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Spark Plugs

Chapter 2

Study Tips  

The spark plugs are critical parts that dominate 
the engine combustion and bear a major 
responsibility for higher engine performance.

Spark Plugs

Chapter 2  Spark Plugs

15

3 Types

Types

1

2

3

Needle to needle

Iridium Plug

4

Genuine iridium

5

Resistor

6

U-groove

7

Platinum ZU

8

Platinum

9

For rotary use

10

Extended

11

Semi-surface

discharge

12

3 electrodes

13

Compact type

14

Taper seat

15

For motorcycle

16

Main types of spark plugs

P.16

P.17

P.18

P.18

P.19

P.19

P.20

P.20

P.21

P.21

P.22

P.22

P.23

P.23

P.23

P.24

Summary of Contents for CAFITESSE 300

Page 1: ...http www globaldenso com PLUG http www denso co jp PLUG Formula1 PANASONIC TOYOTA RACING Ralf Schumacher Super GT DENSO SARD SUPRA Andre Couto Ronnie Quintarelli WGP250 LCR Casey Stoner ...

Page 2: ...es 3Victories 1Victory 1Victory WGP125 Noboru UEDA Masao AZUMA WGP125 Noboru UEDA Masao AZUMA DUCATI916 C Fogarty WGP250 Naoki MATSUDO Taro SEKIGUCHI Rd 1Suzuka IRIDIUMPOWER WGP DebutWin DENSO Racing Plug IQ01 31 GT500 Champion Castrol TOM S GT500 CHAMPION Castrol TOM S GT500 CHAMPION GT500 Champion TOYOTA F1 Team Taking Malaysian GP Podium Position TOYOTA F1 Team Taking Malaysian GP Podium Positi...

Page 3: ...KI KURZ L DOVES 1 rider T N AMA EAST CHAMPION AMA EAST CHAMPION JSB 1000 CHAMPION JSB 1000 CHAMPION IB 125 CHAMPION IB 125 CHAMPION PROSTOCK CHAMPION PROSTOCK CHAMPION PROSTOCK CHAMPION PROSTOCK CHAMPION Corporate sponsor ry 7Victories 7Victories 3Victories 3Victories 2Victories 2Victories WGP125 Masao AZUMA Yoichi UI WGP125 Yoichi UI WGP125 Toshinaga KUZUHARA Tomoyoshi KOYAMA WGP250 Team LCR Robe...

Page 4: ...DENSO SUPPORT DRIVERS RIDERS WRC SUBARU WORLD RALLY TEAM Petter Solberg WGP125 AJO MOTORSPORTS Tomoyoshi Koyama WGP250 TEAM LCR Roberto Locatelli 03 ...

Page 5: ...ly set when fitting P58 Q19 How do I select the correct heat range when fitting to my vehicle P59 Q20 How would compare against high performance spark plugs offered by other spark plug manufacturers P59 Q21 Is there anything I need to be aware of when fitting P60 Q22 Can the gap be adjusted Can I use any spark plug cleaners with the P60 Q1 What type of spark plug is the P66 Q2 What makes the ignit...

Page 6: ...2 Compresses the air fuel mixture to high temperature and high pressure Intake and compression stroke 1 When the piston rises and the cylinder side compresses the crank case side is a vacuum and takes in the air fuel mixture Combustion and exhaust stroke 2 When the piston is pushed down by the combustion the air fuel mixture on the crank case side is sent to the cylinder side where it pushes out t...

Page 7: ... raising the compression ratio provides larger combustion pressure but if the pressure is too high knocking occurs General engines are designed for compression ratios of 9 10 The proportion by weight of gasoline and air in the air fuel mixture these proportions must be varied with the engine state Stoichiometric air fuel ratio about 15 1 Stoichiometric value for complete combustion Output air fuel...

Page 8: ... in the secondary coil through coil self inductance and mutual inductance The high voltage is generated when the primary current is cut off Igniter 3 In order to generate the high voltage required for ignition in the ignition coil the current flowing through the primary coil is cut off Distributor 4 The high voltage generated by the ignition coil is distributed in the correct order to the spark pl...

Page 9: ...ween the contacts or the voltage drops at low speed Also sometimes current does not flow adequately due to soiling of the contact surface This system generates high voltage by cutting off the current with transistors in the igniter This system can provide stable high voltage Demerit The ignition timing is controlled by the signal generator in the distributor so there are limits to fine control The...

Page 10: ... electrical spark occurs because the fuel particles between the electrodes are activated by the spark to discharge a chemical reaction oxidation is triggered the heat of reaction is generated and the flame core is formed This heat activates the surrounding air fuel mixture eventually a flame core is formed that spreads the combustion to the surroundings itself However if the quenching effect betwe...

Page 11: ... electrodes 3 Between b and c is called the capacitance spark At the start of the discharge the spark is generated by the electrical energy stored in the secondary circuit The current is large but the duration is short 4 Between c and d is called the inductance spark The spark is generated by the electromagnetic energy of the coil The current is small but the duration is long From the c point the ...

