ROP vs LOP

[Marauder]

5 minutes ago, Shadrach said:

This place is a collection of unsavory characters with questionable judgement!

But you left out the most important attribute -- good taste in women!

[Marauder]

Just now, N6758N said:

That sums it up pretty accurately. It is a shame to argue on here about differences of opinion, I think 90% of us would get along great if we meet in person. I am willing to admit my knowledge of combustion science is limited to textbook basics. We are all free to do what we like with our airplanes, my point was that with the wealth of information on the internet, some may be tempted to follow something blindly while ignoring other facts being presented to them. 

You and Ross should both show up to one of Stinky Pant's fly-ins to discuss the finer details of LOP over a cheap airport cheeseburger.

[N6758N]

Just now, Marauder said:

You and Ross should both show up to one of Stinky Pant's fly-ins to discuss the finer details of LOP over a cheap airport cheeseburger.

I would enjoy that! I emailed Mike a while back to add me to the NJ Mooney list, but I'm not sure if it went through.

[Shadrach]

4 minutes ago, N6758N said:

That sums it up pretty accurately. It is a shame to argue on here about differences of opinion, I think 90% of us would get along great if we meet in person. I am willing to admit my knowledge of combustion science is limited to textbook basics. We are all free to do what we like with our airplanes, my point was that with the wealth of information on the internet, some may be tempted to follow something blindly while ignoring other facts being presented to them. 

Agreed. The problem is I don't recall you referencing any facts.  Show me the facts on bottom end failure and I'm happy to consider the information.

If you besmirch someone who's recommendations are largely data driven, expect some push back. 

[Marauder]

I would enjoy that! I emailed Mike a while back to add me to the NJ Mooney list, but I'm not sure if it went through.

Send a PM to Stinky Pants and he will do the setup.

 

[N6758N]

6 minutes ago, Shadrach said:

Agreed. The problem is I don't recall you referencing any facts.  Show me the facts on bottom end failure and I'm happy to consider the information.

If you besmirch someone who's recommendations are largely data driven, expect some push back. 

I agree, and I don't have facts to backup the bottom end argument. My point was that you can't follow everything you read on the internet and always expect the same result. 

[Shadrach]

9 minutes ago, N6758N said:

I would enjoy that! I emailed Mike a while back to add me to the NJ Mooney list, but I'm not sure if it went through.

The NJ boys are a tough crowd...very opinionated! if you find yourself around HGR let me know, I'll buy lunch!

[mccdeuce]

Out of curiosity - I generally am running ROP right now. I want to fly her LOP but am seeing some roughness and a fuel smell whenever I attempt it. 

Have GAMIs and electronic ignition. (Had same rough/fuel with 2 mags too). 

Last spread test was within .5gph will try another test soon. The fuel smell makes me more nervous than the roughness. 

[bonal]

8 hours ago, gsxrpilot said:

With all respect...

Science is in the business of debunking theories and beliefs that have been held in error for eons. I completely agree with your point about Busch. But the guys at GAMI are in a different category. They are scientists who test, measure, and either confirm or debunk long standing theories based on real data.

Mariners who had spent their entire lives at sea were absolutely sure the earth was flat until science proved them wrong. It's interesting to me that over on the Beechtalk forums, anyone disputing that LOP operations isn't settled science, is considered in the same boat as the flat-earth folks.

Doing what is most comfortable for you is just that, comfortable for you, and no more. It has nothing to do with the health or harm to your engine.  There's nothing wrong with doing what's comfortable, it just can't be equated to engine health. 

JUST HOLD ON A MIN WHAT DO YOU MEAN THE EARTH ISNT FLAT!

[aviatoreb]

Just now, bonal said:

JUST HOLD ON A MIN WHAT DO YOU MEAN THE EARTH ISNT FLAT!

It is locally flat since it is a topological manifold, however globally it is not the trivial manifold.

[bonal]

8 hours ago, cnoe said:

With all due respect, in the absence of an engine monitor that displays the EGT of EACH INDIVIDUAL CYLINDER you have no idea whether you are running LOP or not. Sure, your factory gauge might show an EGT drop, but the other 3-5 cylinders may all be running 50 ROP. More likely you may be running one cylinder at 20 LOP, another at peak, another at 20 ROP, and the fourth at 50 ROP. There's simply no way to know without a good monitor. I suspect that this is the exact reason why LOP operations gets such a bad rap by many old-school mechanics; the pilot THINKS he's LOP while in fact he's got one (or more) cylinders that are still in the red box.

