Oil Consumption 2.5 qts in 1 hour! IO-360 A1A

[Shadrach]

22 minutes ago, Hank said:

Note that this Service Bulletin in for naturally aspirated, carbureted engines, which is not what you have in your F.

But it should be fine in my C, although I try to keep it to 70% or less myself.

Missed that, thanks!  You have to love our old POHs... clearly says full rich above 75% then shows fuel flow of 9.6 at 75.9%.

[Grandmas Flying Couch]

Do you guys think the old Marvel Mystery oil trick could have freed the stuck rings, saved the cylinder from being pulled?  

[jetdriven]

maybe the same technique but with Berrymans B12 chemtool.

[cliffy]

Nope on the MMO

The cylinder needs an IRAN including valves and guides You might need a piston Won't know until its cleaned and measured.

No big deal. Happens all the time to lots of folks. AMB- check the cam and lifters that you can see through the cylinder hole. 

Put it back on and go fly with straight mineral oil until the oil consumption goes back to normal. Read Lycoming's break in procedure. Its good for one cylinder or four. 

[EricJ]

2 hours ago, Hank said:

Note that this Service Bulletin in for naturally aspirated, carbureted engines, which is not what you have in your F.

But it should be fine in my C, although I try to keep it to 70% or less myself.

 

Lycoming SI-1094D is for all Textron Lycoming Opposed Series Engines.    There are sections for Normally Aspirated, Turbocharged, and Supercharged engines.   The only mention of peak EGT is in this paragraph:

The exhaust gas temperature (EGT) offers little improvement in leaning the float-type carburetor over the procedures outlined above because of imperfect mixture distribution. However, if the EGT probe is installed, lean the mixture to 100°F. on the rich side of peak EGT for best power operation. For best economy cruise, operate at peak EGT. If roughness is encountered, enrich the mixture slightly for smooth engine operation.
  

[cliffy]

The above works great UNLESS you are at an airport that has a high density altitude. 

[PT20J]

22 hours ago, Shadrach said:

On 4/3/2019 at 11:24 PM, PT20J said:

Help me understand some things, because I’m confused. 

I know what heat is, and I know what mass is, but what is heat mass and how does ICP affect it?

If I fly a M20J at 3000’ density altitude at 75% BHP and 50F ROP with CHT of 360F, exactly what damage would you expect that would shorten cylinder life and how do you know that?

 

I think Brad is suggesting that high heat and high pressure are a bad combination. His numbers are pretty conservative. Your numbers are not very conservative (75%@50ROP). In fact, that power setting is outside the factory recommendations for my airplane. I think your point is that the engine is under no eminent threat at that power setting. Inducing detonation in an NA injected Lycoming is nearly impossible at any setting. Nevertheless, some of them still need cylinder work at mid time. I don’t have any data to suggest that power settings have any bearing on mid time cylinder work, but I’d not begrudge someone setting conservative parameters. The thing is, those parameters keep shifting. 400 used to be the get your attention CHT then it was 380. if 380 is good, why not set the alarm for 370 if 370 is good why not...rinse and repeat enough times and people keep revising there parameters down to the point that they’re ultra conservative and proclaim anything outside their comfort zone as abusive. I am thrilled with the engine monitor tech we have today but it can get extreme. Folks managed to run engines to TBO long before we had decent monitors but you wouldn’t think that possible the way we talk today.

I think you hit the nail on the head. Sometimes I feel like the red box is the new shock cooling. My point in choosing  75% at 50F ROP and 360F (which is within Lycoming's allowable operating range, though just barely) is that this is often described as "the worst possible" operating point because the peak pressure will be at its highest there. But is that really bad if it is well within the design constraints of the engine? We don't have the engineering data, so we don't know. We do  know that it isn't going to detonate - APS has data for that.  And, we can reasonably assume that it isn't going to do any bottom end damage given that bottom end problems (except for camshafts) are rare. So, the question is: what's the extra pressure going to do to cylinders if the CHT doesn't get too high? It doesn't help me understand if someone says it "cooks" them, or you'll "shorten" their life, or it will cause "damage". This just means that the author doesn't really know and is just repeating something they heard or read - like the OWT about lean mixtures frying valves that went on for so long. It would be really interesting if someone could show that the rings blow apart or the valve heads break off from an extra 100 psi of peak pressure, but I haven't seen that.