Page 12: ...n pressure The compression pressure is higher for low speed and high load Sudden acceleration for starting out fits these conditions so higher voltage is required then and misfire occurs more easily Compression pressure 3 P Compression pressure T Air Fuel mixture temperature V Required voltage The required voltage drops as the air fuel mixture temperature rises The lower the engine temperature the...

Page 13: ...ssure changes 2 In an environment in which the temperature and pressure are constantly changing drastically spark plugs must have adequate insulation to withstand high voltages that reach about 10 30 kV Has insulation at high voltage 3 Spark plugs must maintain an airtight seal between the housing and the insulator under conditions of drastic temperature and pressure change and high voltage DENSO ...

Page 14: ... 4 3 3 2 2 1 1 Insulates the terminal center shaft and center electrode from the housing preventing escape of high voltage from the electrodes Since the bottom of the insulator projects into the combustion chamber high purity alumina with superior heat proof characteristic mechanical strength excellent insulation and thermal conductivity at high temperature etc is used Insulator 1 1 The terminal i...

Page 15: ...y is used for the center electrode to reduce electrode wear Copper is sealed into the center section to improve thermal conductivity Electrode with copper 8 8 A new iridium alloy tip with a diameter of 0 4 mm is laser welded to the tip of the center electrode to make the center electrode ultra fine This lowers the required voltage secure reliable spark reduces the quenching effect and improves ign...

Page 16: ...Plugs Chapter 2 Spark Plugs 15 3 Types Types 1 2 3 Needle to needle Iridium Plug 4 Genuine iridium 5 Resistor 6 U groove 7 Platinum ZU 8 Platinum 9 For rotary use 10 Extended 11 Semi surface discharge 12 3 electrodes 13 Compact type 14 Taper seat 15 For motorcycle 16 Main types of spark plugs P 16 P 17 P 18 P 18 P 19 P 19 P 20 P 20 P 21 P 21 P 22 P 22 P 23 P 23 P 23 P 24 ...

Page 17: ...t ground electrode U groove ground electrode Ultra fine 0 4 mm diameter iridium alloy center electrode Increased center electrode projection Insulator projection All round laser welding Terminal Nut Built in high reliability resistor Plated with highly corrosion resistant nickel 9 9 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 The finer the electrodes the more the potential concent rates at the electrode tip a...

Page 18: ...the contact area with the flame core is small the quenching effect is reduced and the ignition performance is improved can replace almost all normal spark plugs in Japan and overseas When replacing normal spark plugs with check in the application table For normal engines replace with the same heat range as the spark plugs being replaced for a tuned engine select spark plugs that match the tuning l...

Page 19: ... alloy center electrode Racing insulator Spark cleaning pocket Silicon oil application Housing end chamfer All round laser welding Terminal Built in high reliability resistor Plated with highly corrosion resistant nickel 10 10 9 9 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 The ground electrode of this revolutionary iridium plug features DENSO s very own technology and is needle shaped resulting in an unparal...

Page 20: ...k plugs for the Toyota Century New 3 electrode iridium spark plugs Example SK20BR11 The design of these spark plugs is optimized for direct injection burning off carbon The spark is at the main electrode normally and at the side electrode when the main electrode is sooty Used as the genuine spark plugs for the Toyota Crown 3 liter direct injection engine Iridiumφ0 7 tip Platinum tip Side electrode...

Page 21: ...o obtain large ignition energy Since it is possible to reduce the spark voltage without enlarging the spark plug gap superior ignition performance is attained K16R U11 Platinum ZU 8 This spark plug uses 0 7 mm diameter ultra fine special platinum alloy for the center electrode to improve sparking and uses a U groove and taper cut for the ground electrode to improve ignition 8 7 Platinum 1 1 1 1 W3...

Page 22: ...e platinum tips welded to the center electrode and ground electrode The tips of the center electrodes are finer than those of ordinary spark plugs They greatly improve fuel consumption driveability and durability and support maintenance free operation For DLI discharge Platinum spark plugs Example PK20R P11 In order to prevent wear from discharge the volume of platinum for the ground electrodes ha...

Page 23: ...e discharge structure to the ground electrode improves the ignition fouling proofing and durability Semi surface discharge spark plugs Example W20EKR S11 W20EPR S11 The use of semi surface discharge improves ignition and fouling proofing The W20EKR S11 is used in Honda and the W20EPR S11 is used in Mitsubishi semi surface discharge 2 electrode spark plug Example W20ETR S11 2 ground electrodes are ...

Page 24: ...ct spark plugs Example Q16R U11 Q16PR U11 By reducing the hexagonal width across flats to 16 mm lighter spark plugs were attained ISO compact spark plugs Example K16R U11 K16PR U11 Spark plugs that meet ISO standards Be careful when installing these spark plugs The height H is 2 5 mm shorter than for the Q type Compact spark plugs for mini sized cars Example XU22EPR U By reducing the hexagonal wid...

