Mike
"I can't disagree with Braly and Co. reference leaning a carbureted engine to LOP IF it is set up with EGT's very even. I've never met one, and frankly, I'm not going to pay a mechanic (or annoy a mechanic, as Steve points out) for hours and hours of chasing that very elusive goal. Even with that, you will NEVER approach the even-ness of an injected engines EGT's"
Both of mine do it very well and I had to do very little and it was hardly elusive. Tighten a hose clamp here and there and change. a bad plug that could'nt pass the LOP mag check. That's it, no big deal . Again, I'm paraphrasing alittle, Every conforming internal cumbustion gasoline engine can be run lean of peak, Everyone! APS say anything less than 70 degree EGT differentials is fine for smooth LOP ops, mine are often less than 40 and occasionally in the 20 to 30 range. You'd think it was injected and there dozen's of us or more on the CPA website who are doing it daily. Works like a champ.
"My point was and is, that the way most carbureted engines are set up, and the way most pilots operate them, LOP ops just aren't in the cards"
Not true, See the above. Tell you what Mike I'll pay for an annual membership for you to join the Cessna Pilot Association website if you'll take the time to do a couple of searches and read the threads by Walter and George on LOP ops.I'm going to warn you though you can spend a couple of hours a night for weeks catching up. But for anyone willing to do that they lay out for you, for free! .I've learned alot from you here and in your articles in the last couple of years, more than you'll ever know, but from what I see you only have half the picture about LOP ops..And it's the bad half!
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"John B. also brings up a very salient point: As the engine goes LOP, power is reduced. So, you increase power to regain some of what's lost, which increases fuel flows. Running LOP does reduce fuel flows for a given speed, but not by as much as most folks would have you believe."
If done properly you lose about 2% of your cruise speed, about 3 or 4 knots with the planes we're flying, and save 2 to 2.5 gallons per hour. Again, properly is important. Most newbies lean more than nessecary and lose to much speed.Let's just say for giggles that you save 2 GPH for 2/3 of a 2,000 TBO. Over 2600 gallons saved over the life of the engine. Seems substantial to me..
"The Ada guys (thanks for the reminder) are approaching cult status, to the point where nothing anyone else says is valid".
Mike ove the last year I've seen everything you, Alex and John haves said again and again on the CPA website and the APS guys have patiently refuted everything with hard data, all free for anyone willing to read a little. Their take on it as I see it is, LOP is it's just another tool that you can utilize when you need it, if you don't need it then run ROP if it suits your mission.
"Again, read the Lycoming bulletins. They specifically state not to run their engines LOP, again, with certain very specific model number exceptions. See the Lycoming flyer: "The New Old Leaning Technique" for Lycomings view on LOP ops in THEIR engines. "
I've read it, a couple of times actually and as George and Walter have pointed out, it had to pass through the LEGAL department.before public consumption., CYA.
"Now, I specifically asked a Lycoming rep if running one of their engines which was under warranty LOP would void the warranty, and his response was "no".
Continental, on the other hand, permits LOP operations on virtually all their injected engines, and recommends it on some."
That's right. Again, if it works on one engine it'll work on the others. The Physics are everywhere the same.
"I'm not agin LOP operations, but they have to be done very carefully, the engine HAS TO BE MONITORED VERY CAREFULLY by the pilot at all times, because a slight change in temperature or altitude can change the picture pretty fast, and as noted, if carbureted, the engine has to be really tweaked to make it work at all. Finally, you must use a multi probe EGT nad CHT gauge, and I don't mean one that can be cycled manually. You need a graphic analyzer.'
Not really, atleast according to the APS guys. If your LOP and the engine goes leaner then it gets cooler not hotter like it does when ROP. Cooler is safer. Actually LOP ops is less critical and easier on the engine than ROP if done properly. . Managing slight changes in altitude is is nothing more difficult than what you would do ROP, a little turn on the mixture in the proper direction, DONE. And as Walter and George have pointed out time and again you DON"T really need a multi probe montor to run LOP, to the contrary their postion is you should really have one if you don't , for trouble shooting and staying out of the " Red Box" when running ROP, were most of the damage is done.
"I've got an O=360 that runs 140 to 150 between cylinders on EGT. I've been trying to get a mechanic to improve that for several years now, but I'm not willing to tear down a good running engine for that purpose"
I wouldn't either. you just have a nonconforming engine. You can fix it but it'll take time, maybe alot of time or just live with it and run ROP. OTOH, Have you tried running partial carb heat once your in cruise and clean air. Alot of times that helps atomize the fuel better and bring the differentials down. Alot of the (0470) crowd finds that if they keep the carb air temp somewhere around 50 F their differentials come right inline and they can run LOP smoothly.That and of course chasing down any induction leaks, which can be extrenely difficult and often counter-intuitive..
WSH
