|
Two thoughts.
First, running "a little bit rich" of lean of peak is bad. An engine with matched injectors (like GAMI) can be run at the recommended LOP setting, which I think is 50 - 100 degrees on the lean side of peak. If you can't achieve this, perhaps because of roughness, then you should follow the POH, which says to run 50 - 100 degrees on the rich side of peak. Running at near peak is not recommended. This is part of this LOP mantra: do it only with matched injectors (for smooth running), do it only with an engine analyzer, do it only if you've read and can follow closely the LOP procedures, which includes being 50 - 100 degrees away from peak. (Another condition I normally add is that your engine not be under warranty, since running LOP might give the manufacturer/overhauler grounds for voiding the warranty.)
Second, on the issue of engine longevity, there are two camps. The theory and the empirical data shows convincingly that if you run LOP properly, the engine will last longer; the combustion is cleaner and the engine (especially the exhaust valves) run cooler. I subscribe to that -- with emphasis on doing it properly. Another camp, led by an ex-member who has considerable experience with Skymasters, is that LOP harms the engine, and he has seen examples of that. I believe such instances are the result of improper LOP operation, but that's only my opinion.
All of this has been rehashed in considerably more detail in the thread that I reference in the first message above, and in the technical papers referenced in that thread. I strongly urge anyone considering LOP to read all of that material.
Ernie
|