Page 25: ...mm L 19 mm Example W27EMR C Spark plug with compact insulator head section Only for Suzuki and Honda Example U27FER9 φ10 mm L 19 mm half threads Ignition is improved by widening the gap from 0 6 0 7 mm for previous models to 0 9 mm Only for Honda Example U31ETR The heat proofing is improved by having two ground electrodes For Kawasaki and Suzuki Example U27ESR N φ10 mm L 19 mm all threads The foul...

Page 26: ...ermined by the temperature of the gas inside the combustion chamber and the spark plug design Water Cooled by intake air fuel mixture 2 2 1 1 Low heat range and high heat range Low heat range plugs have long insulator leg sections and the surface area affected by the flame and the gas pocket capacity are large Also since the heat release path from the insulator nose to the housing is long heat dis...

Page 27: ...e carbon is naturally burnt away comple tely by combustion Spark plug temperature and vehicle speed 3 pre ignition temperature When the center electrode reaches 950 C or higher pre ignition early ignition occurs meaning that the electrode serves as a heat source and ignition occurs without a spark Therefore output falls and this can reach the level of electrode wear and insulator damage Spark plug...

Page 28: ... type and usage conditions but for normal nickel alloy plugs it is approximately in the range of 0 10 0 15 mm for each 10 000 km driven Electrode wear Rise in required voltage The required voltage rises in proportion to the distance driven This rise in the required voltage is large until the sharp section at the end of the center electrode is worn round to some degree about 4 000 km After that the...

Page 29: ...val replacement after the number of kilometers in the figure above is recommended However 100 000 km for platinum iridium spark plugs If a thread lubricant such as grease is coated on the thread tightening to the recommended torque is tightening too much this has been linked to seal leakage Do not use a thread lubricant Tightening more than the tightening angles and torques shown on the right coul...

Page 30: ...ect appropriate spark plugs for the engine and vehicle type so use the specified spark plugs I High performance spark plugs W Thread Diameter and Hex Size 16 Heat range E Reach X Shape type R Internal Construction U Shape type 11 Gap High Performance Plug Thread Diameter and Hex Size Heat Range Reach Shape Type Internal Construction Shape Type Gap High Performance Plug Shape High Performance Plug ...

Page 31: ...ce Plug Thread Diameter and Hex Size Heat Range Reach Shape Type Internal Construction Shape Type Gap Shape Shape High Performance Plug Thread Diameter and Hex Size Heat Range Reach Shape Type Internal Construction Shape Type Gap Shape Type Shape High Performance Plug Thread Diameter and Hex Size Heat Range Reach Shape Type Internal Construction Shape Type Gap Internal Construction Shape High Perf...

Page 32: ... effective method for elucidating the cause of engine troubles The insulator leg section has light gray or tan deposits and slight electrode erosion Normal Appearance The insulator foot section and electrode section are covered with dried soft black carbon Results Poor starting misfiring acceleration defect Cause Repeated short distance driving driving with the engine cool incorrect choking overly...

Page 33: ...the air fuel ratio leaner Fuel fouling 3 Appearance The center and ground electrodes are rounded and the gap has become too wide Result Poor starting and acceleration Cause Inadequate maintenance spark plug has exceeded its service life Extreme electrode wear 4 Appearance The gap is wider than appropriate Result Poor starting and acceleration Cause The gap is inappropriate the wrong spark plug was...

Page 34: ...s is due to overheating pre ignition is a phenomenon in which combustion occurs before ignition The plug heat range is too low the injection timing is too advanced etc Pre ignition 2 Appearance The insulator nose section is cracked or broken Results Misfiring Cause Severely abnormal combustion lack of attention to gap adjustment Insulator breakage 3 Appearance Thread screw section melting Result P...

Page 35: ...gnition performance 2 Thanks to DENSO s unique U groove ground electrodes they secure a large volume for flame core formation 3 The new iridium alloy for the center electrodie improves the oxidation resistance at high temperature 4 They have longer service life than vehicle manufacturer s genuine iridium spark plugs 5 When using spark plugs in vehicles which have used normal spark plugs check in t...

Page 36: ...e coil generates counter electromotive force but this does not rise higher than the battery voltage Therefore the change in the magnetic flux is softened and the voltage generated in the secondary coil is so low that it does not reach the discharge voltage Let us try 1 If you line up the two coils and pass current through one coil the primary coil magnetic flux is generated When a constant current...

Page 37: ...alled self induction action The induced electromotive power works to obstruct the change in the current Therefore when current is passed through a coil the self induction action works to obstruct that current so it takes time for the current to flow into the coil This phenomenon is called the primary current rise time Current Counter electromotive force due to self induction 2 2 1 1 Switched off S...