As mentioned before you've got no worries at high altitudes or low power settings (65% or less), simply lean for best power or best economy and be done with it.

 

 

Agreed just doing the best I can with what I have so maybe I'm rich or lean which is why I stated my procedure is to lean to rough then rich back to smooth. and really even if you have al the bells and whistles isnt that what we all do to some extent.

[aviatoreb]

2 hours ago, Marauder said:

You and Ross should both show up to one of Stinky Pant's fly-ins to discuss the finer details of LOP over a cheap airport cheeseburger.

n10933 is at the paint shop....so next time you see her she will have new colors and design and new tail number...and already new interior...but i have not seen a fly in mentioned for a long time.  but hey deleware guys...fly in at/to a crab shack please.

[bonal]

Just now, aviatoreb said:

It is locally flat since it is a topological manifold, however globally it is not the trivial manifold.

It's only round to those that fly in the flight levels with turbo's

[Marauder]

n10933 is at the paint shop....so next time you see her she will have new colors and design and new tail number...and already new interior...but i have not seen a fly in mentioned for a long time.  but hey deleware guys...fly in at/to a crab shack please.

Almost forgot about that promise. When were you supposed to be in the area?


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[aviatoreb]

date keeps slipping....lets say if not by sept, then i would come especially for it.   but i have a service stop to make at klns in july.... and likely a trip to princeton in july....but i want a crab shack!  i grew up on crabs and have not had crabs for a few years.  old bay spice...mmmm!

i do have two separate business trips to dc to do in june but they need to mid week and quick turns...so no good to meet anyone - and a complicating factor for aviation socializing - when i am in dc - any free time i find - my mom owns me!  she is there.  :-)

[aviatoreb]

4 hours ago, Shadrach said:

Combustion science couldn't give two shits what you are comfortable with. I am pretty sure that Mr. Busch is in the same camp. You seem to be long on opinions and short on understanding. My recommendation to you is that you read up bit on subjects before commenting on them. Reading Mr. Busch's CV would be a good start. Indeed he may be more of a pilot than mechanic, but then he's more mechanic than most mechanics.  

Why don't you post your CV so we can see how you stack up?

Wow! i like mike busch even more than before after reading his cv... he did an undergrad in math at dartmouth, and it said he at leasted started graduate studies in math at princeton...i presume he didn't graduate from princeton since no degree is listed...and its true these phd programs are pressure cookers with a high attrition rate... but that doesnt stop me one bit from respecting him more one bit...since still we are judging him as an original thinker a&p engineer type...and clearly better than most in this field...he is a clear, original and logical thinker.  kudos mike bush!

[Marauder]

date keeps slipping....lets say if not by sept, then i would come especially for it.   but i have a service stop to make at klns in july.... and likely a trip to princeton in july....but i want a crab shack!  i grew up on crabs and have not had crabs for a few years.  old bay spice...mmmm!
i do have two separate business trips to dc to do in june but they need to mid week and quick turns...so no good to meet anyone - and a complicating factor for aviation socializing - when i am in dc - any free time i find - my mom owns me!  she is there.  :-)

Keep us posted!


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[gsengle]

Wow! i like mike busch even more than before after reading his cv... he did an undergrad in math at dartmouth, and it said he at leasted started graduate studies in math at princeton...i presume he didn't graduate from princeton since no degree is listed...and its true these phd programs are pressure cookers with a high attrition rate... but that doesnt stop me one bit from respecting him more one bit...since still we are judging him as an original thinker a&p engineer type...and clearly better than most in this field...he is a clear, original and logical thinker.  kudos mike bush!

No kidding, a fellow alum!


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[Shadrach]

2 hours ago, mccdeuce said:

Out of curiosity - I generally am running ROP right now. I want to fly her LOP but am seeing some roughness and a fuel smell whenever I attempt it. 

Have GAMIs and electronic ignition. (Had same rough/fuel with 2 mags too). 

Last spread test was within .5gph will try another test soon. The fuel smell makes me more nervous than the roughness. 

You wouldn't be running anything other than 100LL through it would you?

