various methane
and hydrogen based gaseous fuels are being utilised
which require higher kV spark discharge and the spark
plug is being design to last for the life of the power unit.
• A truly daunting task for the spark plug designer and
development engineer.
The working environment
162. Design problems
• The spark plug serves the function of conducting high
tension current into the combustion chamber to provide
ignition of the fuel air mixture. Sealing is a major
problem, and this is undertaken by the composite
metal/glass conducting seal inside the insulator and by
the metal gasket between the insulator and the mild steel
shell. These seals pay an important role in the
performance of the plug in addition to sealing gas
pressures. They provide the main paths by which the
heat may transfer into the bulk of the cylinder head from
the spark plug components.
163.
164. What stops it melting ?
• The heat generated at the firing end (tip) of the sparking
plug when the fuel air mixture is ignited is dissipated in
the engine by conduction via the ceramic insulator nose
and the central electrode and the mild steel shell.
166. Heat transfer
• The metal components of the construction transfer heat
more rapidly than the ceramic insulator, the relevant
thermal conductivities differing by approximately a factor
of two. If the heat is not efficiently removed, with the
subsequent firings the ceramic tip (the ‘nose’) of the
spark plug soon attains a temperature at which it is able
to pre-ignite the fuel/air mixture before full compression
is achieved sand prior to the timed electrical discharge
taking place. This pre-ignition results n a drastic loss of
power and increased levels of gaseous emissions and if
allowed to continue, the increasing retention of heat can
lead to permanent damage of spark plug, piston, cylinder
head and catalytic converter formulation.
167. • It is this ability of the spark plug to remove heat from its
firing end determines its suitability for a particular type of
engine (heat range) It is evident that a standard
quantitive measurement of this ability is desirable to
relate one plug to another in the range of designs in
existence and to correlate the products of different
manufactures. The current method exclusively used in
the industry is known as the ‘Pre-ignition’ rating of spark
plugs
Heat transfer
168. Sparking plug ratings
• The method used for ascertaining a spark plug rating is
to use a single cylinder 4-stroke engine whose essential
nature is constant speed running with changes in power
brought about by supercharging. Supercharging is when
air or the air/fuel mixture is presented to the cylinder at a
pressure that is higher than atmospheric pressure.
Because of this higher pressure, the air supplied to the
cylinder has a higher density and is able to absorb more
fuel vapour. This increases the power output.
169. Running a sparkplug rating test
• For a given plug installed in a rating engine, by gradually
increasing the amount of supercharging and adjusting
the fuel mixture strength to give optimum temperature at
each setting, the plug experiences higher and higher
temperatures until it begins to run into re-ignition
(indicated by rapid rise in the measured plug
temperature) As Pre-ignition occurs, the fuel supply is
instantly cut off preventing uncontrolled temperature rise
and possible damage to the engine.
170. Running a sparkplug rating test (cont)
• When stable operation is obtained 34 millibar of
supercharge boost below the pre-ignition point for three
minutes, the torque is measured, allowing an IMEP value
to be calculated according to equation 4 above. At any
fixed set of engine conditions there is a definite boost -
IMEP relationship which is a straight-line function.
172. Hot and Cold Plugs
• Various IMEP values are required because of the very
different demands on engine performance. A racing car
for example, needs to run at high temperatures for
maximum efficiency and power output over a relatively
long period, The best spark plug for this environment
would be one which could dissipate heat rapidly to the
engine mass. For a ‘HOT’ engine therefore, a plug that
remains as cold as is necessary to prevent Pre-ignition –
a COLD- plug is required.
173.
174. • Its IMEP value would be relatively high. However, if the
same plug was used on a family saloon car used on
short urban journeys, and which as a result never fully
warms up, combustion deposits would soon build up
leading to misfiring. In this situation what is required is a
plug with a relatively low IMEP value which does not
dissipate the heat so readily and whose operating
temperature will be sufficiently high to burn off the
combustion deposits. Thus a COLDER engine calls for a
HOT plug. Other terms that are used are HARD = COLD
or SOFT = HOT
Hot and Cold Plugs
175.
176. Hot and cold sparking plugs
• The much shorter heat path of the cold plug can,
however, cause problems in that there is much less area
of the ceramic insulator exposed to the cylinder. Under
certain engine conditions such as cold start with full
enrichment, carbon combustion deposits build up on the
nose of the plug, offering a leakage path for the current
to earth and leading rapidly to a situation wherein the
plug ceases to function, known as cold fouling
177. • Substitution by a normal plug of lower IMEP rating, thus
providing a longer nose to overcome this problem, may
be unsatisfactory due to the reduction in maximum safe
operating temperature. The plug designer and the
engine development engineer have however, one or two
options available to satisfy the provision of a greater
surface area of the insulator nose whilst maintaining the
IMEP rating.
Hot and cold sparking plugs
178. Design advances
• Recent years have seen the adoption of centre electrodes
containing a core of copper. These electrodes are more thermally
conductive than the normal nickel-alloy types and enable a longer
electrode and ceramic nose to be employed. This solution elegantly
achieves the aims discussed above. I.e. larger surface area for the
same heat rating. An alternative means of increasing heat removal
rate is to eliminate the ‘air gap’ between the ceramic nose and the
centre electrode by filling the space with a refractory cement
material. This is normally achieved by the application of a vacuum to
the tip of the plug and allowing the re-establishment of atmospheric
pressure to force the cement into the evacuated space.
179. Heat conduction
• Air can be a very effective thermal insulator and its replacement by
the solid cement enables the heat to transfer from the ceramic
considerably more efficiently by conduction into the centre electrode
along its entire length and hence be more readily dissipated.
