I am a
supporter of LOP operations under the right circumstances, but I stand by my views.
Let's look at Walter's points.
1. Balanced Injectors. Many (most?) engines -- even new ones -- don't have balanced injectors and don't operate smoothly at LOP without GAMI injectors. We are in agreement here, except that Walter seems to suggest that a conforming engine (new or overhauled) has to have balanced injectors and operate smoothly at LOP. In theory perhaps. In practice, forget it. You almost certainly will have to buy GAMIs.
2. Engine Monitor. Walter views these monitors as a) mandatory, but not to operate LOP, and b) more necessary for ROP operation. I'm baffled by the latter point, in part because I've never heard it before and because it seems to run counter to what airplane manufacturers have historically done (i.e., they tell you to run ROP and they don't equip their aircraft with an engine monitor). But on point a) every article I have read in support of LOP clearly indicates a need for an engine monitor. As an example, take the one in the July 2009 issue of AOPA Pilot magazine at
www.gami.com/articles/frugalflyer.php. Here is an excerpt:
Electronic engine monitors that show cylinder head and exhaust gas temperatures for every cylinder are necessary for safe LOP operations. Here's another:
GAMI showed that with precise fuel/air metering systems and graphical engine monitors high-compression and turbocharged piston aircraft engines could run safely and reliably LOP. In the article, engine overhaulers specifically point to LOP without engine monitors leading to engine damage. In the recent May 2011 issue of the same magazine, in the dogfight article on LOP vs. ROP, it's stated that those engine rebuilders who now accept LOP operation require both balanced injectors
and engine monitors.
3. Overhauled Engine Under Warranty. Walter believes that overhaulers should deliver engines with balanced injectors (my response in point 1) and should not object to LOP operation. I would like that too. But the reality is different: many (most?) engine overhaulers will not honor their warranty if you deviate from the POH, which for Skymasters means ROP operation.
So, at the risk of being repetitive, LOP is a good choice if you have "balanced" injectors (read: GAMI injectors), engine monitoring with cylinder-by-cylinder EGT/CHT readings, the willingness and ability to understand and manage the leaning process, and preferably an engine no longer under warranty from an overhauler which prohibits LOP.
Ernie