The Sports Car Engine Its Tuning and Modification the Sports Car Engine Its Tuning and Modification

Total Page:16

File Type:pdf, Size:1020Kb

The Sports Car Engine Its Tuning and Modification the Sports Car Engine Its Tuning and Modification THE SPORTS CAR ENGINE ITS TUNING AND MODIFICATION THE SPORTS CAR ENGINE ITS TUNING AND MODIFICATION * COLIN CAMPBELL M.Sc., A.M.I.Mech.E., M.S.A.E. SPRINGER-SCIENCE+BUSINESS MEDIA, B.V. '9 63 © COLIN CAMPBELL 1963 ORIGINALLY PUBLISHED BY CHAPMAN & HALL LTD. 1963 SOff COVER REPRINT OF THE HARDCOVER 1ST EDITION 1963 SBN 412 07470 2 ISBN 978-0-412-02740-6 ISBN 978-1-4899-7204-0 (eBook) DOI 10.1007/978-1-4899-7204-0 TO MY FATHER who tuned motor cars before tuning was invented Show me the mechanic who pops out his chest and announces 'I don't need any fancy gadgets to tune a car, all I need is to listen to the engine.' Show me this man and I will show you a }!_yjJer-ep,otistical DOPE. ToM McCAHILL Preface I HAVE ATTEMPTED to write in one volume a textbook on the theory of automotive engine tuning, always with a bias towards the more highly developed type of engine as used in the modern sports car. Engine tuning is treated in its two aspects, basic tuning and super­ tuning, i.e. the modification of a stock engine to increase the power output. A supertuned engine operates with a tighter margin of safety than a stock engine and a loss of basic tune can soon lead to over­ heating, even to catastrophic failure. With this in mind the major part of the book concentrates on the theory and practice of basic tuning. Chapters are devoted to the ignition system, to carburettors and to the methods used in 'trouble-shooting'. All of this is of value to the owner-mechanic, the garage man and the trainee racing mechanic. Supertuning is the subject of Chapters Nine to Thirteen. Here I attempt to take the magic out of supertuning. So many of the latest methods used in the British, German, Italian and American tune-shops are based on knowledge obtained in the engine labora­ tories of universities, colleges and commercial research institutions throughout the world. Much of this knowledge is available to all of us, if we take the trouble to ferret it out. From time to time throughout the book the reader will see references to experimental work of this kind. The final chapter is on the mechanics of modifica­ tion. By providing practical hints on the ways and means of engine modification this chapter should help to preserve the balance between theory and practice. I am especially grateful to the editor of Sporting Motorist for permission to reproduce certain material used in Chapters Four, Five and Six, which appeared originally in that excellent journal as a series of articles on carburettor tuning. CoLIN CAMPBELL Racine, Wisconsin, U.S.A. vii Contents Preface vii CHAPTER ONE General Principles TUNING FOR PEAK EFFICIENCY AND POWER; \-\'here does the power go? The energy in the fuel. Cycle efficiency losses. Combustion losses. Transmission losses. THE PENALTY OF POOR TUNE, SUPER­ TUNING: Making it breathe; make it efficient; making it reliable. CHAPTER TWO Instruments 17 TuNING INSTRUMENTS; The dynamometer. Garage instruments: tachometer; vacuum gauge; compression pressure gauge; fuel pressure gauge; stop-watch; voltmeter and ammeter. SPECIALIST INSTRUMENTS. Battery tester; ignition timing light; distributor analyser; tach-dwell meter; coil tester; condenser tester; plug tester; exhaust gas analyser; stroboscope; cathode ray oscilloscope. CHAPTER THREE The Ignition System 42 Ignition requirements. The primary circuit. The secondary circuit. Secondary voltage variations. The phenomena of the spark. Sparking plug and contact breaker gaps. Dwell angle. Ignition timing. Sparking plugs. MAGNETOS: principles; types; care and maintenance. CHAPTER FOUR Mixture Formation, Distribution and Carburation 59 The mixture. The boiling point range. Mixture and power. Distribution. Formation of the mixture. Manifold design. Pressure losses by distribution. THE MIXTURE