• Since most of the heat conduction takes place by way of the
electrodes, the use of materials more efficient in this respect must
obviously be considered. However, the employment of, say nickel in
place of nickel-alloy increases heat dissipation, and hence IMEP, but
at the expense of electrode durability. This is due to more rapid
chemical, electrical and mechanical erosion of the softer material,
despite its higher temperature tolerance.
181. • One problem that the designer has to be aware of in producing a
very cold plug is a possible change in the site from which pre-
ignition may occur. Normally, initiation of pre-ignition will take place
from the overheated ceramic nose which is unable to dissipate the
heat rapidly enough, provided there are no incandescent sharp burrs
or a glowing protrusion of combustion deposits present to pre-empt
such occurrence. As the IMEP value is increased, the removal of
heat from the nose becomes more efficient, lessens the chance of
the ceramic overheating and the emphasis shifts to the side
electrode which then becomes the prime site for pre-ignition. The
plug is then said to ‘rate’ off the side wire instead of the nose.
Attempts to control this phenomenon centre on improving heat
removal rate of the side electrode either by a change of material, as
discussed above, or by cutting back the side wire to provide a
shorter path.
Heat conduction
182. Long life – 160,000 km
• Changes in Spark plugs have been caused by demands
for longer life and also improved ignitability in today's
lean burning modern engines. It is critical that each
cylinder fires to prevent unburnt fuel from reaching the
catalytic converter and causing damage. Variations in
burn rates on a cycle to cycle basis are critical when new
emission regulations are reviewed, a few parts in one
million of trace emission gases can be difference
between a regulatory pass or fail.
183. Noble metals
• With engine manufacturers striving to lean off engines to
improve fuel consumption the possibility of misfire
becomes a problem, in addition manufactures are
striving to produce an engine where the sparking plugs
will never need changing. A very high voltage with very
large gaps appears to be the answer.
It has been proven that a very thin electrode will improve
ignitability, however a thin electrode made from nickel
would quickly erode and fail, therefore spark plug
manufacturers have necessarily turned to precious
metals to withstand the harsh environment. This has
lead to the introduction of precious metals to withstand
the harsh environment.
184. Noble metals
• The introduction of precious metals like platinum and
iridium gave spark plugs the added benefit of long life. It
is important to note that spark plugs have historically
been regarded as consumable with a limited service life
and as such requiring to be changed at regular intervals.
NGK Spark Plugs designed and Patented V-Groove
Spark Plugs for improving ignitability in nickel alloy
electrodes. This style of spark plug incorporates a 90-
degree V Groove in the centre electrode and ensures
that sparking occurs at the periphery of the electrode,
thus enhancing
ignitability.
185. 42 Volt
• The introduction of 42 volt ignition systems means that
even higher spark plug voltages can be applied leading
to larger plug gaps (up to 3mm) which have very long
lives indeed.
186. R.F.I.
• All modern engines require the use of resistor type spark
plugs. A resistor type spark plug is one that incorporates
a 5 K ohm resistor to suppress ignition noise generated
during sparking. (Radio frequency interference). Radio
frequency interference is commonly exhibited by the
crackle sound coming from the car radio and there are
now international standards covering R.F.I., which is
considered a type of pollution.
187. R.F.I.
• As R.F.I. can also cause premature failure to other
electronic components in a modern vehicle, for example
the ECU it is important that resistor spark plugs are used
to prevent this possibility. As stated earlier, the use of
precious metals in spark plugs has increased their
service life. The use of Iridium spark plugs is only just
starting with Japanese car manufacturers who are
finding them ideal for very low emission engines.
188. Electrode temperatures
• We have discussed heat range selection; it is vital to
ensure optimum performance of spark plugs. A spark
plug's optimum operating temperature is between 450
degrees C and 870 degrees C. Spark plug tip
temperatures outside this range can occur when an
incorrect heat rating is selected. Viz to re-cap:
189. When the heat rating is too high
• The spark plug temperature remains too low and causes
deposits to build up on the firing end; the deposits offer
an electrical leakage path that gives rise to loss of
sparks.
190. When the heat rating is too low
• The spark plug temperature rises too high and induces
abnormal combustion (pre-ignition): this leads to melting
of the spark plug electrodes as well as piston seizure
and erosion. Many plug manufacturers have pioneered
the use of a copper cored electrode NGK being the first
in 1958, which enables a spark plug to heat up quickly
and also dissipate heat quickly giving an ultra wide heat
range. It is essential to use a spark plug that fits a
specific engine and its conditions of use
192. Use your eyes and nose !
• It is important to observe spark plugs that have removed from
engines and learn from the visual evidence. Oxidization, metal
deposits on the ceramic, copper migration from gaskets all tell a
story.
• When this data is reviewed along side rate of cylinder pressure rise
against crankshaft angle (combustion analysis) and a measurement
of the gaseous and particulate emissions then the development
engineer has a very good tool.
• To date, the sparking plug has been used only in gasoline, or gas
based fuels.
• New emissions regulations, may force diesel engines to control the
point of burn initiation by utilising sparking plugs.
194. Motorcycle engines
• Almost all commercially available motorcycles
are driven by conventional, gasoline fuelled
internal combustion engines.
• Some small scooter-type machines use electric
motors.
• Suzuki and Norton once produced gasoline
fuelled engines with Wankel rotary power units.
• There are Diesel and indeed air powered units
195.
196. Definition
• Displacement is defined as the total volume of air/fuel
mixture an engine can draw in during one complete
engine cycle. In a piston engine, this is the volume that is
swept as the pistons are moved from top dead centre to
bottom dead centre. To the lay person this is the "size" of
the engine. Motorcycle engines range from less than 50
cc (cubic centimetres), commonly found in many mopeds
and small scooters, to a 6000 cc engine used by “Boss
Hoss” in its cruiser style motorcycle BHC-3 LS2. Many
state laws in the US define a motorcycle as having an
engine larger than 50cc, and a moped as a vehicle with
an engine smaller than 60cc.