Page 38: ...primary current to be constant from low speed to high speed One method for this control is dwell angle control Ignition coil This generation of high voltage through such coil self induction action and mutual induction action takes place within the ignition coil The ignition coil has two coils the primary coil and the secondary coil and their winding ratio is about 1 100 The actual connecting and c...

Page 39: ...il the primary current reaches 12A it is obstructed by the self induction action so some time t is required Dwell angle control 3 When the dwell angle is constant as the engine speed reaches high speed the energized duration becomes shorter so the primary current decreases and the secondary voltage decreases too Therefore when the engine is rotating at high speed if the start of the energized dura...

Page 40: ...mum pressure when the maximum pressure due to combustion comes at the position where the crankshaft position is about 10 degrees after top dead center ATDC10 CA so the ignition timing is set ahead of that time by the duration of the flame propagation and the ignition lag Furthermore since the combustion speed until the maximum pressure is reached depends on the engine speed the engine load etc it ...

Page 41: ...t the incorrect one The winding ratio between the comparatively thick primary coil and the comparatively thin secondary coil is about 1 100 1 The primary coil energized duration expressed as the distributor rotation angle is called the dwell angle 2 When the primary coil current is switched Off mutual electromotive induction power is generated in the secondary coil 3 As the engine speed increases ...

Page 42: ...n increased Reduced voltage loss using a 7 rib design Example S29A Semi SurfaceGapPlugforRotaryEngines Using a U grooved ground electrode a large ignition performance is obtained allowing even lean mixtures to be ignited easily The spark position is extended into the ignition chamber improving combustion efficiency fuel consumption and drivability Example J16AR U11 For Mazda and Mitsubishi Vehicle...

Page 43: ... Plug By reducing the hex size 16mm the plug has been made smaller Example Q16R U11 Q16PR U11 Small Hex Plug 12mm Diameter X 19mm Length Example X24EPR U9 Plug with a compact insulator head For Suzuki and Honda Example W27EMR C A 10mm Diameter X 19mm Length half threaded With a wider gap of 0 9mm compared to conventional plugs 0 6 to 0 7mm this plug has improved ignitability For Honda Example U27F...

Page 44: ... alloy that has a high melting point has enabled miniaturization of the center electrode Required voltage has been lowered and firing performance improved All types Japan 2877035 2921524 3000955 U K 2302367 U S A 5977695 6078129 6093071 6094000 6262522 People s Republic of China 961022841 Republic of Korea 0292083 Highly corrosion resistant 2 bright nickel plating Bright nickel plating as used in ...

Page 45: ...lectrode the cooling effect is great and sometimes firing does not occur as shown in Figure 4 The characteristics of this firing is called firing performance To improve firing performance the contact area between the electrode and the flame nucleus needs to be made reduced in size Accordingly the electrode was made as fine as possible in the I to improve firing performance The smaller the electrod...

Page 46: ...stance welding cannot be used because the iridium does not melt enough and an adequate weld strength cannot be guaranteed All round laser welding which employs a high energy laser is used in the to melt and weld all around welding points Because all area to be welded is completely melted the welding point is extremely reliable thus ensuring stable and quality response without changes in the electr...

Page 47: ...eated in discharge The usual way of ensuring this is increasing the spark gap but this also increases the required voltage and thus places a great load on the ignition coil and plug cords Spark gap small Spark gap small Ground electrode with U groove Good Spark gap small Spark gap large Flame nucleus Bad Normal electrode The ground electrode with its U groove maintains a large volume of space with...

Page 48: ...ic of spark plugs it is important to minimize the portion of the electrode that comes in contact with the flame nucleus Because the area of the ground electrode with tapered cut that comes into contact with the flame nucleus is small the heat lost to the electrode is lessened and firing performance improves dramatically Also the surface area and weight of the ground electrode tip is reduced and so...

Page 49: ...ng life spark plugs The center electrode in both is made from the new iridium alloy but the purpose of both are different Therefore the electrode diameter and ground electrode specifications also differ DENSO precious metal spark plugs are classified into the four types shown in the following table according to the center electrode material and type ZU plug φ0 7 φ0 4 Iridium plug φ0 7 High perform...

Page 50: ... 6 Silver Ag Melting point Strength Electricalresistance Hardness Iridium has high material strength compared to other materials and provides stable performance under heavier driving conditions Because the electrical resistance is lower than platinum and the base material of electrodes nickel iridium is suitable for use in spark plug electrodes Iridium is harder than other materials and has great ...

Page 51: ... to Q7 iridium is an extremely hard material In the past sintering material was generally cut and this meant high costs and restrictions on processing form and dimensions Therefore it could not be used as a material in spark plugs However our new precious metals technology has meant that we can now process iridium by drawing it in its melted form This enables iridium to be processed in all dimensi...

Page 52: ...ny additives with a view to improving the corrosion resistance of iridium and has now developed a new iridium alloy the alloy of iridium and rhodium highly suitable for use in spark plug electrodes This new product is covered by the following DENSO patents JP2877035 GB2302367 and other patents pending in USA Germany Canada Italy and South Korea The following photographs compare the durability of t...