REQ.UIREMENTS OF THE ENGINE; Starting and cold-running; idling; part-throttle operation; full throttle; acceleration. CHAPTER FIVE Variable Choke Carburettors 74 THE S.U. CARBURETTOR: Starting; idling; full throttle and cruis­ ing; acceleration. The HD type. The HS type. Tuning the S.U. carburettor. Vacuum gauge technique. Multiple carburettors. Tuning after modification. THE S.U. TWIN-CHOKE CARBURETTOR. IX X CONTENTS CHAPTER SIX Fixed Choke Carburettors 91 WoRKING PRINCIPLES: Mixture compensation; starting; idling; full throttle; acceleration. THE ZENITH: Series VN; Series W. THE SoLEX: Type 32 Bl; Type B 28 ZIC-2; Type C. 35 APAI-G. TuNING THE SoLEX. Tuning after modification. THE WEBER: the auxiliary venturi. The Type DCO. Tuning the \Veber. CTTA PTER SEVEN Testing and Tuning 129 The Importance of Testing. TESTING: The 11 Tests: initial road­ test; compression test; plug test; vacuum reading; battery test; coil and starter voltage; coil and condenser tests; contact breaker tests; fuel pump tests; mixture strength readings; valve clearances. TUNING: Tuning operations: valve clearance setting; sparking plugs; distributor; ignition timing; carburettors; final road-test. C:IL\PTER EICIIT Trouble-Shooting 149 Fault-finding with the vacuum gauge: valve trouble; induction leaks; broken piston rings; defective exhaust system. A short catalogue of troubles: bad starting; low speed misfires; high-speed misfire; overheating; fuel pump troubles. C:IIAPTER NINE Combustion Efficiency 170 THE BASIC PRINCIPLES OF SUPER TUNING: Combustion efficiency. Mechanical efficiency. Friction and pumping losses. The com­ pression ratio. Abnormal combustion. Knock. Other combustion abnormalities: rumble; pre-ignition; running-on. Combustion chamber shape: bath-tub head; wedge head; hemispherical head; ovrrht"ad inlet, side exhaust head. CHAPTER TEN Volumetric Efficiency 192 Definition. How to Improve Volumetric Efficiency. THE INDUC­ TION PROCESS: Inlet valve timing. Overlap. INLET VALVE AND THROAT DESIGN: The air flow rig. Flow calculations. Mean gas velo· city at valve throat. Mean gas velocity at valve seat. Carburettor venturi size. Valve seats. Valve throat and port design. Venturi ports. Curved ports. THE EXHAUST PROCESS: Exhaust valve si:te. EXHAUST VALVE THROAT AND PORT SHAPE. CONTENTS Xl CHAPTER ELEVEN Special Techniques 223 MuLTI-CARBURETTORs: One choke per cylinder. Experimental measurements. Recommended pipe lengths. PETROL INJECTION: Port injection systems; Rochester/Corvette; Lucas/Jaguar; Mer­ cedes Benz 300 SL. THE INTAKE AIR: Cold air intakes. .Forward ram intakes. RAMMING EXHAUST PIPES: Branched exhaust pipes. NEW IGNITION TECHNIQ.UES: Transistorised systems; electro-mag­ netic systems; piezo-electric systems. CHAPTER TWELVE Cams and Blowers 254 SPECIAL CAMSHAFTs: Factory options and re-grinds. The cam profile. The actual valve motion. Spring surge. Cam-face wear. When to fit a high-lift camshaft. BLOWERS: The mechanics of supercharging: Vane type; Roots type; Centrifugal type. SuPER­ CHARGER TUNING TIPS: Heat rejection; Blowing through the car­ burettor; Carburation for blowing; The drive. TuRBOCHARC11NG: Corvair; Oldsmobile. CHAPTER THIRTEE:\" The Mechanics of Modification 275 CYLINDER HEAD WORK: Compression ratios and how to change them. Measuring the clearance volume. High compression pistons. Machining methods. Work on the ports. INCREASING THE LIFE OF COMPONENTS: Crack detection. Shot peening. Balancing. WoRK ON THE VALVE GEAR: Push-rods. Tappets. Rockers. Springs. CONNECTING RODS, PISTONS. SPARKING PLUGS. EXHAUST VALVE MATERIALs: Exhaust valve troubles. APPENDICES 1. Special Camshafts 298 2. Champion Engineering Racing Division Heat Range Comparison Chart 310 3. Suggested Maximum Torque Values 312 4. S.A.E. Horse Power 314 Index 317 List of Plates (The plates are inserted as a section between pages 148-149) I. Multi-carburettor synchronising gauge marketed by Rally Engineering The Rally Engineering device in use on a Sunbeam Alpine 2. Normal plug appearance Dirty plug 3. Oily plug Overheated plug 4. Broken insulator nose Flashover 5. Aluminium alloy head for the 'B' Series B.M.C. engine A special rocker cover 6. Kit for Stage-2 conversion of the Austin-Healey 'Sprite' and M.G. 