197. Twin cylinder applications
• Two-cylinder motorcycles are
called "twins." The three most
common arrangements are
• The “V-Twin" where the cylinders
form a "V" around the crankshaft,
which is oriented transversely (i.e.,
perpendicular to the direction of
travel). Narrow angle V twins
vibrate.
• Common especially in classic
British motorcycles and Japanese
motorcycles, is the inline twin or
known as a parallel twin when the
cylinders share a common crank
pin. In this design the cylinders
are side by side vertically above
the crankcase. If not vertical they
are generally nearly so in order to
maximize airflow cooling.
•The opposed twin in which the
cylinders protrude sideways into
the cooling air stream. (BMW)
198. The Boxer Motorcycle Engine:
• The term "Boxer" refers to an engine style where
a pair of cylinders are horizontally opposed to
each other -- if you look at the two cylinders from
the top, they're almost on the same line, on
either side of the engine. When they fire, they do
so on opposite strokes, but both cylinders move
in towards the crankshaft and out away from the
crankshaft at the same time. The result, at least
in theory, is a vibration less engine. What will be
the reaction if the engine misfires and stalls out.
199. Boxer Two Cylinder Motorcycle
Engines:
• An early design to compete against the V-Twin engine.
Designed to offer competitive power and reduced
vibration.
• The designed worked and was a success in both North
America and Europe with the design almost taking over
during the Second World War.
• The Two-Cylinder Boxer Twin engine offers a much
improved level of smoothness over the 45o V-Twin and
Parallel Twin engines and a compromise between them
both in terms of higher RPM and less torque.
• The disadvantages is both cylinder heads stick out at
either side of the engine, making less cornering distance
and are much more susceptible to damage.
200. Boxer twin
• While the Boxer twin
engine was a good
design in day (1960),
BMW has taken the
design a step further
today and is now
much improved in
RPM range and can
be found in their new
sport bikes along with
the In-line four.
201. Boxer twin
• You can still find
motorcycles today using
the Boxer Twin engine
around the world such as
the 2003 BMW R1150R.
BMW was the biggest
user of the Boxer Twin
engine design, even
Harley-Davidson used it
during the Second World
War. Unfortunately for the
Boxer Twin, the design is
still not used very much
compared to the In-Line
and V-Twin designs
202. In-Line Parallel Twin Motorcycle
Engines:
• 1973 Yamaha TX500B 1989 Kawasaki Ninja 250 n-Line Parallel
Twin motorcycle engines are two cylinder designs running parallel to
each other in separate chambers either in 180o (one up, one down)
or 360o (both up, both down) configurations.
• Today, the Parallel Twin engine isn't as popular as it once was, but it
produces torque like a single, is light in weight and produce almost
double the RPM and have good horsepower and top speed as well.
• Bikes that use them today (GS500E, CB400/500, Ninja 250/500)
choose this design for its inherent advantages to a light, fast and
nimble style bike. Since they have almost twice as many
components as a single and use a double barrel carbburetor
maintenance is higher but not as high as other In-line engines.
Thanks to having two pistons and with the use of counter balancers
to counter the effect of piston forces parallel twin engines are much
more smooth than Singles.
• The disadvantages of the In-line Parallel twin is more vibration,
lower RPM and lower horsepower than other In-line engines.
203. V twin designs
•The angle in the V-twins varies
from around 45 degrees to 90
degrees. Typical of the former are
the Harley-Davidson and Vincent
engines which due to their firing
order tend to vibrate more. Ducati
and Moto Guzzi make V-twins with
cylinders arranged at a 90 degree
angle to quell primary vibrations.
Some Moto Guzzi motorcycles
have V-twins oriented transversely:
one cylinder to the left, one to the
right.
204. V Twin design advantages
• Technology Benefit:
• By virtue of the fact the
camshafts extend
perpendicular to the axis of the
crankshaft, the camshaft drive
mechanisms can be wholly
accommodated within the V
space defined by the cylinder
blocks.
• The inlet and exhaust ducts
may therefore be provided on
the front and rear of the block
and may be designed solely
with efficiency and power
considerations in mind.
205. Twin cylinder engines
• The parallel twin engine configuration was made famous by Edward
Turner’s Triumph Speed Twin design as used on the Triumph
Bonneville
• In the famous BMW flat twin ("boxer twin") engine, and used as well
now by the Ural and historically by the Douglas power unit where
the cylinders are horizontally opposed, protruding from either side of
the frame.
• The boxer is the only twin-cylinder arrangement that has inherent
primary balance without a rocking couple, producing very low
vibration levels without the use of counterbalance shafts.
• Sunbeam, produced an air cooled inline twin with a drive line prop-
shaft.
• Narrow-angle V-twin engines dominate the cruiser motorcycle
segment.
207. • Displacement:
80 cubic inches/1340cc
Compression ratio:
10.3:1
Carburettors:
2X38mm flat-slide Mikuni
Pistons:
Keith Black flat top (8.5:1
in a stock 80 inch Harley)
• Ducati cylinder heads
209. V designs
• A well developed very early 1900's engine design to
allow two cylinders to occupy the narrow bicycle shaped
frame of the time and to control width.
• The idea was a good one, and was well accepted as the
years progressed.
• You can find the V-Twin (V-Twin) motorcycle engines in a
variety of motorcycles today with most of them being in
the cruiser style.
• V Twin engines are designed in different amounts of
degrees (measured from the middle of each piston to
piston), the further apart the angle is, the smoother than
engine becomes without loosing and advantages over
the narrower V Twin designs.
• Naturally, as the angle increases the V-Twin gets longer
(and larger) in size (but not in width).
210. V Twin power units
• The V-Twin engine has many
advantages such as:
• Low weight, simplicity, high
torque, and able to provide a
good RPM range.