Page 53: ...an spark the better firing performance a plug is said to have The following graph shows some examples of ignitability limits for various spark plugs Test engine 1600 cc 4 valve 4 cylinder Good 10 0 6 0 8 1 0 1 2 1 4 1 6 11 12 13 14 15 16 17 18 mm Ignitability Limits Air Fuel spark plug gap Lean Rich Normal plug φ2 5 Platinum plug φ1 1 φ0 4 Compared to normal spark plugs with a spark gap of 0 8mm t...

Page 54: ...t in engines This means that the required voltage of spark plugs tends to increase and high compression is required in highly tuned engines When this occurs the required voltage increases and in the worst case sparking ceases while the engine is running Minimization of the electrode diameter is an effective way of avoiding this Refer to the answer for Q2 In the the center electrode has a diameter ...

Page 55: ...es to work properly during idling This stabilizes the idling revolution count and quietens the engine The following graph gives some examples of idling revolution counts 600 650 700 0 10 20 30 40 Time passed seconds Engine revolution count Normal plug Variations small Variations large rpm Engine 1600cc 4 valve 4 cylinder Whereas normal plugs have highly variable revolution counts the maintains ver...

Page 56: ...ed thus improving fuel consumption during idling The following graph is the comparison of fuel consumption during idling Spark plug Center electrode mm Normal plugs Fuel consumption h φ0 4 φ2 5 0 53 0 54 0 57 0 55 0 56 Good Spark plug Center electrode mm Normal plugs Fuel consumption h φ0 4 φ2 5 2 23 2 24 2 27 2 25 2 26 Good What happens to fuel consumption when is used Q14 A In many cases fuel co...

Page 57: ...lowing graph is an example of an acceleration test 50 100 150 km h Speed Difference of 0 7 seconds Time Normal spark plug φ0 4 Differenceof6m Distance run m 790 800 810 Spark plug Centerelectrodediameter mm Normal spark plug φ2 5 Good Vehicle 250 cc 2 cycle water cooled V2 cylinders Conditions Fixed in sixth gear Flat out acceleration from 50 km h using an automatic driving device Vehicle 250 cc 2...

Page 58: ... type For normal engines select a spark plug with the same heat range as a standard spark plug For highly tuned engines select one with the heat range that suits the tuning level K16PR K16R U KJ16C BKR5 ZFR5F J K16TR PFR5 PK16 PKJ16 K20PR K20R U KJ20C BKR6 ZFR6F J K20TR PFR6 PK20 PKJ20 PZFR6 K22 IRIWAY7 BKR7E R6326 7 R6255 7 07 ISO R6427 7 K24 IRIWAY8 R6326 8 R6255 8 08 ISO R6427 8 K27 IRIWAY9 R63...

Page 59: ...ill be able to be fitted into almost any car Does the engine need to be specially set when fitting No The plugs can just replace the ones you take out Q18 A The spark plug itself has a low required voltage and high ignitability and is able to draw out the power of an engine The superb performance of spark plugs is obtained merely by installing them in your vehicle And of course there is no need fo...

Page 60: ...lectrode material Tapered cut Blue Platinum Project Gold VX spark plug Iriseries spark plug ZU spark plug φ0 9 φ2 0 φ0 8 φ0 6 φ0 7 φ0 4 Platinum Gold palladium alloy Platinum alloy Iridium alloy Platinum alloy Iridium alloy Yes Yes Yes Yes Yes Yes BOSCH CHAMPION NGK DENSO 1 2 3 4 The use of an iridium alloy for the ultra fine 0 4 mm diameter center electrode a tapered cut synonymous with high perf...

Page 61: ...of the spark plug to ensure that no burring occurs 2 When removing the spark plug ensure that no fouling such as oil on the outside of the plug enters inside the engine 3 When installing spark plugs clean the seat for the spark plug in the engine check the gasket and then mount the plugs on their seats 4 Place the plugs in vertically and screw in by hand until tight 6 Do not over tighten spark plu...

Page 62: ...roen and Yamaha Marine Iridium Tough VKH16 VKH20 and VKH22 are also on sale at the same time ITV16 ITV20 ITV22 ITV24 ITV27 ITV series 14mm dia X 25 0mm length tapered seat long reach type For the Ford Focus Mondeo Escape Chevrolet Blazer and Mazda Tribute IWM24 IWM27 IWM31 IWM series This type has a gasket face height shortened by approximately 10mm from the IW Type The Iridium Power version of th...

Page 63: ...0 7 0 9mm ignitability is greatly increased By making this a single electrode the spark location is stabilized compared to in normal types double ground electrode securing an ideal combustion condition IUH24 IUH27 IUH series 10mm dia X 19mm length half threaded type Using the high heat resistance of the iridium electrode the spark position is extended 0 4mm compared to standard types 1 6 2 0mm For...