'Midget' Cast alloy cold air box for the 'Sprite' 7. Twin-choke Weber carburettor kit for Triumph Herald The TR3 and TR4: racing engines 8. Exhaust extractor devices: the Alextractor S.A.H. oil cooler kit 9. The Judson supercharger kit for the 'Sprite' With the fitting of a Judson supercharger kit the Mercedes Benz l90SL is transformed into a 'tiger' 10-15. The case history of a successful 3-litre Austin-Healey 16. The component parts of the Lucas electronic ignition system for an 8-cylinder engine with fixed ignition timing xii .
Recommended publications
  • Engine Components and Filters: Damage Profiles, Probable Causes and Prevention
    ENGINE COMPONENTS AND FILTERS: DAMAGE PROFILES, PROBABLE CAUSES AND PREVENTION Technical Information AFTERMARKET Contents 1 Introduction 5 2 General topics 6 2.1 Engine wear caused by contamination 6 2.2 Fuel flooding 8 2.3 Hydraulic lock 10 2.4 Increased oil consumption 12 3 Top of the piston and piston ring belt 14 3.1 Hole burned through the top of the piston in gasoline and diesel engines 14 3.2 Melting at the top of the piston and the top land of a gasoline engine 16 3.3 Melting at the top of the piston and the top land of a diesel engine 18 3.4 Broken piston ring lands 20 3.5 Valve impacts at the top of the piston and piston hammering at the cylinder head 22 3.6 Cracks in the top of the piston 24 4 Piston skirt 26 4.1 Piston seizure on the thrust and opposite side (piston skirt area only) 26 4.2 Piston seizure on one side of the piston skirt 27 4.3 Diagonal piston seizure next to the pin bore 28 4.4 Asymmetrical wear pattern on the piston skirt 30 4.5 Piston seizure in the lower piston skirt area only 31 4.6 Heavy wear at the piston skirt with a rough, matte surface 32 4.7 Wear marks on one side of the piston skirt 33 5 Support – piston pin bushing 34 5.1 Seizure in the pin bore 34 5.2 Cratered piston wall in the pin boss area 35 6 Piston rings 36 6.1 Piston rings with burn marks and seizure marks on the 36 piston skirt 6.2 Damage to the ring belt due to fractured piston rings 37 6.3 Heavy wear of the piston ring grooves and piston rings 38 6.4 Heavy radial wear of the piston rings 39 7 Cylinder liners 40 7.1 Pitting on the outer
    [Show full text]
  • Ignition System
    IGNITION SYSTEM The ignition system of an internal combustion engine is an important part of the overall engine system. All conventional petrol[[1]] (gasoline)[[2]] engines require an ignition system. By contrast, not all engine types need an ignition system - for example, a diesel engine relies on compression-ignition, that is, the rise in temperature that accompanies the rise in pressure within the cylinder is sufficient to ignite the fuel spontaneously. How it helps It provides for the timely burning of the fuel mixture within the engine. How controlled The ignition system is usually switched on/off through a lock switch, operated with a key or code patch. Earlier history The earliest petrol engines used a very crude ignition system. This often took the form of a copper or brass rod which protruded into the cylinder, which was heated using an external source. The fuel would ignite when it came into contact with the rod. Naturally this was very inefficient as the fuel would not be ignited in a controlled manner. This type of arrangement was quickly superseded by spark-ignition, a system which is generally used to this day, albeit with sparks generated by more sophisticated circuitry. Glow plug ignition Glow plug ignition is used on some kinds of simple engines, such as those commonly used for model aircraft. A glow plug is a coil of wire (made from e.g. nichrome[[3]]) that will glow red hot when an electric current is passed through it. This ignites the fuel on contact, once the temperature of the fuel is already raised due to compression.