If not, I find the fuel smell puzzeling. At .5 spread, you should be able to run smooth to well leaner than you'd ever need to.

[Shadrach]

10 hours ago, cnoe said:

With all due respect, in the absence of an engine monitor that displays the EGT of EACH INDIVIDUAL CYLINDER you have no idea whether you are running LOP or not. Sure, your factory gauge might show an EGT drop, but the other 3-5 cylinders may all be running 50 ROP. More likely you may be running one cylinder at 20 LOP, another at peak, another at 20 ROP, and the fourth at 50 ROP. There's simply no way to know without a good monitor. I suspect that this is the exact reason why LOP operations gets such a bad rap by many old-school mechanics; the pilot THINKS he's LOP while in fact he's got one (or more) cylinders that are still in the red box.

As mentioned before you've got no worries at high altitudes or low power settings (65% or less), simply lean for best power or best economy and be done with it.

 

 

I personally would be perfectly comfortable leaning any well maintained, injected lycoming 4 cyl without a monitor. I'd look at installing one ASAP, but I am absolutely confident I could safely lean with indicated airspeed and engine roughness alone. 

[N6758N]

Just now, Shadrach said:

I personally would be perfectly comfortable leaning any well maintained, injected lycoming 4 cyl without a monitor. I'd look at installing one ASAP, but I am absolutely confident I could safely lean with indicated airspeed and engine roughness alone. 

Its true that is the way it was done long before engine monitors existed. I don't see any issue with this method either, but it would be interesting to see if you could see a difference in how many engines made it to TBO (and overall engine health) and beyond 50 years ago versus today, I would bet that there is little to no difference in that data, even with the implantation of engine monitors in a majority of the GA fleet. 

[Shadrach]

1 hour ago, N6758N said:

Its true that is the way it was done long before engine monitors existed. I don't see any issue with this method either, but it would be interesting to see if you could see a difference in how many engines made it to TBO (and overall engine health) and beyond 50 years ago versus today, I would bet that there is little to no difference in that data, even with the implantation of engine monitors in a majority of the GA fleet. 

I agree. My engine monitor is to ensure that I see something before it becomes catastrophic.  The "lean until rough and enrich" works on my bird, but it is not optimal as depending my engine will run smoothly to 80 LOP or more depending on MP.

[Shadrach]

1 hour ago, bluehighwayflyer said:

I have been running LOP with only digital fuel flow and four probe EGT instrumentation for 7 or 8 years now. Typically at 65 percent power and below but on occasion I have gone up to 75 percent power LOP.  I have a matching four probe digital CHT instrument on the shelf but so far I haven't really felt the need to install it. 

Oh.  I'm currently at 1900 hours SFRM and running strong. At least the last 500 have been LOP.  

Jim

I don't have FF displayed (though I did plan for it by adding a transducer when I replaced the fuel hoses).  I run LOP mostly at high power down low into the wind or on short hops to visit family around the state. I am perfectly happy running firewalled with the ram air open at 2500 rpm at 2500ft... in February!  I have spent a great deal of time in the vicinity of 80% power LOP (can't confirm exactly without FF displayed). My engine is very happy there, but it can be challengine to keep CHTs above 300df in the coldest months.  If winds are favorable, I am flying as high as I can and choosing my power setting based on what I need to do.  

[carusoam]

McD,

check your Fuel injector vent holes.  They are known to vent fuel.  If it is venting fuel there is probably a small blue trace around it.  It is supposed to be oriented in one direction or another.  The FI doesn't know it is running LOP.  It doesn't talk to anything.

 

Others,  

Depending on how well the fuel distribution is balanced amongst the cylinders....  The challenge with leaning until rough, then enrichen til smooth...  the roughness probably occurs somewhere after peak. Enrichening back til smooth may not bring it all the way back to peak.  Adding some amount like 50°F more richness can be Red Box territory below 8k'.

 

Instrumentation is spreading everywhere...  

Best regards,

-a-

Edited May 4, 2017 by carusoam

[Skates97]

7 hours ago, Marauder said:

But you left out the most important attribute -- good taste in women!

I think the jury may still be out on that one. Just when they are ready to declare a verdict it seems a new piece of evidence "weighs in" (pun intended) and then they must go back and deliberate more...