[kevin]

I am not a LOP fan, I always ran my engines 100 degrees rich of peak. There is some evidence from these recent discussions that that might not be the right thing, but I want to ignore that for the moment.

For me, the purchase of an engine analyzer was never tied to running LOP. I wanted an analyzer to allow me to monitor and troubleshoot the engine. I had the inexpensive EI guage that provides the EGT for each cylinder on both engines, the CHT on one cylinder on each engine, and the TIT on each engine, all in one 2 1/2 inch hole.

I wanted this guage primarily to help me avoid inadvertantly harming the engine, without knowing it. This could happen with a clogged injector for example, which could raise the EGT in the cylinder to peak, and running it there for hour after hour would very likely be harmful. With the analyzer, I would know immediately if it happened, because the gauge would alarm. I didn't have to watch the gauge much, just set the alarms and let it watch the engine for me, alerting me to out of range values.

Even when it would not have harmed the engine, if I got a fouled plug or something, it was nice to be able to know what cylinder the problem was in, before I even shut down. Yes, there are other ways to troubleshoot, but they take a little more time.

So, my only point is that I think there is a lot of value to analyzers, especially the less expensive ones, just for doing a good job of monitoring your engine, easing maintenance, and sometimes preventing signifcant damage.

I think it is important to note that when our airplanes were manufactured, the monitoring technology was FAR more expensive than it is now. I believe Cessna does offer engine analyzers as an option on new piston 206's built today, just as they used to offer the single needle EGT gauges as an option when our birds were built, because back then the single needle indicator was the only reasonably affordable and practical option.

Last, and probably most importantly on a center line thrust airplane, the EI gauge would give me an immediate indication (via a red light on the gauge) which engine has failed if I lose one. Even if it was only a partial power loss, one operating parameter or another would be off, and would cause the alarm light for that engine to illuminate.

For the same reason, I used to have oil pressure sensors connected to an annunciator to warn me when oil pressure dropped in an engine. This would immediately alert me if I lost oil pressure (hopefully in cruise) so that I could shut the engine down and maybe save it. I know, we should all be scanning gauges fast enough to catch it, but the sensor would be an instant indication, and would alert me even if I got busy. But that is kind of off topic, sorry.

Kevin