    [Show full text]
  • Owner's M Anua
    OWNER’S M ANUA Thank you for purchasing the HONDA GV400 vertical engine. If any trouble should develop with your unit, consult the dealer from whom you purchased it. i @ IWNOA MOTOR CO., LTD. iggo is!@ - _~- _ .___ _II tamw * To prevent fire hazards and to provide adequate ventilation, keep the engine at least 3 ft away from buildings and other equipment, during operation. Ir Do not place flammable objects, such as, gasoline, matches, etc., close to the engine while it is running. * Refuel in a well ventilated area with the engine stopped. Gasoline is flammable and explosive under certain conditions. * Do not smoke or allow flames or sparks where the engine is refueled or where gasoline is stored. * Do not overfill the tank. There should be no fuel in the filler neck. Make sure that the filler cap is closed securely. * If any fuel is spilled, make sure the area is dry before starting. * Operate the engine on a level surface to prevent fuel spillage. * This engine is not equipped with a spark arrester, and operation may be illegal in some areas. Check local laws and regulations before operation. * Exhaust contains poisonous carbon monoxide gas. Avoid inhalation of exhaust gases. Never run the engine in a closed garage or confined area. Every 100 operating Hrs. First 20 operating Hrs. I Every 20 operating Hrs. CHANGE ENGINE OIL . CLEAN AIR CLEANER . CHANGE ENGINE OIL l CLEAN SPARK PLUG AND CHECK GAP Breaker type CD1 type L 0.6 - 0.7 mm 0.9 - 1.0 mm ImaffKAwj *JE type 1 (0.024 - 0.027 in) (0.035 - 0.039 in) .C(LJ$Jji@ \/-- Cycle, valve arrangement 4Stroke, side valve * For replacement, use BMdA or l BPMdA or BPMRdA Displacement cm3 (cu in) 406 (28.1) BMRdA spark (NGK) plug WW Max.
    [Show full text]
  • Autosaver (PDF)
    P881-220840 EPA-AA-TBB-511-81-3 I EPA Evaluation of the Autoraver under Section 511 of the Motor Vehicle Information and Coat Saving8 Act Edward Anthony Barth May, 1981 Test and Evaluation Branch Emirrion Control Technology Division Office of Mobile Source Air Pollution Control Environmental Protection Agency -2- 6560-26 EPA-AA-TEB-511-81-3 ENVIRONMENTAL PROTECTION ACENCY [40 CFR Part 610) FUEL ECONOHYRETROFLT WVLCES Announcement of Fuel Economy Retrofit Device Evaluation for “Autosaver” AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of Fuel Economy Retrofit Device Evaluation. s UMARY : This document annwnces the conclusions of the EPA evaluation of the “Autosaver” device under provisions of Section 511 of the Motor Vehicle Information and Cost Savings Act. -3- BACKGROUND LNFORMATZON: Section 511(b)(l) and’ Section 511(c) of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 2011(b)) requires that: 1 fi * (b)(l) “Upon application of any manufacturer of a retrofit device (or ’i . prototype thereof), upon the’ requast of the Federal Trade Commission I pursuant to subsection (a), or upon his own motion, the EPA Administrator shall evaluate, in accordance with rules prescribed under subsection (d), any retrofit device to determine whether the retrofit device increases fuel economy and to determine whether the <cpresentations (if any) made with respect to such retrofit devices are accurate.” (cl “The EPA Administrator shall publish in the Federal Register a summary of the results of all tests conducted under this section, together with the EPA Administrator’s conclusions as to - (1) the effect of any retrofit device on fuel ecor,orny; (2) the effect of any such device on emissions of air pollutants; and (3) any other information which the Admfnfstrator determines to be relevant in evaluatirg such device.” EPA publf shed final regulations establishing procedures for conducting fuel economy retrofit device evaluations on Elarch 23, 1979 144 FR 179461.
