2000 rpm, 25" MP, 155 MPH 7.5 GPH, Anything wrong with this picture?

[jetdriven]

Search for "Target EGT" on this forum. It is covered pretty well. Basically, use the "sea level full rich 29.92 59f EGT". Usually around 1250-1300, which is ~250 ROP. Climb while leaning to this value. At high density altitude lean to this value beofre brake release. Monitor CHT and run a little richer if over 360 in climb. Above 3-5K, you can run 50-100 degrees leaner in climb.

[scottfromiowa]

Scott,

I saw your post after I dropped mine. Clearly, I didn't get it...

Does the Cayman have an air cooled engine or air cooled is only for airplanes now?

Best regards,

-a-

It's air cooled and normally aspirated. A boxer...very similar to my IO360A1A. Fuel injected, but with 295HP vs. the 200 in the M20E. Mechanical precision and a beautiful "musical sound" from comes from behind you. Do NOT drive one...as driving my VWCC is just plain boring after the Cayman S.

[scottfromiowa]

It's air cooled and normally aspirated. A boxer...very similar to my IO360A1A. Fuel injected, but with 295HP vs. the 200 in the M20E. Mechanical precision and a beautiful "musical sound" from comes from behind you. Do NOT drive one...as driving my VWCC is just plain boring after the Cayman S.

I should clarify...It's NOT a VW engine...It has side supplemental-air intakes but has coolant and is therefore liquid cooled.

[MagicCarpet]

What a great bunch of folks.

Let's see:

1. The Lycoming Operators manual shows full throttle and 2700 RPM with no limit, and operations up to 6 or 7" "oversquare." Also, at or below 75% power, operation at Peak EGT is recommended. They built the engine."

2. "Sorry, Carter. I fly my O-360 ROP, but there's no need to climb your Mooney with reduced power." ... "Read your Owners Manual and the Lycoming book. . . ."

3. "I'm sorry but these two statements seem really ignorant to me. ..... "Now as for the first comment, that seems really out of place on our machines."

4. "Quote of the day top honors..." "That builds camaraderie."

Wow, you guys are really special. What a great blog you guys have going here.

You can have it.

Cya.

[jetdriven]

Notice the personal attack but no logical reply to the points made. Sounds like the Beechtalk politics thread.

[MagicCarpet]

Sorry Byron, any logical reply would be countered an infinite number of times with incessant argument until concession. I don't have the cycles. Later man, much later.

[jetdriven]

Sorry Byron, any logical reply would be countered an infinite number of times with incessant argument until concession. I don't have the cycles. Later man, much later.

For the record, you were the one who came on here all judgmental and stating that your instructor in 1980 and your POH published in 1967 are rule of law, and everyone who does otherwise is stupid. Well, we all have vastly more information that we had in 1980, and some people evolve and some people still think smoking cigarettes preserves your insides and radium water is healthy.

Open you eyes, man. If you ever come to Texas I will show you my plane and what all the fuss is about. Seeing is believing. Once the dots are connected, it all makes sense.

[aaronk25]

If magic carpet engine looked that good operating the way the POH said, imagine how good it would look taking the consideration of others who appear to have taken today's data and applied it to a newer more proficient method of engine operation.

201er and jet driven are spot on and my guess is is if everyone operated their engine in that manner the 2000 hour recommended over haul might be something like 3000 hours. A lot to learn on mooney space if you come here WANTING TO LEARN.

[DaV8or]

The basic problem is always that people don't want to recognize there are two legitimate ways of operating our engines. Many want to believe that there is only one true way and therefore get offended when someone points out the other way. They take it to be an attack on their decision making, or knowledge. ROP and LOP both have their place.

[Heloman]

a

[BigTex]

If you're struggling on deciding if you should fly ROP or LOP, just upgrade to a carburetored engine. ROP is pretty much the only option.

[gregwatts]

I was always taught that every Mooney owners' opinion is a statement of fact! I think it comes down to who's mechanic can beat up the other mechanics............just sayin'

[DaV8or]

I was always taught that every Mooney owners' opinion is a statement of fact! I think it comes down to who's mechanic can beat up the other mechanics............just sayin'

Well if that's the case, ROP wins hands down! I have yet to meet a mechanic that doesn't tell you that LOP will burn your valves and ruin your engine.