• The V-Twin also has a few
disadvantages as well such as:
Low horsepower and top
speed compared to 3+ multi-
cylinder engines, and
depending on the V angle can
have a high vibration.
• 90 degree Vs are inherently
well balanced meaning they
vibrate far less than other v
angles or parallel Twins.
212. In line Triple cylinder
• In-Line Triple Cylinder engines are getting harder to find in today's
motorcycles.
• An older design to minimize the disadvantages of both the Parallel
Twin and the In-Line Four in one package.
• Trident Motorcycle Corporation is almost the last manufacturer still
using this style of engine in their new motorcycles (Speed Triple).
• The advantages of Inline Triples are:
– They are able to produce much higher RPM and take advantage of still
having more torque than the In-Line four design.
– Weigh less than the In-Line four and use less moving parts as well. As
well as suffering less vibration because the pistons can be more easily
balanced.
• Savings on maintenance is marginal verses the In-Line four, while
parts are more expensive due to the "rarity" of the engine style.
While they may not be as smooth or offer as much torque as inline
twin/four design, they are a good compromise for what they do well.
213. In line Triple cylinder
• Three-cylinder designs are unusual — they are referred to as
"triples" and are normally in line in layout.
• The British Hinckley built Triumph and Italian Benellias well as
Japanese Yamaha are three motorcycle manufacturers who have
used triples in their large displacement motorcycles.
• The Italian firm Laverda was also renowned for their 1000cc and
1200cc triples.
• On the other hand, in the two-stroke world, triples were more
common.
• In the 1970s Kawasaki had its 250, 350, 500, and 750 triples which
were known for their power (but maybe not ride-ability) and Suzuki
had 380, 550, and 750 triples of which the last one was water cooled
and thus gained the nickname "Water Buffalo" or "Kettle".
• All the others were air cooled. Honda also produced a water cooled
V-3 two-stroke.
216. 4 Cylinder engines
• Four-cylinder engines are colloquially known as "four-bangers."
• They are quite similar to car engines, and most commonly have a
transverse-mounted in-line four layout, although some are
longitudinal (as in the earlier BMW K series). V-4 and boxer designs
(as in the Honda Gold Wing series) have been produced.
• One of the more unusual designs was the Ariel square four,
effectively two parallel-twin engines one in front of the other in a
common crankcase - it had remarkably little vibration due to the
contra-rotating crankshafts.
• Yamaha and Suzuki used the same concept in their water-cooled
two-stroke engines (RZ500 and RG500 respectively).
• Since the advent of Honda's CB750 straight-four engine, straight-
fours have dominated the non-cruiser street motorcycle segments.
219. 2000 Kawasaki ZRX1200 In-Line 4
• Today's speed king engine for
top horsepower, smoothness
and top speed.
• Many bikes offer this engine
because of those features like
the ZX1200R, CB900F,
GSXR750.
• The In-Line Four was
introduced in 1968 on the
Honda CB750 and no other
engine could match it at the
time on the drag strip. Mostly
found in the larger (500cc)
sized capacities due to there
complexity and size of pistons
required.
220. 4 Cylinder units
• The disadvantages of this
style are weight,
complexity, lack of torque
at lower RPM ranges.
• Since most in-line four
engines use a bank of
four carburettors
maintenance costs are
near the highest for the
in-line engines.
• Smoothness while very
good is not as good as
the boxer style of
engines.
221. V 4
• An advancement on the V-
Twin design to remove the
inherent disadvantages such
as vibration, top speed and
horsepower.
• Today, you can find the V-Four
engine in power cruisers,
muscle bikes and touring bikes
(like the Vmax, Magna,
Venture) where large capacity
(750cc+).
The V-Four is a newly developed
(early 1980's) engine and offered
advantages of its own such as
smoother ride, more torque and
horsepower, and less complexity and
width than the In-Line 4/6 and boxer
engines.
222. Boxer Four Cylinder Motorcycle
Engine:
• Since the late 1950's, the Boxer Four was the successor to the
Boxer Twin in teams of performance and more enhanced
smoothness.
• With 2 cylinders opposed on either side of the engine the design is a
much more suited to touring than sport (due to its cornering limits)
but is used for both. The Boxer Four offers much of the advantages
as an In-Line for but sacrifices higher RPM and narrowness of
design for smoothness. Many manufacturers today (even the
biggest boxer engine user BMW) are switching away from the Boxer
Four engine in favour of the Inline-Four (even for touring).
• More complex, harder to find aftermarket parts and expensive to
maintain, their popularity is dwindling.
• Mostly found on BMW motorcycles and Honda Goldwing touring
motorcycles but harder to find on new motorcycles today. The Boxer
Twin has again taken the number one spot over the Boxer Four for
BMW.
223. Five Cylinder
• Honda has produced a five-cylinder
engine for racing, the RCV, but no five-
cylinders exist for commercial production
motorcycles.
224. Six Cylinder
• Six cylinder engines are uncommon, and
usually found only on the biggest
motorcycles. Two of the best six cylinder
examples are the Honda CBX and the .
Nowadays the most famous six cylinder
engine is the boxer used on the Honda
Valkyrie series and the Honda Gold Wing.
226. In line six
• A highly complex engine produced mainly in the late 70's
and early 80's.
• The In-line Six was designed both in a horsepower, size
and multi-cylinder war to be the king of all engines.
• Found only in the largest (1000cc+) motorcycles (such
as the Z1300, CBX1000) and offering more top end
speed, horsepower and smoothness than the in-line
fours.
• The disadvantages unfortunately mostly outweighed the
advantages:
– Too many moving parts, too complex for its time, too expensive to
maintain, too heavy.
– While carburettors were two carbs in a bank and a set of 3 (instead of 6
individual carburettors) they were still very hard to maintain properly.
