Porting heads is an art and science. It takes a craftsman's touch to shape the surfaces of the head for the optimal flow characteristics and the best performance. Porting demands the right tools, skills, and application of knowledge. Few other engine builders have the same level of knowledge and skill porting engine heads as David Vizard. All the aspects of porting stock as well as aftermarket heads in aluminum and cast-iron constructions are covered. Vizard goes into great depth and detail on porting aftermarket heads. Starting with the basic techniques up to more advanced techniques, you are shown how to port iron and aluminum heads as well as benefits of hand and CNC porting. You are also shown how to build a high-quality flow bench at home so you can test your work and obtain professional results. Vizard shows how to optimize flow paths through the heads, past the valves, and into the combustion chamber. The book covers blending the bowls, a basic porting procedure, and also covers pocket porting, porting the intake runners, and many advanced procedures. These advanced procedures include unshrouding valves, porting a shortside turn from the floor of the port down toward the valve seat, and developing the ideal port area and angle. All of these changes combine to produce optimal flow velocity through the engine for maximum power.
Product Details
ISBN-13: 9781934709641
Media Type: Paperback
Publisher: CarTech
Publication Date: 02-23-2012
Pages: 160
Product Dimensions: 8.40(w) x 10.90(h) x 0.40(d)
About the Author
David Vizard is a revered engine builder, technical writer, and author. In fact, he has authored more than 30 highly respected engine building and automotive books, penned about 4,000 magazine articles, and contributed scores of web pieces to popular sites. Often referred to as Vizard the Wizard, his work is often the subject of blogs and editorial pieces in popular automotive magazines. Currently, he owns and runs MotorTec Magazine in Charlotte, North Carolina.
Table of Contents
Table of Contents
Table Of Contents: About the Author 4 Acknowledgments 6 Introduction 7 Chapter 1: What It Takes to Make Power 14 Point of Maximum Flow 15 Seat and Port Priorities 15 Do You Need a Flow Bench? 16 Chapter 2: Flow Testing Procedures 18 The Standard Pressure Drop 18 Real-World Test Pressures 21 Corrections 21 Floating Pressure-Drop Testing 22 Intake Fixation? 23 Flow Efficiency 24 Chapter 3: A Flow Bench—Build or Buy 25 A Rethink on Matters 26 Current Conclusions 28 Flowing the Exhaust 28 Establishing the Numbers 29 Summary 31 Budget Computerization 31 Audie Technology 32 Performance Trends 35 Other Bench Sources 37 Chapter 4: Wet-Flow Testing 38 Wet-Flow Testing—What’s it Worth? 38 Six Wet-Flow Mistakes to Avoid 40 Chapter 5: Porting Aftermarket Heads 47 Air Flow Research 48 Dart 49 Edelbrock 51 EngineQuest 54 Racing Head Service 54 Trick Flow Specialties 55 Chapter 6: Porting Tools, Consumables and Safety 67 Eye and Lung Safety 67 Grinders—Air or Electric 68 Carbide Cutters 69 Support Porting Tools 69 Sourcing Consumable Supplies 74 Chapter 7: Five Golden Porting Rules 79 Rule Number 1 80 Rule Number 2 80 Rule Number 3 80 Rule Number 4 81 Rule Number 5 81 Chapter 8: Developing Functional Ports 82 Valve Seat Forms 82 Working Valve Seat Shapes 83 Alternative Seat Angles 84 Seats on Valves 87 Valve Shapes 87 Clearances and Temperatures 89 Cutting Valve Seats 91 Chapter 9: Valve Shrouding 96 Practical De-shrouding 97 Chapter 10: Developing Functional Heads 100 Optimizing Cylinder Head Airflow 100 Valve and Flow 101 Ports 101 Cross-Sectional Area 103 Port Velocity 105 Applied Basic Porting 108 Compression Increase 113 Modified 170s on the Dyno 113 The Virtual Flow Bench 114 Chapter 11: The Combustion Process 124 Defining Combustion 124 Combustion Efficiency 126 British Touring Car Championship Year 129 Finally: The Chambers 131 More Combustion Curiosities 132 Atomization Optimization 133 Thermal Barriers 135 Swirl and Quench 135 More Thermal Management 137 Small Crevice Volume—Big Consequences 138 Conclusions 143 Chapter 12: Maximizing Compression Ratio 144 Thermodynamics Made Easy 146 Dynamic Compression 148 Intake- to Exhaust-Valve Ratios 153 Containing the Pressure 157 Source Guide 158