[jetdriven]

Very few mechanics are trained in the efficient operation of aircraft engines. Very few pilots think you need to rig the nose gear to .030" preload, torque spark plugs to 35 FTLB with antisieze, and check magneto timing every 50 hours either.

[DaV8or]

Very few mechanics are trained in the efficient operation of aircraft engines. Very few pilots think you need to rig the nose gear to .030" preload, torque spark plugs to 35 FTLB with antisieze, and check magneto timing every 50 hours either.

Just curious, have you ever personally met a mechanic that recommended, or even approved of LOP ops. I never have. The best I've ever come across was "I hear some people have good luck with that, but I wouldn't recommend it. It's too risky."

[jetdriven]

I have personally met Mike Busch, and he is not only a mechanic but a CFII etc, with 3500 hours on his engines. Again, I have met very few mechanics that were trained pilots, not amateur pilots, but professional ones. Further, if these mechanicsa admonish LOP so much, then why are there piles of cylinders in the corner of the shop and logbooks in every plane I bought for a dealer that said "800 SMOH, 100 since top overhaul" from the 1950s through today. LOP on flat engines is a new thing, but old school for radials.

I have logged data that shows cooler CHTs while LOP and higher efficiency. I have data that shows peak exhaust valve temperature occuring between 25-50 ROP. I have an airplane which gets 17.5 NMPG at 65% power and close to 20 at 50% power. I have Lycoming saying its OK to run peak EGT at 75% power and below with no regard, but somehow 15 degrees leaner is somehow frowned upon. The Cirrus SR22-GTS and the Continental TSIO-520BE in the Malibu is ONLY allowed to operate at LOP power settings and in fact has LOP cruise FF limits which may be approached only if the CHT is below a set value. I have never seen a single NTSB or FAA report listing LOP operation as a causal factor in any accident, incident, or inflight engine shutdown. The only argument besides "That'll burn your engine up" is that extra oxygen left over from the combustion process somehow "oxidizes" the valves and exhaust.

I believe that you can safely run LOP between 50% and 75% power:

IF you have logged the GAMI spread and do so every 50 hours,

IF you have done the GAMI hi-low induction leak test or pressurized the intake for leaks,

IF you have a multi-point engine monitor,

IF you have done an in-flight LOP mag check and it runs smoothly,

IF you never exceed 400 CHT, and

IF the engine runs smoothly LOP.

If any of these paramaters cannot be met, run ROP (which can be safer in this instance) and investigate.

For takeoff, climb, and cruise over 75%, you can only run ROP safely. Although if range is a factor, a LOP takeoff and complete flight from brake release to touchdown can be accomplished. Running out of fuel is pretty hazardous as airplanes are not very treeodynamic, cornodynamic, rockodynamic, dirtodynamic, or hydrodynamic. Thats pretty hard on engines too.

That's part of the reason I joined Beechtalk. There are quite a few pilots who have ran engines to TBO twice on the same cylinders and cases running LOP and quite a few run 90% power LOP. Thats a pretty powerful argument.

[201er]

Just curious, have you ever personally met a mechanic that recommended, or even approved of LOP ops. I never have. The best I've ever come across was "I hear some people have good luck with that, but I wouldn't recommend it. It's too risky."

I got mine to concede that LOP is not harmful IF the fuel injection were accurately balanced and IF the temperatures were cool enough but he wouldn't recommend it anyway. That's a major victory in my opinion because my GAMI spread is 0.0 and LOP keeps my CHTs below 350 a lot of the time

What demonstrates a fundamental misunderstanding further is that he thinks (and I think many mechs/pilots do) is that LOP runs the engine hotter. But this is simply untrue. Forget looking at graphs and talking theory, I can clearly see lower CHTs flying a little LOP compared to flying 100ROP! I think if LOP was the more fuel costly way to fly, you'd have a hard time convincing me to go ROP instead. Now it's not only about fuel savings but that it's simply a cooler (pun intended) way of running the engine

[garytex]

Scott from Iowa: Please note that speed was MPH, not Knots. It was a calculated true airspeed using a Garmin 396 E6B function based on IAS, temp, barometer and altitude. The plane has a boat full of SWTA mods and I think maybe is particularly straight. It runs 165-175 mph true 30 to 50df lop at 8.5-9 gallons all the time. Oddly enough, throwing more fuel at it makes almost no difference. The engine noise changes a little bit, and I pick up maybe 2 to 4 or 5 mph, thats it. It just smooth won't go much faster.