– Unfortunately, the market was never ready for such a complex engine at
the time.
229. Honda Boxer 6
• With Honda's quest to provide the consumer with ultimate
smoothness we now have the Boxer Six.
• It would seem history has repeated itself with the introduction of
another 6 cylinder engine 20 years ago (see Honda Inline-Six) and
the high level of complexity is still there in this engine.
• Like the Inline Six, this engine is aimed at the Touring market (and
power cruisers as well), will the consumer be ready for it? So far
after 4 years of production, it seems it is.
• Currently the only manufacturer offering this engine is Honda. So
parts are expensive as well as maintenance and up keep, it is also
very heavy. But for super long distance touring, you cannot find a
more smooth engine on the market.
• The advantages of the Boxer Six are many, high amounts of torque
and horsepower, good RPM range and glass like smoothness. They
are only made in VERY large sizes (1500cc) right now.
230. Big Baa Lambs
• More than six cylinders
• A number of custom and one-off motorcycles
use more than six cylinders.
• For example, the Boss Hoss motorcycle uses a
Chevy V-8 motor. But no major motorcycle
manufacturer uses more than six cylinders.
• In the mid 90's Daimler-Chrysler manufactured a
limited number of Tomahawk concept bikes
featuring a Dodge Viper's V-10 engine.
231. Large engines
• Galbusera built their V8 in 1938, and Moto Guzzi
experimented over a period of two years with their dual
overhead cam 500cc V8 (Otto Cylindri) in the 1950's.
• A number of custom and one-off motorcycles use more
than six cylinders. For example, the Boss Hoss
motorcycle uses a Chevy V-8 motor(5700 and 6000 cc).
• In the mid 90's Daimler-Chrysler manufactured a limited
number of Tomahawk concept bikes featuring a Dodge
Viper's V-10 engine.
• Australian company Drysdale have built short runs of
750cc V8 superbikes and 1L V8 road going motorcycles,
both with engines specifically developed for the purpose.
But no major motorcycle manufacturer uses more than
six cylinders.
232. BMW V12
5.5 litre BMW V12
Dragster.
HMS Sport bikes, over in
Germany, has been
working on this project,
taking the engine from a
BMW 750i and creating
something a little more
sporting.
They say it will have twin
turbos and NOx but it
looks to be a bit short of
completion at this point.
233. Diesel
• There are also motorcycles with diesel engines.
In November 2006, the Dutch company E.V.A.
Products BV Holland announced that the first
commercially available diesel powered
motorcycle, its Track T-800CDI, achieved
production status The Track T-800CDI uses a
800 cc three-cylinder Daimler Chrysler diesel
engine.
• However, other manufacturers, including Royal
Enfield, had been producing diesel-powered
bikes since at least 1965 with production in
India.
235. Four stroke vs. Two stroke
• As applied to motorcycles, two stroke engines have some
advantages over equivalent four-strokes: they are lighter,
mechanically much simpler, and produce more power when
operating at their best.
• But four-strokes are cleaner, more reliable, and deliver power over a
much broader range of engine speeds.
• They use the Otto Cycle: Induction-Compression-Power-Exhaust.
• In developed countries, large two-stroke road-bikes are rare,
because - in addition to the reasons above - modifying them to meet
contemporary emissions standards is prohibitively expensive.
• Almost all modern two-strokes are single-cylinder, air-cooled, and
under 600 cc.
• In Europe there are a lot of water cooled 125 cc two-strokes and off
road motorcycles that are also two-strokes with water-cooling.
236. Two-Stroke Motorcycle Engines:
• In a Two-Stroke engine the piston goes down,
compressing the fuel mixture under the piston and
blowing it into the cylinder. As this mixture blows in it also
blows the burnt exhaust gases out. The fuel mixture is
blown into the cylinder through passages ( Ports ) in the
cylinder walls. The piston comes up, covering the ports
in the cylinder walls and compressing or squeezing the
mixture. This also creates a vacuum in the crankcase
under the piston, sucking the fuel mixture into the
crankcase. The spark then ignites the mixture and the
burning gases push the piston down, starting everything
again.
This is all done in two strokes of the piston.
Piston down... Piston up.
Two-Strokes.
237. Two stroke disadvantages
• Powerful with lots of torque,
inexpensive to manufacturer,
high RPM's and light in weight
for its little size they were
popular in sport bikes and dirt
bikes till 1985.
• Their one major disadvantage,
pollution, killed them over the
four-strokes since both oil and
gas are burned at the same
time to make the motorcycle
engine run.
• Today they are obsolete, hard
to maintain and expensive to
repair.
239. Two stroke or four stroke
• As applied to motorcycles, two stroke engines have some
advantages over equivalent four-strokes: they are lighter,
mechanically much simpler ( cheaper to build and rebuild), easier to
cold start, and produce twice the power for a lesser weight (due to
the doubled power-stroke), when operating at their best.
• In the USA, two-stroke road-bikes are rare, because modifying
them to meet contemporary emissions standards has been
prohibitively expensive -- although this is debatable. Envirofit has
developed a retrofit direct injection system for existing 125cc
engines.
• Stock four-strokes are cleaner then carburetted two-strokes;
provided the four-stroke hasn't worn to the point where it starts
'burning oil' (e.g. carter oil entering the combustion chamber, either
from leaking valves, head gasket, cylinder-wall/piston or a
combination thereof). Rotax powered snowmobile, some Auto-
rickshaw/TukTuk and most scooter engines utilize air-assisted direct
injection. Some four-strokes are more reliable as their engine
revolutions can be kept comparatively low.
240. Two stroke or four stroke
• A four-stroke power band has a wider range than a two-stroke,
making such machines easier to control. However modern two-
stroke engines, or at-least those powering dirt bikes, have some
form of exhaust power-value system providing a similar power band
range ( Torque curve).
