10 Ways to Increase Engine Life


By Richard “Zef” Zephro

In a perfect world, we would all replace our engines with factory new ones. I don’t know of anyone who wouldn’t want to do that. However, in the real world economics comes into play. Those who are not in the position of devoting their first born’s, college fund to an airplane engine must come up with alternate methods of keeping the engines running reasonably safely to at, or beyond, TBO (Time Between Overhaul).

Manufacturers come up with a suggested TBO based upon many variables. We have all seen the IO-360 move from as low as a 1200 hour TBO in the 1960’s to the 2,000 hours of today. Some of this was due to improvements (i.e. ½” valves and larger dowels, etc.), as well as proof from the field that the engine will make it to that point.

Manufacturers have taken an average from all engine uses including: flight school planes, Ag planes, planes in highly corrosive areas, their own fear of liability, and have thus arrived at the “magic” TBO number.

While It would be prudent to take that “suggested” number into account, it really depends on the engine’s health due to previous operation and maintenance techniques utilized in a particular engine application. in short, individual pilot technique may cause the actual life of the engine to shorten or lengthen this “average” life.

I have been involved in two Mooney’s I’ve owned over the years that got an engine overhaul, and both times I was told from the engine shop that it really was not needed due to the condition of the engine at teardown.

The difference between this and most reasons why the Continental in the 231 needs a top about half the time is:

– Operational techniques of the pilot,
– The average altitude flown
– Maintenance practice

In my business, I have the opportunity to fly with pilots from all walks of life, and I must tell you, that a good majority of pilots I’ve flown with do not know how to properly operate an aircraft engine so as to increase its longevity. I see the ham-handed ones jam the throttle in at takeoff. I see others yank the power off when needed without regard to shock cooling. Others fly them at high temps without doing anything to change that. Others fly the Lyc’s at lower RPM’s thinking that they will add to engine life. Still others taxi a short distance from engine start and go right to the take off run. Let these engines warm up before pouring the coals to it!

Let’s address this a bit further.

Most Lyc’s run smoother at the higher RPMs. I find they run smoother at 2600 RPM than 2400 RPM. Smoother is better! When an engine shakes through vibration, you are limiting the life of its components, as well as your radio’s, prop, and instruments. I have seen no difference (on average) of one Lyc making it further in life based on whether the pilot baby’s the rpm’s vs. the one’s who, like me, run them. Remember this: a pilot/owner who flies his plane at higher power settings, gets there faster, thus putting less time on the engine as well as the airframe.

1. An engine that runs faster, has less harmful carbon built up in it due to unburned fuel. Carbon is an enemy of our engines…So, run your engines.

2. Change the oil and filter regularly. If you don’t have a filter, have one added. It will pay for itself in engine life.

3. Add and subtract power smoothly and not ham-handedly,

4. Keep after external and internal rust,

5. Keep your temps under control

6. Use cowl flaps on ALL climb-outs,

7. For 201 and 231 owners, adjust your cowl flaps so that they trail open even when closed in the summer, about an inch. When you see temps nearing redline, forget the buffer in the gauge….do something to cool it.

8. Lean 50 degrees rich of peak

Those who attempt to squeeze every drop of fuel savings due to leaning is false economy. Run all your Mooney’s at least 50 degrees of peak on the rich side, unless you have Gami’s, and even then don’t be too conservative.

9. Another important area of attention is to keep your engine clean

Oil and grease buildup, chipping cylinder paint, poor fitting or old worn baffle seals, etc. will all subtract from achievable engine time. Heat is your mortal enemy! Do not allow excess heat to be retained by virtue of a dirty engine.

10. Balance your prop

One of the most cost effective benefits to any engine and other components, is a properly dynamic balanced prop by someone who really knows his stuff–and cares about the results. Write this down: You want to achieve 0.07 inches per second or below when balancing. I have owned in the past, a balance machine, and that was my goal. I was only unable to achieve that once, but your mechanic must stay with it long enough and not give up in attempting to achieve that figure. It can be done. You wouldn’t believe the lowering of pilot fatigue this makes from an engine that really needs a balance. Then you must re-do the balance every time a cylinder is removed or re-worked, prop overhauled, or otherwise each 2-300 hours as the engine wears in.

There is so much to properly operating engines in the hostile environment we face each flight, but a little research and effort will yield many more hours of safe engine operation. This adds to the satisfaction of owning and operating an aircraft.

I always hate to see the many owners having to sell their Mooney’s just because they had to have their engines overhauled early and couldn’t afford to leave that investment sitting in their airplane. It is a sad thing to watch loving Mooney owners cry after they see their baby’s fly away to some new home, but it happens a lot.

Squeeze as much life out of those over priced engines as you can and still be safe. It only takes a little more effort on your part, and not a lot of money.

In addition to becoming good, safe, competent pilots, we must also become good “power managers”. Especially, but not exclusively you high powered turbo guys.

Maybe at some point in the near future, we can address how to get an engine properly overhauled for less money, for those of us who simply cannot afford a factory remanufactured one…or a new one!

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