Lycoming Flyer - Aircrafts sales, engines repair, spare parts

Comparing various parts and accessories used in engine modelswhich some individuals have considered to be much the same,illustrates the differences. Although some Lycoming modelsare closely related, this cannot be assumed. A review of theengineering parts list for each engine model by a knowledgeableindividual is the only sure way of establishing similarities anddifferences. Those who may have been taken in by the myth thatall Lycoming engines of a particular displacement are very muchthe same are now armed with a better knowledge.There are many who look for an aircraft engine on the openmarket. While there is nothing wrong with this approach toacquiring a needed power plant, it sometimes results in anunfortunate choice. Perhaps a little information on the possiblepitfalls may help to reduce the number of bad choices.Individuals working on home-built aircraft may be particularlysusceptible to this type of error. At Lycoming, there have beenmany calls from people who grabbed an engine that seemed tobe an exceptionally good deal — only to find that this “engine oftheir dreams” would not fit into the aircraft they are building.Consider the circumstances which lead to these problems. Theperson looking for an engine is usually building an aircraft fromhis own plans or from a kit supplied by a kit manufacturer.As the airframe begins to take shape, obtaining a suitable enginemay be reason for some concern and anxiety. When a Lycoming0-320, 0-360 or other engine with appropriate horsepower ratingis found, there is a temptation to buy now and ask questions later.This could be a serious mistake.The article “Low-time Engine May Not Mean Quality andValue” that appears next in this booklet explains that old engineswith low time are frequently affected by internal rust and corrosion.Any engine that is not used frequently should be preserved.The condition of the engine is just one of the items to be consideredwhen acquiring a power plant in the resale market.Other mistakes often involve the engine model. Unfortunately,there are those who believe that all Lycoming 0-320 enginemodels are alike, and that all Lycoming O-360 engine modelsare also very similar. The Lycoming-certified aircraft enginelist shows 58 O-320 models and 51 0-360 models. While theseengines may be similar in many respects, it is the differences thatare likely to cause installation problems. These differences shouldbe well understood before an engine is purchased.What are the differences that may cause installation problems?The engine-mounts should be considered. Older engine modelswere built with conical mounts that make installation somewhateasier, but which do not dampen engine vibration as well. Withvery few exceptions, engines certified during the l970s and 1980shave dynafocal mounts.Although the type of engine mount is not likely to be aserious problem, the shape of the sump, the location of thecarburetor or an engine-mounted oil filter may result in airframeinterference which makes installation of a particular enginemodel difficult or impossible. Some aircraft, for example, do nothave enough space between the engine and the fire-wall for anengine-mounted oil filter. In the case of an engine with asingle-unit dual magneto, there is nothing that can be done sincethe filter is a required part of the engine design. All Lycomingengines with two individual magnetos can be configured tooperate without an oil filter. Should an oil filter and the spaceneeded to remove it be the only problem in adapting this type ofengine to an airframe, the filter and adapter can be removed andan oil pressure screen housing can be installed instead. Should thisstep be necessary, the recommended oil change interval is reducedto 25 hours. A second option would involve removing the filterfrom its standard location and mounting it remotely.Engine to firewall is not the only area where space may be limited.The sump is often tailored in size and shape to meet the requirementsfor a particular airframe. For that reason, the home-buildermay find that some engine models will not fit the plane being builtbecause of interference. As if this were not enough to be concernedabout, the carburetor or fuel injector location must also beconsidered. These fuel-metering devices are frequently mountedunder the engine in an updraft configuration, but there are alsofront- and rear-mounted configurations. Some engine models areequipped with horizontal carburetors. All of these variations inmodel, may have an effect on engine/airframe fit.Another error in choice which occurs all too frequently is thepurchase of an engine originally designed for a high-wing aircraftwhen the builder has a low-wing design under construction. Thelow wing needs a fuel pump, but the high wing usually deliversfuel to the carburetor by gravity. In most cases, a fuel pump cannotbe added to the engine because the drive mechanism was not builtin during engine manufacture, and the accessory housing was notmachined to allow mounting of a fuel pump.As a result of contacts with individuals who have made enginepurchases for their aircraft, we know that the variations inengine configuration outlined in this article have resulted inproblems. The purpose of bringing these issues to the attentionof Flyer and Key Reprints readers is to help them avoidmaking the same mistakes others have made. If a particularengine model has been recommended by a kit manufacturer, itis best to search out that model. Although similar, other enginemodels may not meet your needs.Choosing the right engine is often a difficult decision thatultimately could affect the success of the home-built aircraft.Finding a used engine is tricky and, as we have already covered,the builder has to keep a lot of factors in mind such as sizeand configuration.Lycoming recognizes that home-built aircraft builders aremechanically inclined and technically trained and are alwaysstriving for more options and new technologies. Therefore,Lycoming has recently launched several new product lines thatoffer builders the “Power of Choice.”Lycoming works very hard with Experimental AircraftManufacturers to ensure that they have power plants for theircustomers. Lycoming currently offers fully assembled CertifiedL y c o m i n g F l y e r 2 9