• Almost all modern two-stroke bikes are single-cylinder, water-
cooled, and under 500cc. In Europe there are a lot of 125cc two-
stroke street bikes and 125cc or 250cc off-road motorcycles.
• Also most mopeds and some scooters have 50cc two-strokes
engines, often bored to 60-80cc with widely available kits emission
problems arise typically with mismatching of air-filter (mainly on
models without reed-valve intake), and/or exhaust back-pressure to
engine, causing unburned pre-mix full to escape to atmosphere.
Aftermarket sports parts tend to make machines rather noisy, not
helping the image the general public has of two-stroke motors.
241. Cooling
• Water-cooled motorcycles have a radiator (exactly like the radiator
on a car) which is the primary way their heat is dispersed. Coolant is
constantly circulated between this radiator and the cylinders when
the engine is running.
• The radiator has a small fan attached to it which is controlled by a
thermostat. The cooling effect of this fan is enough to prevent the
engine overheating in most conditions, so water-cooled bikes are
safe to use in a city, where traffic may frequently be at a standstill.
•
• Emissions regulations and the market demand for maximum power
are driving the motorcycle industry to water-cooling for most
motorcycles.
• Even Harley Davidson, a strong advocate of air-cooled motors, has
begun producing a Revolution water-cooled engine.]
242. Air cooling
• Air-cooled motorcycles have no "cooling
system," as such. As air blows past the engine
case, it disperses heat.
• The cylinders on these bikes are designed with
heat sinks (fins) to aid in this process.
• Air cooled bikes are cheaper, simpler and lighter
than their water-cooled counterparts, but unless
the ambient temperature is cold, they may
overheat if the bike stands still, as in traffic.
• Some applications have air cooled cylinders
and water cooled cylinder heads.
243. Hybrid cooling
• Some manufacturers use a hybrid cooling
method where engine oil is circulated
between the engine case and a small
radiator.
• Here the oil doubles as cooling liquid,
prompting the name "oil-cooling."
• Suzuki has produced many "oil-cooled"
motorcycles.
244. Motorcycle Cooling System Design
• A motorcycle cooling system is designed to keep the
engine coolant temperature at a specific operating point,
usually 180°F, when moving at speed on a hot day (90°F
air is usually used in the calculations).
• This is the operating condition that is used to size the
radiator, water pump and hoses.
• The overall design is based on the expected and
recommended 50/50 mixture of ethylene glycol and
distilled water.
• If you use any other coolant or mixture percentage you
change the operating temperature
245. CFD
• To develop an air-cooled engine, cooling air flow was studied by
CFD.
• Cooling performance of engine is necessary for precise temperature
control. However, it is difficult to obtain the stable radiation for
motorcycles because of the effects of unsteady driving wind.
• Cooling fins are thin and complicated; therefore plenty of work time
is necessary to create a boundary fitted mesh for each object shape.
• In addition, since low Reynolds (Re) number areas exist with high
Re number areas in a calculation domain, applications of the wall
function are limited. Therefore, the Partial Cells in Cartesian
coordinate method was developed, which expresses complex
shapes according to turbulence boundary conditions in the
Cartesian coordinate.
• Furthermore, local heat transfer coefficients are calculated by
Karman's analogy.
246. Coolant
• The optimum coolant combination is a 50/50 mixture of antifreeze
and water.
• Any greater concentration of antifreeze does not significantly
increase the efficiency of the coolant.
• Actually, the more antifreeze you add above 50 percent, the lower
your freeze protection becomes.
• An ethylene glycol/water 50/50 mixture will give you protection down
to -34°F, and boil-over protection up to 250°F.
• Although regular water will work, the filling of the system should be
done with distilled water.
• The extra expense of distilled water holds a worthwhile benefit.
Distilled water doesn't contain any minerals which can dissolve at
higher temperatures and turn the coolant mixture into a corrosive
compound.
247. Coolant
• If you use a coolant in other than a 50/50 water/antifreeze mix you
can reduce the design operating temperature.
• Under moderate engine loads, each initial percent of glycol removed
(and water increase) from the coolant mixture reduces cylinder head
operating temperatures by about 1°F.
• There's a law of diminishing returns (maxing-out for a total reduction
of about 15°F.
• The point is that using a higher percentage of water will significantly
reduce coolant temperatures.
• However, the use of 100% distilled water as a coolant is inadvisable
because corrosion inhibitors and water pump seal lubricants are still
needed, even if freeze protection isn't.
248. Temperature Effects on
Performance
• An engine should be at its design operating temperature (usually
mid-gauge) to make good power.
• Operate at too low a temperature and the engine is less efficient
and makes less power. Higher temperatures are more
thermodynamically efficient, but run at too high a temperature and
you exceed the thermal expansion design basis of critical
components and raise fuel octane requirements.
• Modern fuel injected motorcycles use engine management
computers incorporating a coolant temperature sensor to retard the
engine ignition timing to compensate for any increase in octane
requirement when operating temperatures increase.
• Most stock-engined sport bikes are designed to produce their best
power when coolant temperatures are close to 200°F.
249. Coolant Temperature Sensor
•
Engines need more fuel when for a cold start as there is no heat in
the ports and chambers to keep the fuel atomized as vapour, so it
condenses.
• Fuel as a liquid burns very badly in the combustion chamber, so
throwing more at it ensures enough stays as vapour for some sort of
combustion.
• Injected engines get a very nice fuel spray from the injectors and
this is why injected engines behave better when cold.
A sensor monitors the engine coolant temperature so the computer
can supply additional fuel while the engine is warming up, and retard
ignition timing when the engine gets too hot.
• The sensor tells the ECU to stop warm-up fuel enrichment at 180°.