    [Show full text]
  • Bendix K Series Magnetos
    BENDIX K SERIES MAGNETOS SERVICE INSTRUCTIONS Scintilla Division, Bendix Aviation Corporation, Revised March 1956 DESCRIPTION The Bendix K series magnetos are high tension crankshaft magnetos designed for use on small one and two cylinder engines. They combine dependability with light weight and simplicity. The rotating magnet turns in close relation to a pair of laminated iron pole shoes, the outer ends of which carry the coil assembly. The pole shoes as well as the condenser are secured to a mounting flange which is a sturdy aluminum casting. Generally, the breaker incorporates a cam follower which is actuated directly by the engine crankshaft cam. However, on some single cylinder engines, the breaker is mounted remotely from the stator plate and magnet and a push rod is provided to actuate the breaker spring for separating the contact points. LUBRICATION On breaker assemblies incorporating a cam follower felt, apply one (1) drop of S.A.E. No. 60 oil to the cam follower felt when the magneto is installed and, after each 100 hours of operation, apply two (2) drops of S.A.E. No. 60 oil to the cam oiler felt. Blot off any excess oil with a clean cloth. Clean any excess grease from the cam. Inspect cam surface for rusting, pitting or scoring. All damaged cams should be replaced to reduce cam follower wear. Keep oil and grease away from the contact point surfaces. MAINTENANCE Ordinarily these magnetos will operate over extremely long periods of time without the need for adjustment or repair. However, if engine operating difficulties are experienced which appear to be caused by the ignition system, the magneto output should be checked to determine if this unit is functioning properly.
    [Show full text]
  • Simply Put, an Ignition System Activates a Fuel-Air Mixture to Create Energy
    Simply put, an ignition system activates a fuel-air mixture to create energy. The first ignition system to use an electric spark is thought to be Alessandro Volta’s toy electric pistol, ca. 1780. We’ve come a long way since that toy pistol! Today, the most commonly used ignition is the 4-stroke internal combustion system found in almost all vehicles, including your Air Cooled Volkswagen. In this newsletter, Mid America Motorworks takes a look at the evolution of the ignition system. Ignition – Why You Need A Spark Stroke 1: The piston’s Intake Valve opens to suck fuel and air In a 4-stroke internal combustion system, the spark is into the cylinder. where the magic happens. The spark ignites the air-fuel Stroke 2: The Intake Valve closes, capturing the fuel and air. mixture to create a burst of energy that moves your Beetle, The engine compresses the mixture, creating a large amount Bus, Ghia or Dune Buggy down the road. Just as the of potential energy. name implies, this happens in a sequence of 4 steps that • SPARK: When the piston reaches the top of the cylinder, continually repeat. the spark from the spark plug causes the mixture to explode. Camshaft Spark Plug Stroke 3: The explosion forces the piston back downward, Valve Spring releasing the potential energy as power. Cam Mixture In Stroke 4: The Exhaust Valve opens and the piston forces exhaust out of the cylinder. Exhaust Valve Cylinder Head Intake Valve Intake Valve Combustion Cooling Water Chamber Piston Cylinder Block Crankcase Connecting Rod Crankshaft Air Intake Compression Combustion Exhaust Emission The Main Components Distributor and thread farther into the engine’s combustion chamber.
