anonymouse

New to me M20K - many questions (now AOG)

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As some may know, I recently purchased N231PG sourced from this board, and have flown it about 20 hours since then. I'm a reasonably experienced pilot, am comfortable flying LOP, hard IFR, etc. but this is my first Mooney, first turbo plane, and first with tip tanks. I've PM'ed a lot with @jlunseth and have read most of the "M20K engine settings" threads extensively. Several things about the plane, and the engine, continue to confound me. I'm at the stage where I'm safe, but there are several things that just don't make sense to me that I've assembled into one thread. Thanks in advance for your thoughts/assistance with several threads of questions.

I should say that I'm getting a fuel injector cleaning and fuel flow setup (particularly on the low side) tomorrow, which may clean some of the engine curiosities up. I have a GB engine, gami's, turbo plus intercooler, merlyn wastegate, and JPI engine monitoring/fuel flow with sensors < 12 months old, and the engine baffling, fuel intake and exhaust systems were all replaced 10 months ago. Based on my reading, I try to keep CHT's 380 or less, TIT's below 1600, and EGT's 1550 and below, and MP 36" and below. Within those guidelines, I feel "boxed into corners" LOP and ROP with this engine with very narrow acceptable engine setting windows, as described below.

Engine Curiosities

Takeoff - On takeoff, I shoot for 36", 2700, full rich, cowl flaps open, which gives me about 22 GPH and climb all the way using those settings. Cylinder 2 is my hottest on climb and I find myself lowering the nose to only 1-200 fpm after a few minutes to keep cylinder 2 below 380 CHT. The other 5 cylinders are all around 360 or so. EGT's are all around 1500 and TIT stays about 1560-1570. Eventually, I make it to altitude, but so far I haven't had occasion to go above 13,000.

1. Even at full rich all the way up, I can't seem to keep that one cylinder cool enough to get anywhere significantly high, even though the usual limiting factor seems to be TIT for others. Any guesses?

Cruise (LOP) - After a minute of leveling off/speeding up/cooling off, being one of the cool kids, I then go for the big mixture pull to go LOP. I don't linger about the move in any sense, but I've noticed that my TIT reading will go near/above 1700 during the (rapid) transition. By the time I've pulled back to about as lean as the engine will run smoothly, I'm at something like 33-34", 2500, 1550 TIT 11.5-11.7 GPH, flaps closed. Cylinder temperatures are cool as a cucumber - #3 is the hottest CHT at 350, #2 now is the coldest cylinder at 280, EGT's are in the 1400's.

1. LOP or absolute temperatures? I've read @jlunseth's epics on how you really have little to no idea of what 'peak' is b/c of the mechanism of the Merlyn's. I'm also confused whether I should be paying more attention to leaning off CHT/EGT as GAMI seems to suggest or TIT as the POH does. If I'm looking for, say, 50 LOP TIT, isn't that 1650? If I touched nothing else aside from mixture, I could in theory be 60 degrees LOP CHT, 120 degrees LOP EGT and 130 degrees TIT at 34-36". I'm flying as per settings in the other threads, but can't square the LOP temperatures against maximum power settings.

2. Why is cylinder #2 the hottest on climbout, but the coolest LOP? Vice versa for cylinder #3?

3. The engine is rated to deliver 100% power continuously, yet I've been admonished that 12 GPH LOP (which is 78% power) is in the "red fin/red box" and I shouldn't pull that much power LOP. If the temperatures at that setting are essentially the same as above, why is it any different/more harmful?

4. At the settings above, are the other 5 cylinders that are 280-320 CHT too lean/too cool?

5. On the ROP side, EGT's/CHT's are relatively even across cylinders. On the LOP side, the EGT difference between #2 and #3 blows out to 180 degrees. Why?

6. If I accept that my engine is barely able to run LOP in an acceptable power setting, how do I handle a climb say from 10,000 to 12,000, or a strong downdraft? Go back to full takeoff configuration/ROP?

Descent - I pull back to 20" MP, which zings me back to ROP and a low power setting. I have to richen things a few turns to get to peak TIT for descent, but everything seems to generally cool gradually and be happy.

Cruise (ROP) - "these engines are just too cattywompus/untuned/etc." you say - just fly ROP.

In my last flight, I was stepped down to 6000 and then had to cruise for 25-30 minutes at that elevation. Given that I've already put myself ROP from the descent above, in my mind, I'm basically flying a normally aspirated plane here. At full rich mixture, however, TIT increases pretty quickly at relatively low MP. Anything above, say, 25", results in a TIT getting near 1600 (at 2500 rpm if that matters). CHT's/EGT's are all 340-350/1400's. IIRC, I'm indicating about 12.5 gph.

1. Why does a setting of say, 29" MP result in an unacceptably high TIT, but 36" (takeoff) not? If I was in a normally aspirated plane, the engine would be able to pull 27" or so, so I'm barely asking the turbo to do anything.

2. Is "full rich" rich enough in this context?

3. What's the best way to keep the TIT cool in this situation? I don't have any more red knob to add, and feel like I should be able to get more power out of the engine ROP without making my turbo melt.

4. If I'm having this issue at 6000, would it be worse at higher altitudes with less dense air? If so, how the heck am I supposed to get up to said higher altitudes if LOP barely works and ROP is too hot TIT?