• So from a fuel correction standpoint, the proper operating
temperature is above 180°.
250. Overheating
•
The engine coolant temperature is controlled during low speed and
spirited-riding conditions using auxiliary air flow from a cooling fan.
• Although the temperature set-points are somewhat different for each
bike, here's generally how it's supposed to work.
• If the temperature goes above 200°F, the cooling fan starts, and
continues to run until the coolant temperature drops to 190°F.
• However, temperatures above 200°F are not considered outside the
range of normal operating conditions.
• Un-pressurized plain water boils at 212°F, so coolant systems are
designed with a pressure relief valve in the radiator cap in order that
even higher temperatures can be reached before coolant is released
from the coolant reservoir tank.
• Some bikes also have a coolant overflow tank to catch and prevent
the slippery coolant from reaching the road surface.
So, unless you're discharging coolant, you're not overheating.
251. Overcooling
•
When you first start your cold engine, the thermostat is shut so no
coolant can flow through the radiator.
• No coolant being sent to the radiator means you warm up faster.
This is good because, as you know, a cool engine often doesn't run
very well
• . Eventually, as the engine coolant warms up, it also warms the
thermostat. The thermostat has a bimetallic strip that opens a flow
valve, starting around 160°F degrees and being fully open around
190°F, your normal operating temperature at speed.
•
In cooler weather, lower air temperatures make your radiator more
effective at removing heat so your engine may not even reach it's
design operating temperature and performance will suffer
somewhat.
• Sometimes in this case, the coolant doesn't even get hot enough to
fully open the thermostat.
• In this case, you may want to block-off part of your radiator to
improve performance.
•
252. Temperature measurement
The temperature gauge displays the range of expected operating
temperatures. The midpoint is selected to correspond to the nominal
design operating temperature. If your temperature is below this point
you're not operating efficiently and you're down on power. If you're at
speed on a warm day you should expect to see temperatures
between the gauge midpoint and three-quarter point, usually 212°F.
The maximum gauge reading indicates the boiling point of a
pressurized 50/50 mix coolant, the point where the pressure relief
cap will likely discharge coolant to the overflow tank.
When you get stuck in stop-and-go traffic, the temperature will begin
to rise because now there is reduced airflow through the radiator. At
around the three-quarter point on the gauge, the radiator fan kicks-in
to provide the needed airflow. The fan stays on above this
temperature. With the fan operating, when the temperature drops to
just above the gauge midpoint, the fan stops running.
253. Temperature
• During these traffic conditions, temperatures in the upper
quarter of the gauge display should be expected and not
necessarily be a cause for alarm or an indication of
cooling system problems. Modern fuel injected engine
management computers quickly adjust the engine
ignition timing so as to run well at this higher
temperature.
You should also expect that the temperature will change
often and fairly quickly because, unlike a car, a
motorcycle only holds about 3-4 litres of coolant. So
there's not a lot of heat stored there.
254. Coolant System Modifications
If you've modified your engine, or your normal operating
conditions doesn't match the factory design condition,
then you may want to modify the cooling system to avoid
chronic overheating or overcooling.
For example, larger radiators that have larger heat
transfer surface areas are often used for track operating
conditions.
Unfortunately, a larger radiator might result in
overcooling when used on the street, but again, covering
a portion of the radiator in cooler or less demanding
operating environments will bring operating temperatures
back up to the gauge midpoint.
255. Radiator Damage
•
• One thing that's often overlooked on Ducati superbikes is that both
oil and coolant radiator fin damage occurs from road debris.
• Without protection, the fins get bent over, air flow through the
radiator is reduced, so coolant and oil temperatures rise over time.
After carefully straightening the bent fins, place aluminium window
screening over the radiators to prevent future damage.
• Screen material with larger openings won't stop small pebbles.
Don't worry, the inexpensive window screen material won't
significantly reduce airflow.
256. Additional Fans
• A second radiator fan, standard on some
models, will provide additional cooling capability
during low speed operation, high ambient air
temperatures, and track operation by increasing
the heat removal rate.
• However an additional 60W fan electrical load
not an prudent option for bike models that
historically been shown to have marginal
charging capacity or voltage regulator failures.
257. • Coolant Change Intervals
Coolants should be changed every two years because the corrosion
inhibitors they contain, deplete and become ineffective. The resulting
circulating corrosion products are particularly abrasive to water pump seals
and the low activity levels of old inhibitors can allow pitting of aluminium
radiator surfaces and general corrosion of metals in contact with the
coolant.
Recycling Coolant
Water treatment plants use biological processes and even highly diluted
ethylene glycol is toxic, so don't put it down the drain or storm sewers. Also,
apparently it has a sweet taste and will kill pets if left in puddles nearby.
Ethylene glycol is easily recycled so keep it with your used motor oil and
ask your local repair shop if they will take it, or how to safely dispose of it.
258. Coolant Alternatives
• You reduce operating temperatures when you increase
the percentage of water in a water/anti-freeze mixture.
• Plain distilled water has twice the heat transfer (cooling)
capability compared to glycol-based coolant mixes, but
shouldn't be used alone (100%) as a coolant.
• It lacks corrosion inhibitors and water pump seal
lubricating properties.
• So, even though water is the best choice for transferring
heat, cooling systems are designed using 50/50 ethylene
glycol because water alone freezes at 32°F.
259. Coolant Alternatives
• Silkolene Pro-Cool, Engine Ice, Liquid Performance,
Sand Evans NPG are coolants formulated with
propylene glycol that is less toxic, and consequently
environmentally more friendly than ethylene glycol
installed at the factory by most manufacturers.
• Engine Ice is simply propylene glycol premixed 50/50
with de-ionized water.
• There have been anecdotal reports of accelerated wear
of water pump seals on engines cooled with Engine Ice,
but this seems unlikely to be caused by the coolant itself.