I think these engines have proven to be amazingly strong and reliable. That is not to say that they won't last longer with more conservative operation, but I think obsessing over red boxes (which John Deakin himself has said is more of a concept than exact numbers) misses the point. I do think there is ample evidence that to get maximum service life, the engines should be operated frequently and the CHTs should be kept below 400F. Since I have no way to measure peak pressure, and I wouldn't know the design range for it even if I could, I don't lose sleep over it.

Skip

[Shadrach]

5 minutes ago, PT20J said:

I think you hit the nail on the head. Sometimes I feel like the red box is the new shock cooling. My point in choosing  75% at 50F ROP and 360F (which is within Lycoming's allowable operating range, though just barely) is that this is often described as "the worst possible" operating point because the peak pressure will be at its highest there. But is that really bad if it is well within the design constraints of the engine? We don't have the engineering data, so we don't know. We do  know that it isn't going to detonate - APS has data for that.  And, we can reasonably assume that it isn't going to do any bottom end damage given that bottom end problems (except for camshafts) are rare. So, the question is: what's the extra pressure going to do to cylinders if the CHT doesn't get too high? It doesn't help me understand if someone says it "cooks" them, or you'll "shorten" their life, or it will cause "damage". This just means that the author doesn't really know and is just repeating something they heard or read - like the OWT about lean mixtures frying valves that went on for so long. It would be really interesting if someone could show that the rings blow apart or the valve heads break off from an extra 100 psi of peak pressure, but I haven't seen that.

I think these engines have proven to be amazingly strong and reliable. That is not to say that they won't last longer with more conservative operation, but I think obsessing over red boxes (which John Deakin himself has said is more of a concept than exact numbers) misses the point. I do think there is ample evidence that to get maximum service life, the engines should be operated frequently and the CHTs should be kept below 400F. Since I have no way to measure peak pressure, and I wouldn't know the design range for it even if I could, I don't lose sleep over it.

Skip

Agree with all of the above. The thing is that sometime in the early 2000s, a highly respected pilot/mechanic/dentist was making the rounds on all of the boards and email lists telling everyone that 50 ROP was the worst place to run an engine. He made very compelling arguments and offered more detailed information if folks were willing to take his class in Ada, OK. APS classes not withstanding, Walt made a big mark on the community that’s still visible.  As to the fuzzy red box, I have thought for years that it’s fairly narrow regarding the injected, angle valve Lycoming engines.

[ArtVandelay]

This probably won’t be a popular comment...
The red box and the other concepts that are taught by Advanced Pilot seminars are taught by
John Deakin: a 747 captain
George Braly: a practicing lawyer
Walter Atkinson: a dentist

Not a one has any engine development experience, only George has an aeronautical engineering degree ( a curriculum that has only 1 class on propulsion systems and teaches about turbines and rockets, not piston combustion engines).
I would want to go to a class taught by engineers who have developed combustion engines.
I would not take what they “teach” as gospel. Maybe better than what you would learn in an AP/IA school, and then again maybe not.


Tom

[cliffy]

How many Cherokee 180s are there out there that have been used since the 60s in flight schools? Beaten up, thrashed to death by new students? If the engines were so "delicate" that they would not make TBO or they would come apart without an expensive monitor (we never had them back then) does anyone think that the airplane and engine would have lasted so long? I'll include the 200 HP Lycs also. 

If they are so "delicate" why doesn't Lycoming mandate monitor use ? Thousands and thousands have been used with only a mixture control and "maybe" an EGT. 

Long periods of inactivity have more to do with longevity, on ANY engine, than any other factor. Why is it that Lycoming gives a better warranty for using up the hours in short order than if it takes you 7 or 8 years to fly off the TBO time? 

Now, maybe if you want to talk big 6 cylinders and high blowers I might be inclined to see the "necessity" of a monitor there. But, I've operated them to TBO with only 1 TIT gauge with very little engine maintenance.

Can we learn a lot more about our engines with the monitor? Sure. But is it absolutely necessary for the health of the engine? Nope! Both the airplane manufacturer and the engine manufacturer certify the airplane and engine with only those gauges installed at delivery, to go to TBO. 

Going to TBO doesn't necessarily mean "without engine work" between zero hrs and TBO hrs. But there are many that do.