Oxygen System - I had occasion to use the onboard oxygen system last night for the first time - a night flight at 12k. I have two of the Oxysaver cannulas, plugged them in, and rotated the oxygen knob "on", and lo and behold oxygen came out.

1. How does one 'set a flow rate'? The ball in the little meter showed "20,000 elevation", but rotating the knob is almost a binary function - either the ball was at 20,000, or it immediately fell to 0.

2. I consumed about 1/3 of a tank in 2 hours with 2 passengers. Is that normal/acceptable?

430W annoyances

1. I'm using the calculator on my 430W's "AUX" page, and at the cruise settings highlighted above, I'm usually somewhere around 170 kt. TAS. I flew back and forth to PHX from SoCal last night, and head/tail winds were forecast to be about 30kt. Going East, GS was about 200 kt., as expected. Coming back West, GS was 120kt., rarely exceeding 130kt. If anything, the storm/winds were dying down. While it's possible the winds were simply stronger than forecast coming back, I've had the same phenomenon seemingly every flight heading West, where TAS - expected wind > GS. This, obviously, could just be psychological, but I don't remember having the same issues in my previous planes.

2. I've flown behind 430's almost since beginning of my flying career, but this one hasn't been updated in quite awhile and the firmware is old (v 2.3?). If I change a field, say, to display the VNAV or cross-track error on the main screen, it doesn't save from one power cycle to another. Is this a firmware issue, a battery backup issue, a configuration issue?

Fueling annoyances

I have a fuel totalizer and use it. Since you never really know how much the line guy put in, error will build over time. Trying to get a visual indication of how much gas is in the tanks is absolutely befuddling. I have tip tanks. The main tanks have those amazingly annoying anti-siphon valves. To make things even more strange, I'm not convinced that my tanks are symmetrically installed and/or the baffles are equal. For example, one main tank will be filled to the anti-siphon valve, yet (what I think) is an equivalent amount of gas in the other wing has the fuel level far below that, with more apparently having sloshed over to the tip tank. The cockpit fuel gauges will burn down to about 25 gallons indicated (on both sides) and remain there for a long time whilst burning off the fuel in the tip tanks, and then descend from there. I know that the answer here is to drain everything and put in a known amount of gas to have some totalizer certainty, but how do other owners do a visual fuel level check? How do you fill the tanks? What is full? What does a full main tank look like? If I (in theory) had empty mains and filled the tip tanks, how long does it take for the gas to drain down to the mains?

Edited by anonymouse

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*Members that donate $10 or more do not see advertisements*

So...

0) what are tip tanks in your Mooney? I haven’t seen these yet...

1) You know to use the big pull method based on your collected engine data... it minimizes the time in a very hot zone.... were you expecting to avoid the high TIT altogether? Are you quickly through this, or still getting used to the whole procedure. 

2) CHTs are a function of rate of heating vs rate of cooling... rate of heating is often indicated with EGTs and which cylinder runs leaner than the others... rate of cooling is often cylinder placement and how well the air flow is controlled with baffle seals.

3) Power ratings provided by book numbers and plane manufacturers have not always been appreciated by owners. The TC’d engine at high altitudes has the opportunity for some pretty hamfisted operators to operate.

4) some engines are set-up to be very un-cattywompus... seek out balanced fuel injectors for an answer...  compare your air intake geometry to modern IO550s on one end, and IO540s on the other...  curvy pipes and balanced fuel injectors matter.

5) Controlling TIT is the name of the game for engine exhaust parts longevity... FF and °F ROP is key to how cool things are running.  TIT is a solid piece of information in terms of things to avoid... full Rich may not always be the answer... 

6) CHTs also have some similar guidance... thin air at altitude makes cooling a challenge...

7) did you mention what inter cooler you are using or what pressure controller you have?

 

Why not break your ideas into separate topics... (like you have) and touch on some of them one at a time?

This looks like follow-up to transition training but no notes to go back over...

Answers are Very specific to your make and model with added equipment.  Some may not be very specific at all...

 

How attentive to your full list do you think anyone can be...?

you are not very familiar with the O2, fuel level system, and GPS system.... (from your list above) and asking all of these questions in one place should provide interesting results...

I may be missing something, but it seems like you may have taken on a lot of new stuff. Use caution, stay low, stay in good weather, use daylight, until this all gets to be a smooth operation...

If you feel rushing into getting this experience is a good idea...  @Houman shared a lot of his getting used to a Rocket at a high rate of speed...  the story is one part love of aviation, and one part tragedy.  

Concerned PP ideas only not a CFI...

Just Trying to say, help other people help you... so many deep questions all at once is going to miss a few deep answers...

Best regards,

-a-

 

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First things first, your takeoff FF needs to be turned up to at least 23.5, 24 is better. TIT on takeoff shouldn't be over 1400. This should be done before you fly the aircraft again.

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2 minutes ago, N231BN said:

First things first, your takeoff FF needs to be turned up to at least 23.5, 24 is better. TIT on takeoff shouldn't be over 1400. This should be done before you fly the aircraft again.

Yes, I think things are set up too lean - perhaps the last A&P used the factory engine parameters instead of the intercooler-based one.

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The problem most people run into is the mechanic still uses 40" for the set-up which leaves you lean at 36" or whatever you use with an intercooler.