Page 64: ...RC 5 I19 0 42511 05319 9 067700 8920 IW34 14 19 20 6 0 7 0 5 1 5 3 6 RC 5 I20 0 42511 05320 5 067700 8930 IWM24 INSULATOR COMPACT 14 19 20 6 0 8 1 5 0 5 2 7 S 5 I91 0 42511 05391 5 267700 2890 IWM27 INSULATOR COMPACT 14 19 20 6 0 8 1 5 0 5 2 7 S 5 I92 0 42511 05392 2 267700 2900 IWM31 INSULATOR COMPACT 14 19 20 6 0 8 1 5 0 5 2 7 S 5 I93 0 42511 05393 9 267700 2910 New IWF16 14 12 7 20 6 0 8 1 5 3 ...

Page 65: ... 18 0 9 1 5 2 8 5 0 R 5 I75 0 42511 05375 5 067700 9380 IX24B 12 19 18 0 9 1 5 2 8 5 0 R 5 I76 0 42511 05376 2 067700 9390 IX27B 12 19 18 0 9 1 5 2 8 5 0 R 5 I77 0 42511 05377 9 067700 9400 IXG24 SHROUD 12 22 18 0 7 0 7 2 0 4 1 R 5 I94 0 42511 05394 6 267700 2920 IXG27 SHROUD 12 22 18 0 7 0 7 2 0 4 1 R 5 I95 0 42511 05395 3 267700 2930 New IU20 10 19 16 0 9 0 5 0 7 2 6 R 5 I60 0 42511 05360 1 2677...

Page 66: ...DENSO Spark Plugs Package Lineup Asia Europe USA IRIDIUM PLATINUM General Japan TYPE MARKET 65 ...

Page 67: ...he plug high resistance against corrosion Platinum taken from proven platinum plug technology has been added to the ground electrode The long life of a platinum plug is assured by greatly reducing electrode wear The resistor specification is similar to all types However a high reliability monolithic resistor is built in This shuts out noise to all other electrical equipment The union of the iridiu...

Page 68: ...he electrode also has a quenching cooling effect effect where the electrode takes away the heat of the spark as soon as firing occurs Therefore in a thick electrode the cooling effect is large and sometimes firing does not occur as shown in Figure 4 The characteristics of this firing is called ignitability To improve ignitability the contact area between the electrode and the flame kernel needs to...

Page 69: ...aphs below the spread of combustion for and a normal spark plug Clearly the result is a much faster spread of combustion with With combustion has spread throughout nearly the entire combustion chamber within 4 1000 seconds of discharge The normal spark plug has only spread half as much in that time The regular plug also fails to spread the flame in some occurrences The same combustion results occu...

Page 70: ...stance welding cannot be used because the iridium does not melt enough and an adequate weld strength cannot be guaranteed 360 laser welding which employs a high energy laser is used in the to melt and weld all around welding points Because all area to be welded is completely melted the welding point is extremely reliable thus ensuring stable and quality response without changes in the electrode ev...

Page 71: ...ppressing electrode wear at discharge and providing the working life of a platinum plug Tapered cut U groove Platinum Material composition of iridium By adding a small amount of rhodium to the primary iridium material resistance to oxidation is increased and corrosion in the high temperature combustion environment is suppressed Japan Patent 2877035 UK Patent 2302367 US Patents 6094000 6262522 Peop...

Page 72: ... of electrodes nickel iridium is suitable for use in spark plug electrodes Electrical resistance Iridium has high material strength compared to other materials and provides stable performance under heavier driving conditions Strength The melting point of iridium is approximately 680 higher than that of platinum and is difficult to melt even in the high temperatures produced by electrical discharge...

Page 73: ... iridium is an extremely hard material In the past sintering material was generally cut and this meant high costs and restrictions on processing form and dimensions Therefore it could not be used as a material in spark plugs However our new precious metals technology has meant that we can now process iridium by drawing it in its melted form This enables iridium to be processed in all dimensions an...

Page 74: ...ed Kingdom the United States People s Republic of China and Republic of Korea Japan Patents 2877035 3000955 2921524 UK Patent 2302367 US Patents 6094000 6262522 5977695 6078129 People s Republic of China Patent 961022841 Republic of Korea Patent 0292083 The following photographs compare the durability of the new iridium alloy and pure iridium when used in an engine under the same conditions Meltin...

Page 75: ...ng even under running conditions that easily cause poor igniting performance at idling or acceleration Ordinarily the leaner the air mix the more difficult the ignition The greater the ignitability limits that is the leaner the air mix in which a plug can spark the better ignitability a plug is said to have The following graph shows some examples of ignitability limits for various spark plugs 0 4 ...

Page 76: ...in the worst case sparking ceases while the engine is running Minimization of the electrode diameter is an effective way of avoiding this In the the center electrode has a diameter of 0 4mm Because required voltage is kept low this enables the to be used in high performance engines and for high response driving The following graph gives examples of required voltage measurements for and normal spar...

