systems, though comparatively light, adequately resist high  temperatures, corrosion, and vibration to provide long,  trouble-free operation with minimum maintenance. There are two general types of exhaust systems in use on  reciprocating aircraft engines: the short stack (open) system  and the collector system. The short stack system is generally  used on nonsupercharged engines and low-powered engines  where noise level is not too objectionable. The collector system  is used on most large nonsupercharged engines and on all  turbosupercharged engines and installations on which it would  improve nacelle streamlining or provide easier maintenance in  the nacelle area. On turbosupercharged engines, the exhaust  gases must be collected to drive the turbine compressor of the  supercharger. Such systems have individual exhaust headers  that empty into a common collector ring with only one outlet.  From this outlet, the hot exhaust gas is routed via a tailpipe  to the turbosupercharger that drives the turbine. Although the  collector system raises the back pressure of the exhaust system,  the gain in horsepower from turbosupercharging more than  offsets the loss in horsepower that results from increased back  pressure. The short stack system is relatively simple, and its  removal and installation consists essentially of removing and  installing the hold-down nuts and clamps. Short stack systems  have limited use on most modern aircraft. In  Figure 3-38,  the location of typical collector exhaust  system components of a horizontally opposed engine is  shown in a side view. The exhaust system in this installation  consists of a down-stack from each cylinder, an exhaust  collector tube on each side of the engine, and an exhaust  ejector assembly protruding aft and down from each side of  the firewall. The down-stacks are connected to the cylinders  with high temperature locknuts and secured to the exhaust  collector tube by ring clamps. A cabin heater exhaust shroud  is installed around each collector tube.  [Figure 3-39] The collector tubes terminate at the exhaust ejector openings  at the firewall and are tapered to deliver the exhaust gases  at the proper velocity to induce airflow through the exhaust  ejectors. The exhaust ejectors consist of a throat-and-duct  assembly that utilizes the pumping action of the exhaust  gases to induce a flow of cooling air through all parts of the  engine compartment (augmenter tube action). Figure 3-40  shows the exhaust collector ring installed on  a 14-cylinder radial engine. The collector ring is a welded  corrosion-resistant steel assembly manufactured in seven  sections, with each section collecting the exhaust from two  cylinders. The sections are graduated in size.  [Figure 3-41] The small sections are on the inboard side, and the largest  sections are on the outboard side at the point where the tailpipe  connects to the collector ring. Each section of the collector  ring is bolted to a bracket on the blower section of the engine  and is partly supported by a sleeve connection between the  collector ring ports and the short stack on the engine exhaust  ports. The exhaust tailpipe is joined to the collector ring by a  telescoping expansion joint, which allows enough slack for the  removal of segments of the collector ring without removing  the tailpipe. The exhaust tailpipe is a welded, corrosion- resistant steel assembly consisting of the exhaust tailpipe and,  on some aircraft, a muff-type heat exchanger. 3-23 Figure 3-38.  Location of a typical collector exhaust system. Figure 3-39.  A cabin heater exhaust shroud. Radial Engine Exhaust Collector Ring System Upper sheet jacket Lower sheet jacket Heat exchanger collector tube