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What N231BN said, your TIT in takeoff is too high, likely not being rich enough which wont help your CHT.  As for 2. Ill going to guess its your leanest cylinder, maybe too lean on takeoff getting you closer to peak, but likely still on the rich side, and then when you lean its going very lean, hence the lowest or lower cht.  You will find just a little bit of fuel makes a big difference, 10.5 to 11gph will change your temps and speeds a lot.

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9 hours ago, anonymouse said:

Oxygen System - I had occasion to use the onboard oxygen system last night for the first time - a night flight at 12k. I have two of the Oxysaver cannulas, plugged them in, and rotated the oxygen knob "on", and lo and behold oxygen came out.

1. How does one 'set a flow rate'? The ball in the little meter showed "20,000 elevation", but rotating the knob is almost a binary function - either the ball was at 20,000, or it immediately fell to 0.

2. I consumed about 1/3 of a tank in 2 hours with 2 passengers. Is that normal/acceptable?

Picking off these issues one at a time...

1. Flow rate is set by the ball. It can be precisely adjusted. But it is quite sensitive. Be gentle and adjust it for 12,000. You'll probably need to check it every so often as the adjustment will move and so will the ball. Or get a Mountain High O2D2 and let it handle the O2 distribution.

2. At a 20,000 flow rate, I'd say that's about right. But it also depends on the size of your tank. I have a 115 cu/ft tank in my 252 and above FL200 with the mask on, solo will get me about 8 hours of O2.

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The little ball in the O2 meter is a good place to start, but check and adjust with a pulse oximeter.

Check your POH for the chart about how much you ought to use (# of people and altitude).

If your POH doesn't have the chart, re-post and I will send you one.

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9 hours ago, anonymouse said:

As some may know, I recently purchased N231PG sourced from this board, and have flown it about 20 hours since then. I'm a reasonably experienced pilot, am comfortable flying LOP, hard IFR, etc. but this is my first Mooney, first turbo plane, and first with tip tanks. I've PM'ed a lot with @jlunseth and have read most of the "M20K engine settings" threads extensively. Several things about the plane, and the engine, continue to confound me. I'm at the stage where I'm safe, but there are several things that just don't make sense to me that I've assembled into one thread. Thanks in advance for your thoughts/assistance with several threads of questions.

I should say that I'm getting a fuel injector cleaning and fuel flow setup (particularly on the low side) tomorrow, which may clean some of the engine curiosities up. I have a GB engine, gami's, turbo plus intercooler, merlyn wastegate, and JPI engine monitoring/fuel flow with sensors < 12 months old, and the engine baffling, fuel intake and exhaust systems were all replaced 10 months ago. Based on my reading, I try to keep CHT's 380 or less, TIT's below 1600, and EGT's 1550 and below, and MP 36" and below. Within those guidelines, I feel "boxed into corners" LOP and ROP with this engine with very narrow acceptable engine setting windows, as described below.

I agree with others that your FF is too low on take off. So get that fixed first. Then run a GAMI lean test to see how wide the spread is and to understand which cylinder is leanest. This should explain quite a bit.

I never run LOP in my K 252, above 65% power. These engines are not known for making TBO and I'm trying to buck the trend. I'm over 1300 hours now and still going strong. But I believe part of that is going gentle on the engine. I'm always in takeoff power for climbs, Full, Full, Full. My ROP cruise setting is 75% power and my LOP cruise is 65% power. I ignore EGT values and only use them to determine peak. ROP cruise I often need a touch of cowl flap to keep the temps below 380 above 22,000 ft. LOP all cylinders are usually below 360 at the same altitude. In take off or full power full rich, my temps never exceed 360 at anytime on any cylinder. 

The disclaimer here is that I fly a 252 with the MB engine.

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9 hours ago, anonymouse said:

Fueling annoyances

I have a fuel totalizer and use it. Since you never really know how much the line guy put in, error will build over time. Trying to get a visual indication of how much gas is in the tanks is absolutely befuddling. I have tip tanks. The main tanks have those amazingly annoying anti-siphon valves. To make things even more strange, I'm not convinced that my tanks are symmetrically installed and/or the baffles are equal. For example, one main tank will be filled to the anti-siphon valve, yet (what I think) is an equivalent amount of gas in the other wing has the fuel level far below that, with more apparently having sloshed over to the tip tank. The cockpit fuel gauges will burn down to about 25 gallons indicated (on both sides) and remain there for a long time whilst burning off the fuel in the tip tanks, and then descend from there. I know that the answer here is to drain everything and put in a known amount of gas to have some totalizer certainty, but how do other owners do a visual fuel level check? How do you fill the tanks? What is full? What does a full main tank look like? If I (in theory) had empty mains and filled the tip tanks, how long does it take for the gas to drain down to the mains?

Yes, those anti-siphon valves are very annoying. I'd recommend starting at empty and either creating a dip stick or you might be able to install the wing mounted fuel gauges? I have them on my 252 and they are quite accurate and easy to use during the fueling process.

To start at empty, you'll need to run a tank dry in cruise. Then land knowing that all that is left in that tank is unusable fuel. Fill it 5 gal at a time and note the position of fuel gauges, wing gauges, or dip stick. 

Fuling of the K was frustrating enough for me to install an EDM-900 and the CiES fuel senders. I also refreshed the wing mounted gauges as well ($40 from LASAR). After all this and running tanks dry occasionally to verify, I'm very confident in my fuel situation at all times.