260. Coolant Alternatives
• Even though propylene glycol has a higher boiling point than
ethylene glycol, when mixed with water it is less effective in both
removing heat from your engine and transferring it to your radiator.
• So, it seems that the only logic for using it is to minimize coolant
discharge to racetracks, not for reducing operating temperatures.
Glycols are slippery and hard to clean off the track since it doesn’t
evaporate quickly like water.
Evans NPG is non-aqueous propylene glycol (i.e. that is not mixed
with water.) It has a higher boiling point of 370°F that is said to
reduce vapour blanketing at engine hot spots for more efficient heat
transfer. Also, since it doesn't contains any water, it should be safe
to use in bikes having magnesium cylinder gaskets, body parts and
wheels.
265. Engine Design and Optimization
• Engineers design, develop, and optimize engine systems,
assemblies, and components to improve performance, engine power
output, fuel economy, exhaust emissions, and component costs.
• Using advanced design and analysis tools early in the design stage,
engineers determine optimum engine parameters, including:
• Intake and exhaust system layout
• Piping length and diameter
• Plenum volume
• Cam profile
• Valve sizes
• Compression ratio
• Journal bearings
266. Engine Performance Mapping
and Development
• Research houses develop and test spark-ignition
engines ranging from model airplanes to locomotives.
SwRI engineers regularly conduct tests to evaluate
engine performance, emissions, and fuel economy
development. Using a wide range of sophisticated
engine measurement techniques and development tools,
engineers provide the following services:
• Camshaft development
• Intake system design and tuning
• Exhaust system optimization
• Electronic fuel system development and testing
• Cylinder head flow measurement and analysis
• Motoring friction analysis
267. Engine development
• During the engine development process,
engineers use state-of-the-art diagnostic tools
and techniques, including:
• Combustion system visualization
• Knock and misfire detection
• In-cylinder airflow and fuel-air mixing
measurement
• Real-time oil consumption measurement
• Piston and ring motion measurement
• Computer cycle simulation
268. Vehicle Benchmarking
• Engineers evaluate, analyze, and compare vehicles and
electrical and mechanical systems to provide a scientific,
nonbiased comparison of any vehicle. They Institute
testing, research, and development programs includes a
comprehensive range of research areas, e.g.:
• Performance
• Emissions
• Fuel consumption
• Drivetrain efficiency
• Vehicle handling
• Fuel system components
• Engine component design
269. Benchmarking
• A wide variety of
components, such as
pistons, injectors, and
crankshafts, are
evaluated for
reliability and their
effects on fuel
consumption, power
output, and exhaust
emissions.
270. Engine Durability Testing
• Using industry standard or user-specified test
cycles, Engineers routinely perform continuous,
long-term engine testing to evaluate engine
reliability and component durability.
• Open or closed-loop control of the engine and
test conditions is provided with a variety of
hardware and software platforms.
• Specially equipped test cells allow a wide
spectrum of test capabilities, including altitude
simulation, low-temperature environment (-
35ºC), thermal cycling, and continuous engine
monitoring.
272. What you should measure
• In-cylinder combustion pressure
monitoring and analysis
• Combustion heat release analysis
• Coolant, oil, exhaust, and radiated
heat rejection determination
• Engine teardown inspection
• Exhaust emission evaluation
• Failure analysis
• Fuel analysis
• Real-time component wear
measurement
• Real-time oil consumption
measurement
• Thermal imaging
• Blow by monitoring
• Air filter efficiency evaluation
• High-pressure leak down
determination
273. Environmental testing
• Using advanced
environmental chamber
testing, engineers monitor
hot and cold engine and
vehicle performance.
Chassis and engine
dynamometers in the
cells aid in developing
cold-start strategies, fuel
injection calibration, and
hot vehicle component
evaluation.
274. Engineers use finite element analysis to improve crankshaft shape and
optimize crank and throw of geometry, such as fillets and web shapes.
• finite element analyses of
all major engine
assemblies and
components such as:
• Cylinder heads
• Blocks
• Pistons
• Connecting rods
• Crankshafts
• Valve trains
• Fuel system components
275. CFD
• Advanced computational fluid dynamic
techniques to model and simulate the action of
numerous gases and liquids in engine-related
components and systems, including:
• Combustion chamber
• Fuel injection system
• Fuel mixing
• Intake and exhaust ports
• Engine block and cylinder head cooling
277. 3D Solid modelling
• Using three-
dimensional solid
modelling, engineers
prepare kinematic
analysis of a
proposed valve train
assembly.
278. Radioactive Tracer Technology
Measuring Real-Time Wear in Operating
Engines
• For 40 years, many Institutes have used radioactive
tracer techniques to make highly accurate and sensitive
real-time wear measurements in operating engines.
These capabilities are particularly important in light of the
harsh operating and environmental conditions imposed
on today's high-performance engines, in which
performance as well as low emissions levels increasingly
depend on close-tolerance operation with minimal wear.
Using sophisticated instrumentation, studies real-time
wear, detecting wear and wear rate changes instantly.
Advantages of radioactive tracer measurement
techniques include:
279. Radio active measurement
• Cost effective tests
• Repeatable measurements
• Real-time wear data
• Meaningful results for short tests
• Easily measured transients
• Identification of cause and effect relationships
• Association of wear with specific design
parameters, fuel and lubricant characteristics,
and engine operating conditions
280. Radio active tracer
• Two radioactive tracer
techniques are typically used
to measure internal
combustion engine component
wear:
• bulk activation and surface- or
thin-layer activation
(SLA/TLA). The appropriate
method is based on specific
test objectives, component
metallurgy, and configuration
or site particulars. measures
wear as a function of lubricant
and engine operation
parameters using bulk
activated rings and connecting
rod bearings in a test engine.
