It can be argued that the aircraft engines 'bottom end, i.e.. the crankcase. Crankshaft, camshaft. accessory section, etc.-is among the least understood parts of a modern light plane. This volume of the Light Plane Maintenance Library attempts to change that. This book is a companion to the first volume of the series. FWF: The Top End. As such it is intended to broaden the operator's understanding of firewall-forward phenomena other than those involving values. pistons and cylinder barrels. When it comes to firewall-forward components, knowledge is indeed power. Here the editors will give you that knowledge by examining three major areas of concern and consideration for greater engine life and better performance. Part 1: "Anticipating Trouble" emphasizes the old adage tht an ounce of prevention is worth, in this case, several hundred pounds of cure. You will discover that there is no single, easy way to keep tabs on an engine's health because no one technique is foolproof. The key is to combine different techniques. You will learn how to judge engine health through a variety of indicators, how to pinpoint the causes of low power, how to cope and conquer high oil consumption and diagnose firewall-forward vibration problems. Part 2: "Understanding Power-Augmenting Systems" is a subject that is rarely fully addressed, but one of great interest to owners and operators of high performance aircraft: modern light plane turbocharging. Part 3: "Getting the Most Engine Life" is a real money saver, if you know what you are doing. Here you will get a rundown of the risk factors in TBO busting in an engine-by-engine assessment. But, sooner or later, all engines need a major overhaul. This chapter will give you the facts before you commit to the rebuild, including 20 important questions to ask of a potential rebuild shop.