Page 77: ...greatly improved combustion This in turn makes emissions much cleaner Vehicle 2000cc 4cyl 4 cycle Operating condition 11 modes CO 5 17 5 80 5 0 5 2 5 4 5 6 5 8 6 0 11 improvement Emissions g km Emissions g km Emissions g km HC 0 422 0 486 0 40 0 42 0 44 0 46 0 48 0 50 13 improvement NOx 0 221 0 270 0 20 0 22 0 24 0 26 0 28 0 30 18 improvement Normal spark plug 2 5 Normal spark plug 2 5 Normal spar...

Page 78: ...ons This improves fuel consumption since favorable engine performance is maintained even when minimum required fuel is being used The following plug performance is an example of improved fuel consumption at fixed 60km h running 15 760 15 231 3 5 improvement over normal spark plugs 15 2 15 4 15 6 15 8 16 0 Fuel Consumption km l 15 646 Vehicle 2000cc 4cyl 4 cycle Normal spark plug 2 5 Platinum plug ...

Page 79: ...ess misfiring in areas where firing is difficult No matter how heavy the conditions high response driving is enabled As a result acceleration is better than when normal spark plugs are used The following graph is an example of an acceleration test Vehicle 2000cc 4cyl 4 cycle Operating condition Creep 2nd Full Open 100km h Normal spark plug 2 5 Vehicle speed km h Time passed seconds There was a dif...

Page 80: ...istance work life starting power and acceleration 2 4 6 8 10 Output Life time Anti fouling characteristics Acceleration Startability Platinum plug Normal spark plug DENSO Data Comparison Performance of other plugs as measured against with value of 10 How does the compare to the 0 6mm iridium plugs platinum plugs and normal spark plugs 0 4 1 1 2 5 ...

Page 81: ...able select an to suit your car from the following table which lists spark plugs by vehicle type Comparative spark plug table For normal engines select a spark plug with the same heat range as a standard spark plug For highly tuned engines select one with the heat range that suits the tuning level DENSO NGK VK VQ VW VXU VK20Y VK G VKA VKB VKH VT IK IQ IW IXU IK G IKH IT K PR K R U KJ C K TR PK PKJ...

Page 82: ... engine Ordinarily the heat range of a highly tuned engine tends to be colder Refer to the following table to compare the heat range of the and other spark plugs The itself has a low required voltage and high ignitability and is able to draw out the power of an engine The superb performance of is obtained merely by installing them in your vehicle And of course there is no need for special tuning 8...

Page 83: ...iameter mm Center electrode material Ground electrode specifications Iridium IX Iriseries Iridium sintering material Yttria added Iridium sintering material Yttria added Tapered cut Tapered cut Iridium alloy Rhodium added Iridium alloy Rhodium added Tapered cut U groove Platinum attached No tapered cut Platinum attached No tapered cut DENSO 00 4 97 4 98 5 00 6 High performance Long life Ultra high...

Page 84: ...am modeling each electrode shape requires less voltage than the 2 electrode plug Ignitability Cooling effect from the electrode decreases and ignitability increases to the extent that the contact area between the flame kernel and electrodes is smaller Due to its 0 4mm center electrode has less contact area between the flame kernel and electrodes and better ignitability than 2 electrode plugs Plug ...

Page 85: ...been linked to seal leakage Do not use a thread lubricant Tightening more than the tightening angles and torques shown on the right could result in damage to the engine and furthermore could result in the plug coming off at the thread 1 IUH27ES U24FER9S 2 PK22PR L11S SK22PR M11S IK16G IK20G IK22G VK16G VK20G VK22G K20PR U9S SK20PR L9S SKJ20DR M11S KJ20DR M11S K20PR L11S Thread Size Applicable Mode...

Page 86: ...f low pressure is used use a ultra fine 0 4mm iridium center electrode and the spark gap is already set at the optimum distance If the electrode is damaged by gap adjustment or cleaning the spark plugs will not perform to their best Can the gap be adjusted Can I use any spark plug cleaners with the ...

Page 87: ...or Toyota D4 For Mitsubishi GDI VKB series VKB16 VKB20 VKB series Subaru Peugeot Citroën Nissan Renault Mitsubishi Mercedes Benz Toyota Isuzu etc Thread length is 26 5mm VKH series VKH16 VKH20 VKH22 VKH20Y VKH series Used primarily for cars Installation screw ø14XL19 Mark II Sunny Familia BMW Audi etc Mercedes Benz Mazda Ford etc VT series VT16 VT20 VT series Used for small cars Installation screw...