    [Show full text]
  • CONTACT BREAKER POINTS Daichi Brand OEM Replacements
    GAUGES / BRUSHES / BREAKER POINT PLATES SHOP EQUIPMENT DAYTONA DIGITAL TACHOMETER CONTACT BREAKER POINT PLATE ASSEMBLIES This compact size tachometer indicates up to 19,990 RPM. Universal to both 2 and 4 strokes, and single to 8 cylinders. It memorizes the TOOLS highest RPM, and has a clock function. The body size is L 3”x W 1.4” x H .63. The window size is 1.3” x .6”. 22-1244 20-1482 20-1484 20-1483 HARD PARTS Made in Japan to O.E.M. specs. Available for the following models: 22-1244 Daytona Digital Tachometer HONDA KAWASAKI 20-1482 30200-300-154 20-1484 21135-011 CB750K/K1~K5 69-75 Z1/Z1A/Z1B-900 73-75 CB750K 76-78 KZ900A4/A5 76-77 CB750F Super Sport 75-78 KZ900B1 LTD 1976 WATER TEMPERATURE GAUGE KZ1000A1/A2 77-78 20-1483 30200-323-154 KZ1000B1/B2/B3 LTD 77-79 Note: Not for use in applications CB500/K1/K2 71-73 KZ1000C1/C2 Police 78-79 where maximum temperature CB550/K1/K 74-76 KZ1000D1 Z1R 1978 & FUEL CARB exceeds 212º F or 99.9º C. CB550F Super Sport 75-77 CB750A Automatic 76-78 CONTACT BREAKER POINTS Daichi brand OEM replacements. Made in Japan. Sold each. Note: Contact Breaker Point Application listed Next Page . CONTACT BREAKER POINTS X-REFERENCE IGNITION/ELECTRICAL Digital display gauge displays temperature up to 99.9º C (212º F.) Compact size mounts easily with velcro attachment. Made in Japan. HONDA 22-1128 Water Temperature Gauge K&L# MFG OEM # 22-1141 Water Temperature Sending unit only - for 22-1128 20-1460 Honda 30202-041-015 20-1461 Honda 30202-107-004 20-1481 Honda 30202-107-154 STARTER MOTOR & 20-1465 (RH) Honda 30203-286-004 RH Side ALTERNATOR BRUSHES 20-1466 (LH) Honda 30204-286-004 LH Side Manufactured in the USA.
    [Show full text]
  • Table of Contents 1 Battery
    Table of Contents 1 Battery................................................................................................................................................................................................................................1 1.1 Replacing Battery (Correct method).................................................................................................................................................................1 1.2 Replacing Battery (Alternate method)..............................................................................................................................................................1 1.3 Battery Spec.....................................................................................................................................................................................................1 1.4 See also............................................................................................................................................................................................................1 2 D-Jetronic...........................................................................................................................................................................................................................2 2.1 Issues...............................................................................................................................................................................................................2 2.2 See also............................................................................................................................................................................................................2
    [Show full text]
  • Symbols and Circuit Diagrams | Circuit Symbols
    500 | Symbols and circuit diagrams | Circuit symbols Symbols and circuit diagrams The electrical systems in vehicles contain Circuit symbols a wide array of electric and electronic devices for open and closed-loop engine- The circuit symbols shown in Table 1 are management systems as well as numer- a selection of the standardized circuit sym- ous comfort and convenience systems. bols relevant to automotive electrical sys- Only by using expressive symbols and tems. With a few exceptions, they conform circuit diagrams is it possible to provide to the standards of the International Elec- an overview of the complex circuits in trotechnical Commission (IEC). the vehicle’s electrical system. Circuit, The European Standard EN 60 617 schematic and terminal diagrams are a (Graphical Symbols for Electrical Circuit help during troubleshooting. They also Diagrams) corresponds to the interna- facilitate field installation of accessories, tional standard IEC 617. It exists in three and furnish support for trouble-free in- official versions (German, English and stallations and modifications on the French). The standard contains symbol vehicle’s electrical equipment. 1 Circuit diagram of an three-phase alternator with voltage regulator a WD+ B+ D+ wvu U D– DF B– b WB+D+ In addition to the symbol G for generator/alternator G, the circuit symbol also includes the symbols for the three 3 windings (phases) 3 U the star junction the diodes and the regulator U . B– Fig. 1 a With internal circuitry b Circuit symbols UAS0002-1E Robert Bosch GmbH (ed.), Bosch Automotive Electrics and Automotive Electronics, DOI 10.1007/978-3-658-01784-2, © Springer Fachmedien Wiesbaden 2014 Symbols and circuit diagrams | Circuit symbols | 501 elements, signs and, in particular, circuit cate the shapes and dimensions of the de- symbols for the following areas: vices they represent, nor do they show the General applications Part 2 locations of their terminal connections.
