Knowledge gained from the experience of others is usually the easy way to learn. In the case of sticking valves that may damage an engine or cause it to fail, it is surely best if the knowledge is not acquired firsthand. The experience of others is related in the following paragraphs. One of the regional service managers here at the Lycoming factory indicated that his experience over the years...

Considering that the properly timed sequence of valve opening and closing is essential to efficient and reliable engine operation. Anytime those valves stick for any reason, it is a serious problem. Therefore, the purpose of this article is to provide our readers with some insight into this problem along with methods to help avoid it. The space between the continuously moving valve stem and its...

These are some of the more common questions asked at our service hanger: QUESTION: Do your new, rebuilt or overhauled engines require a break-in period that consists of cruise at low-power settings? ANSWER: Definitely not. Fly them as you would a high-time engine. In fact, so-called “slow” flying may have harmful effects. The rings may not seat properly resulting in higher than normal oil...

Airline deregulation has caused changes. Many aircraft powered by Lycoming reciprocating engines are being used in the commuter market. These aircraft operate under Part 135 of the Federal Air Regulations and generally have a regular schedule which must be maintained day after day. The engines of these aircraft, like those operated for individual or corporate transportation, are expected to reach...

We have firm evidence that engines not flown frequently may not achieve the standard expected overhaul life. Engines that are flown occasionally deteriorate much more rapidly than those that fly consistently. Pilots have asked, “What really happens to an engine when it’s flown only one or two times per month?” An aircraft engine flown this infrequently usually accumulates rust and corrosion...

Paul McBride, a former Lycoming employee widely known as “Mr. Lycoming,” likes to tell the story of the Mooney owner whose preowned Lycoming IO-360-powered single wouldn’t get up to the specified maximum RPM setting of 2700. After an adjustment at a shop, the engine did obtain 2700 RPM on the gauge, but the power plant failed in flight shortly thereafter. After a safe emergency landing, Canadian...

The flow of oil through a Lycoming reciprocating aircraft engine is known to be a necessary function during the operation of the engine. Pilots are often not at all concerned about how this function occurs, as long as the oil pressure and oil temperature indicators show a proper reading. A&P mechanics, on the other hand, often need to know how the system works and what parts control the flow of...

Even the “pros” of our industry admit they need to be reminded from time to time of the basics of General Aviation maintenance. Therefore to review, the term maintenance means the inspection, overhaul, repair, upkeep and preservation of an aircraft and engine, including the replacement of parts, according to the FAA. The owner/operator is responsible for the proper maintenance of his aircraft and...

People who fly should be concerned about the reliability of the aircraft they fly and the engine that powers that aircraft. One key to reliability is regular maintenance by a knowledgeable A & P mechanic. “Knowledgeable” does not necessarily mean the mechanic must have every detail of every job locked in his or her memory. It does mean that the individual should have relevant information readily...