Carusoam: All those things you mentioned preyed on my mind. The progressive nature of the fuel burn event (the faster it burns, the more pressure it generates, the more pressure it generates the faster it burns) combined with the slow movement of the piston not "running away" from the burn event and generating space as rapidly to regress the burn worried me. Kind of akin to the reloader that doesn't change a powder speed or charge weight jumping from lighter to heavier bullets. Bad things happen. We can manipulate the burn speed some with low MP, and very rich and very lean mixtures, but I wonder if it is enough to be safe from detonation that far over square. I watched like a hawk for any CHT up, EGT down excursions that would indicate detonation, saw none at all.

Danb: We have the same plane, and my red arc is different than the one you cite. Mine is 2100 to 2300, and I am unfamiliar with any associate MP limitations. Perhaps I am missing something. Can you enlighten me?

I had a 20 min descent from altitude today and came down at 2000 rpm, and MP built slowly from 20" to 25". All seemed good. It was really quiet.

ANYONE ACTUALLY FLOWN LIKE THIS?

Thanks, Gary

[garytex]

Jetdriven, your "IF"s are the most compact and cogent list of precautions Ive seen. They cover the bases. Well done.

Gary

[fantom]

I believe that you can safely run LOP between 50% and 75% power:

IF you have logged the GAMI spread and do so every 50 hours,

IF you have done the GAMI hi-low induction leak test or pressurized the intake for leaks,

IF you have a multi-point engine monitor,

IF you have done an in-flight LOP mag check and it runs smoothly,

IF you never exceed 400 CHT, and

IF the engine runs smoothly LOP.

If any of these paramaters cannot be met, run ROP (which can be safer in this instance) and investigate.

For takeoff, climb, and cruise over 75%, you can only run ROP

Exactly, except doing a GAMI check every 50 hours, if all else is smooth, seems excessive. Is there more to that?

[DaV8or]

I believe that you can safely run LOP between 50% and 75% power:

IF you have logged the GAMI spread and do so every 50 hours,

Impossible to run this test. My FF indication is so irratic LOP that it's impossible. Why that is, nobody knows. It's a mystery.

IF you have done the GAMI hi-low induction leak test or pressurized the intake for leaks,

Where do I find a mechanic that understands this, or will even do this? I seriously don't have a load of time to tinker in the hangar. When I ask about possible induction leaks, they say there is no blue staining, so therfore I don't have a leak. Case closed.

IF you have a multi-point engine monitor,

I'm OK there.

IF you have done an in-flight LOP mag check and it runs smoothly,

Never bothered. It doesn't run smooth with both mags on.

IF you never exceed 400 CHT, and

Not a problem. The CHTs never go over 380 no matter what I do. Engine runs real cold.

IF the engine runs smoothly LOP.

Well... not so much these days.

If any of these paramaters cannot be met, run ROP (which can be safer in this instance) and investigate.

And this is why I'm giving up on LOP ops for the time being. Running ROP, she purrs like a kitten and I can enjoy my plane instead of racking my brain wondering what the hell is wrong with it. I'm really getting sick of it being in the shop all the time anyways, much less trying to chase down why it won't run LOP well. If there were a LOP shop out there where I could drop my plane off and say "fix it" I would consider paying to have it done. Like I said above, I have yet to meet a mechanic, or shop that says this is a good idea, much less understand the problems and help me get there. Every mechanic that has looked at my engine says it's in perfect health and runs just fine.

Anybody know a shop in California that is gung ho on LOP and ready to tackle my problem/s?

[garytex]

DaV8or.

I am recently having eratic fuel flow indications that are getting worse with time. JPI suggests that it might be spark plug wire leakage. They say download the trace and look for spikes. Also I understand that if there is a 90 elbow anywhere close it will bamboozle the ensor on a pump driven system (but not a gravity flow).

When I ask about possible induction leaks, they say there is no blue staining, so therfore I don't have a leak. Case closed.

That is dangerous bullshit. Induction leaks eat cylinders, especially if you are running ROP. Bitter experience speaking here. I will PM you my phone number. Call me this weekend. There are several ways to test for induction leaks. I've seen a couple of leks, and there was no blue staining.