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Not a Mooney Driver (yet) but I'd recommend sitting down and consuming some of Mike Busch's articles posted on the "Savvy Aviator" website.  There is a ton of information regarding the relationship between FF, Timing, EGT, CHT, ICP, and TIT, among other things.  His many articles may help point you in the right direction for some of your questions and diagnosing problems.  Sounds like you may benefit by ensuring your FF's are even across all cylinders.  Very possible that #2 is running lean while #3 is rich.  Then again, you may also have an issue with your timing (retarded vs advanced).  

There is also some great reading on the Red Fin/Red Box....and why leaning beyond 65% power should be done with ICP in mind.  

 

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+1 for Mike Busch's webinar info. I disagree with him on a few issues, but generally he is EXTREMELY knowledgeable and helpful.

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46 minutes ago, Utah_Pilot said:

Not a Mooney Driver (yet) but I'd recommend sitting down and consuming some of Mike Busch's articles posted on the "Savvy Aviator" website.  There is a ton of information regarding the relationship between FF, Timing, EGT, CHT, ICP, and TIT, among other things.  His many articles may help point you in the right direction for some of your questions and diagnosing problems.  Sounds like you may benefit by ensuring your FF's are even across all cylinders.  Very possible that #2 is running lean while #3 is rich.  Then again, you may also have an issue with your timing (retarded vs advanced).  

There is also some great reading on the Red Fin/Red Box....and why leaning beyond 65% power should be done with ICP in mind. 

 

18 minutes ago, DonMuncy said:

+1 for Mike Busch's webinar info. I disagree with him on a few issues, but generally he is EXTREMELY knowledgeable and helpful.

Better yet, get in that 231 and fly it to Ada, OK to attend a weekend APS seminar at GAMI. You can also get JeanPaul from GAMi to go up with you in your 231 and see first hand what's going on.  Unless the value of that TSIO360 engine is just pocket change for you, I'd want to know how to fly it as to get the most hours of service out of it. 

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That’s alot of questions.  I am short on time at the moment.  Let my just start with question 1, why is the #2 cylinder hotter than the others during the climb, and the related question, why is it right in line at cruise.  CHT is driven by a number of factors.  The three primary ones are (1) power setting (how much %HP is the engine making),(2) fuel/air ratio (LOP or ROP and how far), and (3) cooling.  You can have numbers 1 & 2 completely under control, but if the cylinder is sitting in an enclosed space receiving no air to cool with, it will run hot.

Cyl 2 is the furthest back on the engine, and on the side that receives the least airflow.  Look at the intake holes in your cowling the next time you pre-flight, do you notice something partially blocking one hole and not the other?  Cooling might be something that can be fixed by adjustments to your baffling, but mainly it is just the geography of the engine.  My cyl 2 also runs hot, and during the climb I will tolerate higher temps in that cylinder.

I assume you are climbing with cowl flaps full open, that’s what you should be doing.  What you see is about what I see.

Then why does #2 fall into line with the others at cruise?  You close the cowl flaps, which changes the airflow, and your TAS increases, and so your airflow changes and increases.  You also lower the power setting.  

So what you see on #2 is not unusual for this engine.  

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OK, here goes.  Answers are in red.  

Cruise (LOP) - After a minute of leveling off/speeding up/cooling off, being one of the cool kids, I then go for the big mixture pull to go LOP. I don't linger about the move in any sense, but I've noticed that my TIT reading will go near/above 1700 during the (rapid) transition. By the time I've pulled back to about as lean as the engine will run smoothly, I'm at something like 33-34", 2500, 1550 TIT 11.5-11.7 GPH, flaps closed. Cylinder temperatures are cool as a cucumber - #3 is the hottest CHT at 350, #2 now is the coldest cylinder at 280, EGT's are in the 1400's.

I would make 11.5 my power limit.  That's 75% power LOP.  I would not go over that.  Make your setting 11.3-11.5.  It does drift a little.

1. LOP or absolute temperatures? I've read @jlunseth's epics on how you really have little to no idea of what 'peak' is b/c of the mechanism of the Merlyn's. I'm also confused whether I should be paying more attention to leaning off CHT/EGT as GAMI seems to suggest or TIT as the POH does. If I'm looking for, say, 50 LOP TIT, isn't that 1650? If I touched nothing else aside from mixture, I could in theory be 60 degrees LOP CHT, 120 degrees LOP EGT and 130 degrees TIT at 34-36". I'm flying as per settings in the other threads, but can't square the LOP temperatures against maximum power settings.

According to the GAMI/APS people, degrees lean of the EGT closest to peak is the right way to do it.  That said, once you have established a good power setting it does not make much difference what markers you use to get back there.

There is a way to determine degrees LOP with a fair degree of accuracy, and that is to do the "big pull" to get over to LOP operations, and once you are there, use the ROP lean function on your JPI.  The lean function does not know if you are ROP or LOP.  In JPI parlance, "ROP lean function" just means the lean function determines the first cylinder to peak rather than the last cylinder to peak, and if you are already over on the lean side and then enrich the mixture to get to peak, the first cylinder to peak is the one you want.  You can determine a peak from that, and then lean back until you are the degrees LOP that you want.