[Grandmas Flying Couch]

I think keep cht below 400F, lean below 75% power and call it a day.  If I say a bridge is good for 10 tons, people will say running 10 ton trucks across it is the worst possible way to use it, so use 8 ton trucks.  However the bridge is probably good to 16 tons with a safety factor.  The red box might be peak pressures, great, need pressure to push the piston down and the engine was designed to handle these pressures with a safety margin.  You can operate your car at 45 mph to save the engine and transmission.  I say 50 degrees LOP at at 22 inches and 2600 rpm is way worse than 19 squared.  But what fun is that?  I'm going to 100 deg rop unless I need range, then I'm going up high 7k plus and rich of rough.  I dont think I caused this at all.  Thanks for all the input, operate your engine as you will, I think the red box is the worst possible place to operate WITHIN the design limits.  I will be going with a monitor just so I can get a heads up if stuff is crapping out in flight next time.  Give me an extra 15 minutes notice to a dying cylinder, yes please.  Or let me know a clogged injector is heating a cylinder on takeoff?  Also yes.  

[gsxrpilot]

4 hours ago, ArtVandelay said:

This probably won’t be a popular comment...
The red box and the other concepts that are taught by Advanced Pilot seminars are taught by
John Deakin: a 747 captain
George Braly: a practicing lawyer
Walter Atkinson: a dentist

Not a one has any engine development experience, only George has an aeronautical engineering degree ( a curriculum that has only 1 class on propulsion systems and teaches about turbines and rockets, not piston combustion engines).
I would want to go to a class taught by engineers who have developed combustion engines.
I would not take what they “teach” as gospel. Maybe better than what you would learn in an AP/IA school, and then again maybe not.

As someone who has taken the class in Ada, OK, I'd say you can be forgiven for not knowing anything about what you speak.

[Shadrach]

15 hours ago, ArtVandelay said:

John Deakin: a 747 captain, with 14 certified aircraft type ratings and authorization for the following experimental aircraft:  B-29 EC-121 FA-C123 G-F6F G-F8F(VFR ONLY) H-HURC MI-A6M N-P51 N-T28(VFR ONLY) SPITFIR.

George Braly: a practicing lawyer and aeronautical engineer. He is the chief engineer and founder of GAMI. He also served or serves as chief engineer at Tornado Alley turbos. He has been instrumental in developing multiple modifications and turbo normalizing applications for many aircraft.

Walter Atkinson: a dentist and an ATP and an A&P mechanic.

 

Your comment may be one of the most ignorant staments I’ve seen here in a long time. I fixed up the credential section a bit for you. Total and complete jackassery...

Edited April 8, 2019 by Shadrach

[carusoam]

Adentist, a lawyer, and a commercial pilot.... Even if these three fine gents had no background in aviation...

Their work in their lab with instrumented modern aircraft engines is impressive...

Their shared data is astounding...

 

For anyone that says a single EGT, and a single CHT is how the pioneers wanted to fly... they also flew with wooden props and rag wings.

 

Something happens while we are flying....   We have two options...

• Assess what is happening in real time... an engine monitor is a major requirement.
• Talk to the mechanic after we land...

It would be goofy to land straight ahead because of a single cylinder problem... (most often, generally speaking, PIC has to decide)

It would be worse to not land straight ahead if the engine is failing.... (impossible turns are best completed using an AOAi, and your best airmanship)

When everything is working as expected, a NA engine is pretty well isolated from self destructive tendencies...

 

Engine monitors have a tendency to let us know we have challenges before they become problems...

There are recent posts by MSers with...

• Semi blocked fuel injector
• dismantled spark plug tip
• loose plug wire (today)
• Lmag vs. Rmag timing
• failed mag
• failed oil ring

Some things are pretty obvious to some owners with lots of experience...

Some things are really obvious to some owners with an engine monitor...

Some things make themselves known to an owner with an engine monitor....

 

How do you like to approach the mechanic?

A) I think I have a plug problem

-or-

B ) Something is wrong with the top plug of cylinder #2...

 

Do I really need to run a compression check on all four cylinders before I know what cylinder needs to be looked at?  There is enough work that needs to be done... Best to start with what you know and move forwards....

 

Let’s say... You are pretty comfortable that the OEMs are avoiding high power, redbox, operations... at least when everything is running as expected...

Would....

• A shift in mag timing

-or-

• a semi blocked fuel injector

... cause a normal engine to operate in dangerous method?

 

If you got a load of Jet fuel that went undetected.... would something give a hint on the JPI sooner than standard instruments...

 

When you fly for a couple of years you will experience some or all of these minor events... look forward to the day you can install an engine monitor... just to better know that your engine is working as expected on every flight...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Marauder]

I stayed in a Holiday Inn Express last night. I can do anything.


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