Table of Contents

Introduction 5 Using this book & essential information 6 Chapter 1: Terminology 8 'Duration' 8 'Phasing' 10 'Duration' and 'Phasing' 10 'Valve lift' 11 'Camshaft lobe lift' 11 'Overlap' 12 'Lift rate' 12 'Valve clearance' 12 Mechanical versus hydraulic camshaft profiles 13 'Full lift' 13 'Full lift timing' 14 'Piston to valve clearance' 14 Chapter 2: Choosing the right amount of duration 16 270 Degrees of duration 17 280 Degrees of duration 17 290 Degrees of duration 17 300 Degrees of duration 18 310 Degrees, or more, of duration 18 Camshaft duration and rpm ranges 19 Pushrod overhead valve engines 19 Single overhead camshaft engines 21 Two valve twin overhead camshaft engines 21 Four valve twin overhead camshaft engines 21 Chapter 3: Checking camshafts 22 Camshaft straightness 24 Camshaft journal condition 25 Lobe accuracy 25 Chapter 4: Camshaft timing principles 27 Checking TDC 28 Marking the crankshaft damper/ pulley 29 Camshaft timing check using the full lift position 31 -------------------------------------------------------------------------------- Chapter 5: Camshaft problems 34 Engineering tolerances. 34 Camshaft specifications 34 Lobe Phasing 35 Re-ground camshafts 35 Lack of power (camshaft at fault?) 37 Chapter 6: Timing procedure - cam-in-block engines 38 Checking for full lift using the lifter 39 Finding 'true' top dead centre 39 Checking full lift via lifter movement 40 Checking full lift via rocker arm/valve retainer movement 43 Chapter 7: Camshaft timing procedure - S.O.H.C. engines 45 Chapter 8: Camshaft timing procedure - T.O.H.C. engines 48 Two valve per cylinder engines 48 Four valve per cylinder engines 48 Chapter 9: Engine testing 56 Rolling road 56 Track/road testing 57 Drag strip 58 Engine dyno 58 Complementary SpeedPro books 59 Index 64

About the Author

Des Hammill is an engineer and professional race engine builder with many years experience.