2. Why is cylinder #2 the hottest on climbout, but the coolest LOP? Vice versa for cylinder #3?  Air flow changes when you close the cowl flaps for cruise, and power settings change.

3. The engine is rated to deliver 100% power continuously, yet I've been admonished that 12 GPH LOP (which is 78% power) is in the "red fin/red box" and I shouldn't pull that much power LOP. If the temperatures at that setting are essentially the same as above, why is it any different/more harmful?

This is the basic premise of the LOP/ROP and leaning issue.   Stoichiometric mix is that mix where there is exactly the correct proportion of fuel and air, so that all of the fuel and all of the air is burned during the combustion event.  Nothing is perfect, but that is the theory.  Stoichimetric mix, however, also produces the highest or close to the highest peak Internal Cylinder Pressure.  The fire burns the fastest, in other words.  The idea behind leaning is to slow the fire down.  The total pressure exerted during the combustion cycle is the area under the pressure curve.  That area can be the same or close to the same, with a more moderate rate of combustion, which lowers the peak pressure but spreads the duration out, which produces about the same work but without the high peak.  At the peak of the red box, the peak pressure is not only quite high, it is "spiky," if you see it on a test stand.  The "spikyness" is pre-detonation, which is harmful to the cylinders.  You can slow the rate of combustion down by either adding more fuel, which means that the fire slows because there is insufficient O2 to burn the available fuel (but excess fuel goes out the exhaust), or you can slow it down by leaning the mixture so there is not enough fuel for the available air.  Either works to slow down the rate of combustion and reduce the peak ICP.  Anything in the 12's in our engine is in that red box at a normal cruise power setting.  It may produce lots of power and speed, but it also may produce a top overhaul at 1000-1200 hours.

4. At the settings above, are the other 5 cylinders that are 280-320 CHT too lean/too cool?

There is a "normal operating range" for CHT in the POH and the bottom of the range is 250.  I would not worry about it if one or two cylinders were below that either.  The biggest issue is Oil Temp.  To protect the turbo, that needs to stay above 100 dF, and of course it does that by getting heat from the engine, so there needs to be some heat to keep the OT warm.  In very cold operating conditions I will go ROP and sometimes delve into the red box just to keep operating temps up, but I mean cold, at least below 20 dF on the ground, and really below 0dF, again, on the ground.  It does not matter so much what the OAT is in the higher altitudes, the air does not cool the engine nearly as much.

5. On the ROP side, EGT's/CHT's are relatively even across cylinders. On the LOP side, the EGT difference between #2 and #3 blows out to 180 degrees. Why?

The better question is should you care.  EGT's are a relative temp only - where does the cylinder peak - they are not an absolute temp.  Too many variables in placement of the probe.  You should go on the GAMI/APS website and find the instructions for conducting a "lean test," then do it.  If your cylinders are not peaking within .5 GPH of each other, then either the fuel flow needs adjustment, or you should get in touch with GAMI and exchange out your injectors so your "lean test" results are in that range.  

6. If I accept that my engine is barely able to run LOP in an acceptable power setting, how do I handle a climb say from 10,000 to 12,000, or a strong downdraft? Go back to full takeoff configuration/ROP?

Don't climb LOP.  Temps will go up too much.  I always go full rich, full power, cowl flaps open for any prolonged climb.  If a climb is 2,000 feet or less and you are at cruise at the start of the climb, your stored momentum will help get you up to that level without changing your cruise power setting and without temps escalating too much.  So for short climbs I just leave the mix alone and do the climb, then let the aircraft restore to cruise speed.  The other thing to be aware of though, is that even a 2,000 foot climb will change ambient pressure enough that you will need to readjust your MP and maybe your fuel flow setting.  As you know, the Merlyn does not maintain a fixed MP if ambient pressure changes.

Descent - I pull back to 20" MP, which zings me back to ROP and a low power setting. I have to richen things a few turns to get to peak TIT for descent, but everything seems to generally cool gradually and be happy.

Actually, if you are LOP and pull back to 20" the interlink between MP and fuel flow in the TSIO360 tries to maintain the same fuel/air ratio, in other words, it brings the fuel flow down also, so you are probably still LOP, maybe fuel flow is 7 or 8 GPH.  But you don't care either, you can make any mixture setting you want so long as you are at or below 65% HP.  The ICPs are not high enough to be of concern.  You can operate at peak below 65 if you want.

If I am cruising at a LOP setting I just pull off an inch or so of MP, leave the fuel setting untouched, and tip the nose over into a 500 fpm descent rate.  The increase in airspeed/ram air brings the MP back up pretty quick, and the engine is not working as hard because you are going down hill.  Airspeed will pick up nicely.  Obviously if you are going to penetrate convection or turbulence during the descent you are going to want to slow down, but mostly I just go fast downhill.

Cruise (ROP) - "these engines are just too cattywompus/untuned/etc." you say - just fly ROP.

In my last flight, I was stepped down to 6000 and then had to cruise for 25-30 minutes at that elevation. Given that I've already put myself ROP from the descent above, in my mind, I'm basically flying a normally aspirated plane here. At full rich mixture, however, TIT increases pretty quickly at relatively low MP. Anything above, say, 25", results in a TIT getting near 1600 (at 2500 rpm if that matters). CHT's/EGT's are all 340-350/1400's. IIRC, I'm indicating about 12.5 gph.