Page 88: ... 0 8 1 5 3 0 5 2 RC 5 V07 0 42511 05607 7 267700 0790 0 42511 02607 0 100676 3790 VT16 14 17 5 16 1 1 1 5 3 0 5 5 RC 5 V21 0 42511 05621 3 267700 2810 0 42511 02621 6 100676 5280 VT20 14 17 5 16 1 1 1 5 3 0 5 5 RC 5 V38 0 42511 05638 1 267700 4480 0 42511 02638 4 100676 5290 VXU22 12 19 16 0 9 1 3 2 8 5 0 RC 5 V08 0 42511 05608 4 267700 0800 0 42511 02608 7 100676 3800 VXU24 12 19 16 0 9 1 3 2 8 5...

Page 89: ...ing at 50km h on an automatic test device and accelerating at full throttle Improved Acceleration Through steady ignitability acceleration performance is greatly improved By welding a platinum tip to the ground electrode wear has been controlled to a significant extent in the Iridium Plus In addition to acceleration performance the life and durability of this plug has been increased to that of a p...

Page 90: ...acing Yoichi Ui Denso Sard Supra GT World s smallest 0 4mm diameter center electrode As of May 2004 On the circuit is where it makes the difference Reliability and Durability Borne Out by Race Results and Trusted by Riders like Azuma Ui and Matsudo Plug Regular race plug 0 8mm electrode 13 9 14 0 13 950 13 985 Time to reach 100km h s The data shown is from internal studies Also the Regular Racing ...

Page 91: ...y DENSO Japan Patent No 2727558 Compared to the nickel alloy used in conventional spark plugs the high melting point of platinum will reduce such problems as ground electrode melting and wear Also the 0 8mm platinum alloy is welded on and gapped without any bending reducing residual stress and increasing durability IAE01 has a 1 0mm square tip 0 8mm All Platinum Ground Electrode Electrode Shape Th...

Page 92: ...G 14 21 20 6 1 1 2 5 0 5 1 6 S 5 R54 0 42511 05754 8 267700 4820 New IRL01 31 ROTARY RX8 LEADING 14 21 20 6 1 1 2 5 0 5 1 6 S 5 R55 0 42511 05755 5 267700 4830 New IRT01 31 ROTARY RX8 TRAILING 14 19 20 6 1 1 2 5 0 5 1 6 S 5 R52 0 42511 05752 4 267700 4840 New IRT01 34 ROTARY RX8 TRAILING 14 19 20 6 1 1 2 5 0 5 1 6 S 5 R53 0 42511 05753 1 267700 4850 IA01 31 WITH DETONATION COUNTER 14 22 16 0 6 1 0...

Page 93: ...R BCP E R7233 14 19 16 BC E R7234 14 19 16 R BC E R7235 14 19 16 BC E R7236 14 19 16 R BC E R7237 14 19 16 BC E R7238 14 19 16 R BC E R7239 14 19 16 R BC E R7436 Ir 14 19 16 BC E SEMISURFACE R5883 14 19 16 R BC E SEMISURFACE R6690 14 26 5 16 R LFR R7437 Ir 14 26 5 16 R LFR R7438 Ir 14 12 7 20 6 B H R5525 14 12 7 20 6 B H R5530 14 21 5 20 6 R ROTARY R6725 14 21 5 20 6 R ROTARY R7420 Ir 14 21 5 20 6...

Page 94: ... slant ground electrode type If your car is turbo tuned where the turbine has been replaced and the boost pressure is above 1 2 to 1 3kg cm2 an Iridium Racing 01 type is needed Also if a NA tuned engine with comparatively high vibration 4 cylinders is to be raced over long distances switching to this type can increase the reliability of the ground electrodes Iridium Racing 02 Type The 02 type flat...

Page 95: ...t now it goes below 550rpm and stalls The revolutions increase smoothly and acceleration is good during driving Why is this Frequently for older vehicles the ignition system has degraded and it is sometimes not possible to see the full effect of Iridium Power In this case the spark gap should be adjusted from 1 1mm to 0 8mm Also in the VK series there is the VK20Y plug where the gap has been prese...

Page 96: ...ot being available from the coil For improved ignitability the low heat range Iridium Power plugs have a spark gap of 1 1mm and in vehicles with a significantly weakened electrical system this may result in symptoms such as rough idling and lack of power Adjusting the spark to between 0 8 and 1 0mm should solve this problem However because the center electrode is extremely thin please have this ad...

Page 97: ...cide our product specifications keeping in mind every customer Are plugs such as VUH27D and VK24PRZ11 for Honda vehicles available as Iridium Tough plugs Will they last 100 000km Also can Iridium Power be substituted here Plugs for 2 wheel vehicles with a V in the part number have a platinum tip welded to the ground electrode the same as in 4 wheel vehicles They have more durability than Iridium P...

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Page 100: ...ation and Q A are provided Basic plug information and Q A Appropriate information retrieval Movie Master brochure data download Updated information Introduction of the IRIDIUM POWER series PR space http www globaldenso com PLUG DENSO PLUGS site English version opened Printed in Japan 100 recycled paper 10018C 006 5X 5A ...

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