    [Show full text]
  • Table of Contents Table of Contents
    Table of Contents Table of Contents.......................................................................... 1 Terms and Conditions .................................................................. 5 Direct Sales and Value Added Dealers........................................................................... 5 Warranty ......................................................................................................................... 5 Repairs and Returns ........................................................................................................ 5 Pricing Policies ............................................................................................................... 5 Legal Disclaimer............................................................................................................. 6 Forward ......................................................................................... 7 3 A. Installing the TEC System .................................................... 9 A.1. How it All Works: The Two Pages You Need to Read ......................................... 9 A.2. Pre-Installation Checklist..................................................................................... 11 A.3. Mounting the Main Computer and DFU.............................................................. 12 A.4. Trigger Wheel and Sensor Installation................................................................. 14 A.4.a. Crankshaft Trigger Installation for 60(-2) Tooth Wheel............................... 14 A.4.b. Magnetic
    [Show full text]
  • Internal Combustion Engines
    Lecture-16 Prepared under QIP-CD Cell Project Internal Combustion Engines Ujjwal K Saha, Ph.D. Department of Mechanical Engineering Indian Institute of Technology Guwahati 1 Introduction The combustion in a spark ignition engine is initiated by an electrical discharge across the electrodes of a spark plug, which usually occurs from 100 to 300 before TDC depending upon the chamber geometry and operating conditions. The ignition system provides a spark of sufficient intensity to ignite the air-fuel mixture at the predetermined position in the engine cycle under all speeds and load conditions. 2 Introduction – contd. In a four-stroke, four cylinder engine operating at 3000 rpm, individual cylinders require a spark at every second revolution, and this necessitates the frequency of firing to be (3000/2) x 4 = 6000 sparks per minute or 100 sparks per second. This shows that there is an extremely short interval of time between firing impulses. 3 Introduction – contd. The internal combustion engines are not capable of starting by themselves. Engines fitted in trucks, tractors and other industrial applications are usually cranked by a small starting engine or by compressed air. Automotive engines are usually cranked by a small electric motor, which is better known as a starter motor, or simply a starter. The starter motor for SI and CI engines operates on the same principle as a direct current electric motor. 4 Ignition System -Requirements It should provide a good spark between the electrodes of the plugs at the correct timing The duration
    [Show full text]
  • Ignition System Types
    IGNITION SYSTEM TYPES Basically Convectional Ignition systems are of 2 types : (a) Battery or Coil Ignition System, and (b) Magneto Ignition System. Both these conventional, ignition systems work on mutual electromagnetic induction principle. Battery ignition system was generally used in 4-wheelers, but now-a-days it is more commonly used in 2-wheelers also (i.e. Button start, 2-wheelers like Pulsar, Kinetic Honda; Honda-Activa, Scooty, Fiero, etc.). In this case 6 V or 12 V batteries will supply necessary current in the primary winding. Magneto ignition system is mainly used in 2-wheelers, kick start engines. (Example, Bajaj Scooters, Boxer, Victor, Splendor, Passion, etc.). In this case magneto will produce and supply current to the primary winding. So in magneto ignition system magneto replaces the battery. Battery or Coil Ignition System Below figure shows line diagram of battery ignition system for a 4- cylinder petrol engine. It mainly consists of a 6 or 12 volt battery, ammeter, ignition switch, auto-transformer (step up transformer), contact breaker, capacitor, distributor rotor, distributor contact points, spark plugs, etc. Note that the Figure 4.1 shows the ignition system for 4-cylinder petrol engine, here there are 4-spark plugs and contact breaker cam has 4-corners. (If it is for 6-cylinder engine it will have 6-spark plugs and contact breaker cam will be a perfect hexagon). The ignition system is divided into 2-circuits : (i) Primary Circuit : It consists of 6 or 12 V battery, ammeter, ignition switch, primary winding it has 200-300 turns of 20 SWG (Sharps Wire Gauge) gauge wire, contact breaker, capacitor.
    [Show full text]