Again, you don't care what the fuel setting is at 25"" because you are below 65% HP, but I would lean the mixture out just to avoid clogging the plugs.  I would not run full rich going down hill, you're throwing fuel out without needing to.  

1. Why does a setting of say, 29" MP result in an unacceptably high TIT, but 36" (takeoff) not? If I was in a normally aspirated plane, the engine would be able to pull 27" or so, so I'm barely asking the turbo to do anything.

Because your fuel/air ratios are different.  If you are 29" and a LOP fuel setting in the low 11's, that's different from a full rich setting at 36", but even if, say, you start at 36" and full rich, and then pull the MP back without touching the fuel flow, the fuel flow is going to drop and the fuel/air mixture will change.  That's again because of the interlink in the TSIO360 between MP and fuel flow.  Change one and it changes the other.  I am not sure of the mechanics of it, but nearing full power in the TSIO360, the fuel flow is bumped up faster than at cruise settings.  Conversely, it drops off faster if you pull the MP from a full power setting to a lower setting.  The fuel/air ratio is leaner, which results in the higher TIT.

2. Is "full rich" rich enough in this context?

See above.  I would not recommend 29" and full rich for climb if your TIT is going too high.

3. What's the best way to keep the TIT cool in this situation? I don't have any more red knob to add, and feel like I should be able to get more power out of the engine ROP without making my turbo melt.

More MP.  If the engine is set right, you will get a jump in fuel flow and the engine will stay cool.  Do open your cowl flaps.

4. If I'm having this issue at 6000, would it be worse at higher altitudes with less dense air? If so, how the heck am I supposed to get up to said higher altitudes if LOP barely works and ROP is too hot TIT?

Temps are always warmer and cooling poorer in higher altitudes, that is a truism.  Don't climb LOP, that is an NA maneuver, it is not a good thing in a turbo.  Climb full rich, full power, cowl flaps open.  You will have to adjust MP as you go up because ambient pressure changes and MP will fall otherwise.

Oxygen System - I had occasion to use the onboard oxygen system last night for the first time - a night flight at 12k. I have two of the Oxysaver cannulas, plugged them in, and rotated the oxygen knob "on", and lo and behold oxygen came out.

1. How does one 'set a flow rate'? The ball in the little meter showed "20,000 elevation", but rotating the knob is almost a binary function - either the ball was at 20,000, or it immediately fell to 0.

Mine is the same.  More binary than anything, and I don't find that the "Oxysaver" settings on the meter work. Not enough O2.   I use the regular, non-Oxysaver settings.  

2. I consumed about 1/3 of a tank in 2 hours with 2 passengers. Is that normal/acceptable?

About right, maybe a little high, you can dial it down but if you are not feeling right you need to keep the O2 level up.  Go to the drugstore, buy a cheap oximeter.  Use it.  Keep your percent O2 at or above 96%.  Less than that and you are moving into hypoxia.

430W annoyances

1. I'm using the calculator on my 430W's "AUX" page, and at the cruise settings highlighted above, I'm usually somewhere around 170 kt. TAS. I flew back and forth to PHX from SoCal last night, and head/tail winds were forecast to be about 30kt. Going East, GS was about 200 kt., as expected. Coming back West, GS was 120kt., rarely exceeding 130kt. If anything, the storm/winds were dying down. While it's possible the winds were simply stronger than forecast coming back, I've had the same phenomenon seemingly every flight heading West, where TAS - expected wind > GS. This, obviously, could just be psychological, but I don't remember having the same issues in my previous planes.

Forecast winds are rarely truly accurate.  I get winds aloft on a display in my aircraft and the headwind component based on the difference between TAS and GS, always seems different from what the display is telling me.  The forecast winds aloft also often change direction especially over a lengthy route of flight, when they do that the headwind component changes even if the wind speed does not.

2. I've flown behind 430's almost since beginning of my flying career, but this one hasn't been updated in quite awhile and the firmware is old (v 2.3?). If I change a field, say, to display the VNAV or cross-track error on the main screen, it doesn't save from one power cycle to another. Is this a firmware issue, a battery backup issue, a configuration issue?

Power cycle?  You mean, if you turn the unit off and then turn it on again those changes don't save?  The VNAV does save on mine.  Let me be clear, if I use the menu function to put the VNAV on the primary navigation screen, then that change saves.  If I have gone into the VNAV calculater and put in waypoints, distances, etc., I don't think those save.  I almost never use the cross-track feature so don't know that one.  Could be the firmware.

Fueling annoyances

I have a fuel totalizer and use it. Since you never really know how much the line guy put in, error will build over time. Trying to get a visual indication of how much gas is in the tanks is absolutely befuddling. I have tip tanks. The main tanks have those amazingly annoying anti-siphon valves. To make things even more strange, I'm not convinced that my tanks are symmetrically installed and/or the baffles are equal. For example, one main tank will be filled to the anti-siphon valve, yet (what I think) is an equivalent amount of gas in the other wing has the fuel level far below that, with more apparently having sloshed over to the tip tank. The cockpit fuel gauges will burn down to about 25 gallons indicated (on both sides) and remain there for a long time whilst burning off the fuel in the tip tanks, and then descend from there. I know that the answer here is to drain everything and put in a known amount of gas to have some totalizer certainty, but how do other owners do a visual fuel level check? How do you fill the tanks? What is full? What does a full main tank look like? If I (in theory) had empty mains and filled the tip tanks, how long does it take for the gas to drain down to the mains?