Gary

[scottfromiowa]

Scott from Iowa: Please note that speed was MPH, not Knots. It was a calculated true airspeed using a Garmin 396 E6B function based on IAS, temp, barometer and altitude. The plane has a boat full of SWTA mods and I think maybe is particularly straight. It runs 165-175 mph true 30 to 50df lop at 8.5-9 gallons all the time. Oddly enough, throwing more fuel at it makes almost no difference. The engine noise changes a little bit, and I pick up maybe 2 to 4 or 5 mph, thats it. It just smooth won't go much faster.

Carusoam: All those things you mentioned preyed on my mind. The progressive nature of the fuel burn event (the faster it burns, the more pressure it generates, the more pressure it generates the faster it burns) combined with the slow movement of the piston not "running away" from the burn event and generating space as rapidly to regress the burn worried me. Kind of akin to the reloader that doesn't change a powder speed or charge weight jumping from lighter to heavier bullets. Bad things happen. We can manipulate the burn speed some with low MP, and very rich and very lean mixtures, but I wonder if it is enough to be safe from detonation that far over square. I watched like a hawk for any CHT up, EGT down excursions that would indicate detonation, saw none at all.

Danb: We have the same plane, and my red arc is different than the one you cite. Mine is 2100 to 2300, and I am unfamiliar with any associate MP limitations. Perhaps I am missing something. Can you enlighten me?

I had a 20 min descent from altitude today and came down at 2000 rpm, and MP built slowly from 20" to 25". All seemed good. It was really quiet.

ANYONE ACTUALLY FLOWN LIKE THIS?

Thanks, Gary

Of course Gary...as you stated...I had "knots" on my brain when I replied...

[DaV8or]

DaV8or.

I am recently having eratic fuel flow indications that are getting worse with time. JPI suggests that it might be spark plug wire leakage. They say download the trace and look for spikes. Also I understand that if there is a 90 elbow anywhere close it will bamboozle the ensor on a pump driven system (but not a gravity flow).

When I ask about possible induction leaks, they say there is no blue staining, so therfore I don't have a leak. Case closed.

That is dangerous bullshit. Induction leaks eat cylinders, especially if you are running ROP. Bitter experience speaking here. I will PM you my phone number. Call me this weekend. There are several ways to test for induction leaks. I've seen a couple of leks, and there was no blue staining.

Gary

Good tips. I was planning to send my engine logs to EI and see if they have any suggestions. It's easy to get the irratic fuel flows, so I'll go do a flight, make it screw up and send it in.

Intersting about the plug wires. In addition to the fuel flow issue, I also have an occational voltage spike that triggers my monitor to alert me to a problem with the electrical buss. Reviewing the data shows an instantaneous voltage spike. EI says it could be caused by radio broadcasts and there is some sort of termination they can do to solve it. Since they said that, it does seem like the alerts do come after I close the mic.

In addition, on the fateful flight to Red Bluff, the other symptom I had was a high pitched buzzing in my headset kind of like a knat in your ear. I mentioned this to the mechanics up there and this is what set them down the ignition path initially. Maybe I do have an issue with a wire somewhere. We never tested all the wires, just the ones to #2 cylinder.

I'll have to check on the 90 degree elbows. I don't remember any, but I can't recall that well.

As to the induction leaks, well, what can I say. Every mechanic I've asked has glazed over in that "Oh God, please don't make me do that" look then tell me everything is fine. See, they're the "experts" and I'm just the consumer and to this point, I've taken them at their word. I figure they must have some experience in the matter. I'm starting to really question how good most A & Ps are. I've had the same issues with auto mechanics and the worst is diesel truck mechanics. Problem is, I know enough and have worked on engines, cars and motorcycles since I was 8, my first mini bike project. I can tell BS and see the mistakes.

Airplanes are new to me though and they are different. I have been letting others use their judgement on the basis that they have training and experience that I don't, but that is starting to change... My trust is waning.

[jetdriven]

Exactly, except doing a GAMI check every 50 hours, if all else is smooth, seems excessive. Is there more to that?

Probably. It still id a good idea to check it every 50 hours, it only takes 15 minutes. Dirty injectors can cause problems. The principal risk is the cylinder you use to lean (i our case, #3) having a clogged injector. It will peak way sooner, and if you set it 15 LOP then the others are running 20 ROP and might cause trouble.