Quote:
Originally Posted by huddy
Just an FYI, for interest only:
Extensive research on aircraft engines has proven that for a normally-aspirated, fuel injected engine, running lean of peak does absolutely no damage to the engine, and results in running at peak power and efficiency. This is done with EGT measurements on each cylinder, not practical for most auto engines that don't have separate cylinder heads. The technique is to lean the hottest cylinder for 50 deg C lean of peak temperature. This works best when the engine has been equipped with balanced injectors. I would think for a water-jacketed engine it is less of a problem as temperatures would tend to be more evenly balanced. The technique does not translate well to carbureted engines, and is not recommended for turbocharged engines.
What the developers found is that a normally aspirated engine will quit from fuel starvation before it can get hot enough to cause damage.
See this article: http://www.gami.com/articles/frugalflyer.php (NOTE the article has a video that automatically opens, so you might want to mute your sound).
Be aware that there is still some controversy about this, between old timers and modern flyers, but I am unaware of any actual documented engine damage as a result of operating this way. For autos, YMMV. |
As mentioned, this is only good for injected engines with proper injectors and monitoring. Good individual cylinder exhaust temp monitoring has only fairly recently been made available.
And, yes, there is still controversy about this among pilots. Habits are hard to change.
Planes with nothing more than a carburetor [ or factory injectors] and tach [ or single exhaust temp probe/gauge] are still leaned the old fashioned way, just rich of peak.