If you are going on a long trip and really need to have as much fuel in the tanks as you can get, go out and help the line guy fill the tanks.  They almost never get it right with the anti-siphon valves.  You can have fuel sitting on top of the valve and it looks like the tank is full, but empty space under the valve and you are 8 or 10 gallons short of full.  The line guy has got to use the fuel nozzle to hold the anti-siphon valve open.  You should "waggle" the wings as he does that, to move air in the top of the tank to the fuel hole so it can exit and be replaced with fuel.  Do that, then set your totalizer to whatever the gallonage is for full tanks in your plane, and you should be at a good number.  My gauges do the same as yours, the gauge is probably good, but the senders in the tanks will stick and then move.  You can have them rebuilt (the senders) or replaced, or just put up with it.  Full, to me, is when the anti-siphon valve has been held open, the wings have been waggled, and the fuel is up to the top ring that the fuel cap fits in.  I am told it is supposed to be to the anti-siphon valve, but that is not full capacity in my tanks.

Edited by jlunseth
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Thank you very much for taking the time to read through and reply to my many, many questions!

I'm getting the fuel flow setup, and fuel injectors cleaned tomorrow. I gave my A&P the intercooler fuel setup parameters. I'm about 2-3 gallons too lean on takeoff for full power, which cascades throughout the flight envelope. I think getting that fixed will get a lot of my temperature-related/speed/power issues, both lean and rich of peak.

Clarifications - I always climb ROP. I wanted to learn if another trip through the "red box" moving from LOP to ROP and back to LOP for a climb was OK.

Re: 430 power cycle - yes, I mean turning the unit (or plane) off, and back on again. Any changes I've made to the field setup reverts. This will be less of an issue in a couple of months post-panel upgrade - of all the things, that's the least annoyance and I'm mostly curious.

Re: LOP and "spikiness" - is what you're saying that the spikiness and ICP is unacceptably high in the red box (at 12GPH) even at temperatures that appear to be X degrees lean of peak?

Re: Oxygen - "I use the regular, non-Oxysaver settings" - what is that? All I have (as far as I can tell) is a single knob that is basically binary in terms of flow. It seems like the built-in oxygen tank has an altitude compensating metering mechanism built in. Is there any setting/control between basically "on" and "off" that I'm not seeing?

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20 hours ago, gsxrpilot said:

Yes, those anti-siphon valves are very annoying. I'd recommend starting at empty and either creating a dip stick or you might be able to install the wing mounted fuel gauges? I have them on my 252 and they are quite accurate and easy to use during the fueling process.

To start at empty, you'll need to run a tank dry in cruise. Then land knowing that all that is left in that tank is unusable fuel. Fill it 5 gal at a time and note the position of fuel gauges, wing gauges, or dip stick. 

Fuling of the K was frustrating enough for me to install an EDM-900 and the CiES fuel senders. I also refreshed the wing mounted gauges as well ($40 from LASAR). After all this and running tanks dry occasionally to verify, I'm very confident in my fuel situation at all times.

Thanks for the tip about the wing mounted gauges. My plane does not have those indicators on the wing, and I was unaware how inexpensive the part is.

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I'm getting the fuel flow setup, and fuel injectors cleaned tomorrow. I gave my A&P the intercooler fuel setup parameters. I'm about 2-3 gallons too lean on takeoff for full power, which cascades throughout the flight envelope. I think getting that fixed will get a lot of my temperature-related/speed/power issues, both lean and rich of peak.

Maybe.  The fuel flow is set at 37” as full power.  If you takeoff at 36” its probably a little lower.  I use 36 by the way.  If its in the 22.5-24 range per the POH you are fine.

Clarifications - I always climb ROP. I wanted to learn if another trip through the "red box" moving from LOP to ROP and back to LOP for a climb was OK.

Yes, its fine.  Just don’t let the TIT exceed the limits, 1650 continous, 1725 momentary, per the POH.

Re: 430 power cycle - yes, I mean turning the unit (or plane) off, and back on again. Any changes I've made to the field setup reverts. This will be less of an issue in a couple of months post-panel upgrade - of all the things, that's the least annoyance and I'm mostly curious.  

Avionics shop can upgrade the firmware.

Re: LOP and "spikiness" - is what you're saying that the spikiness and ICP is unacceptably high in the red box (at 12GPH) even at temperatures that appear to be X degrees lean of peak?

At cruise power settings, that is where the red box seems to be in my engine.  That’s not to say you can’t run all day at 12 GPH and a reduced power setting (below 65%).  By spikyness, I am referring to what the ICP graph looks like when an engine is run on a test stand.  Its actually the other way around, because the ICP is high, that is what creates the red box.  The red box is just a concept to explain the range of fuel/air mix that produces high instantaneous ICPs.  Sort of like hitting the piston with a hammer instead of pushing. 

Re: Oxygen - "I use the regular, non-Oxysaver settings" - what is that? All I have (as far as I can tell) is a single knob that is basically binary in terms of flow. It seems like the built-in oxygen tank has an altitude compensating metering mechanism built in. Is there any setting/control between basically "on" and "off" that I'm not seeing?

I have a valve with the Oxysaver.  It has an air gauge that is a ball in a channel.  The channel has markings in thousands of feet for the Oxysaver, and for non-Oxysaver cannulas.  Maybe that is not what you have.  I use the non-Oxysaver markings.  Maybe yours is different.

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On 3/5/2018 at 12:27 AM, gsxrpilot said:

 

Better yet, get in that 231 and fly it to Ada, OK to attend a weekend APS seminar at GAMI. You can also get JeanPaul from GAMi to go up with you in your 231 and see first hand what's going on.  Unless the value of that TSIO360 engine is just pocket change for you, I'd want to know how to fly it as to get the most hours of service out of it. 

Unfortunately, it seems like there is legal trouble between the APS people.

On 3/5/2018 at 7:36 AM, jlunseth said:

Cyl 2 is the furthest back on the engine, and on the side that receives the least airflow.

Often adding a little bit of baffle seal to separate the aluminum baffle from the cylinder fins adds sufficient airflow to improve cooling at the back of the housing.  However, it seems like you have an A:F ratio issue or perhaps an ignition issue on that cylinder.  Address what others have suggested first.  Once you have a properly trimmed air fuel and spark system, come back to this issue if you have  a persistently elevated cylinder temp on climb and start for terms such as baffle seal, pixie hole etc.

20 hours ago, jlunseth said:

2. I've flown behind 430's almost since beginning of my flying career, but this one hasn't been updated in quite awhile and the firmware is old (v 2.3?). If I change a field, say, to display the VNAV or cross-track error on the main screen, it doesn't save from one power cycle to another. Is this a firmware issue, a battery backup issue, a configuration issue?

My 430 will save the last desired VNAV descent rate and X000 ft MSL (not necessarily AGL because this depends on an airport being present in a flight plan).  If your internal CMOS battery were getting below 2.5 volts, you'd get a "Memory battery Low" warning message and if it died 1) your satellites would take forever to acquire because the unit would not have saved the previous location and time information and 2) you may have configuration dependent connections via RS-232 or AIRINC-429 stop working as that memory is dumped each time the unit powers off.  Not likely in your circumstance.  I'd start with updating the firmware.  Caution - gremlins can and do show up with firmare config updates.  (My photocell started acting funky when we updated the GDL software through the 430W.  Reverted and photocell worked.  Reflashed and photocell not working well.  This likely has to do with a response rate issue in the config getting changed but I've been too lazy to dig through the MM to find the pertinent information). 

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4 hours ago, jlunseth said:

Re: Oxygen - "I use the regular, non-Oxysaver settings" - what is that? All I have (as far as I can tell) is a single knob that is basically binary in terms of flow. It seems like the built-in oxygen tank has an altitude compensating metering mechanism built in. Is there any setting/control between basically "on" and "off" that I'm not seeing?

I have a valve with the Oxysaver.  It has an air gauge that is a ball in a channel.  The channel has markings in thousands of feet for the Oxysaver, and for non-Oxysaver cannulas.  Maybe that is not what you have.  I use the non-Oxysaver markings.  Maybe yours is different.

I have the ball in the channel with markings, but no valve. My current setup goes port --> tube --> ball in channel --> tube --> mustache style cannula. From what I've read, the onboard regulator is auto-economizing.

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20 minutes ago, anonymouse said:

I have the ball in the channel with markings, but no valve. My current setup goes port --> tube --> ball in channel --> tube --> mustache style cannula. From what I've read, the onboard regulator is auto-economizing.

That sounds like what most of us have. You can adjust the "ball in channel" to float about mid way up. Make sure you're holding it right way up. There should be one or two sets of markings on the channel.

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I went on the Aerox website and it looks like they have a somewhat different valve-and-tube setup.  My valve and tube are one unit and a T shape.  It looks like the Aerox system has the tube-and-ball separate from the valve.  It still looks like there is a valve though.  Yes, the POH says that the built in regulator changes flow with changes in altitude, but you can still dial the flow down  with a separate valve.  It saves on O2 use.  Do get an oximeter though, it will tell you what you are doing to yourself.  Helped me come up with settings that work best.  The pilot needs to be on a mask for operations above 18000.

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Check to see what type of CHT probe your JPI monitor uses for the #2 cylinder.   It may be different. The factory or primary gauge  is usually in the #2 cylinder and some JPI installations use an under the spark plug sensor as they cannot remove or replace the “primary” probe.  The spark plug gasket sensors read significantly higher versus the probes in the other seven cylinders.

I agree with what others have said about your fuel setup appearing to be on the lean side,  but the problem may be also compounded by an inaccurate reading if that one cylinder has a different type of probe.

I had an identical problem when I first purchased my K model.  I replaced the spark plug gasket probe with the JPI probe that inserts underneath the factory bayonet. Search for 3/8” JPI CHT probe.

Bill

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wpbarnar makes a good point.  I think it may be different for the "certified as primary" JPI's, which is what mine is (a 930), and the JPI's that are not.  I think that the factory probe must be kept on those that are not, and it is a different type of probe which generally provides a different reading.  That said, what you see on you #2 is about what I see.

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That will be a short term problem for me as I'm having a JPI 900 installed in the next couple of months. I appreciate the information in the mean time and won't stress too much about the #2 cylinder absolute temperature reading.

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