201 to Bravo?

[donkaye, MCFI]

9 hours ago, 1Germaican said:

@donkaye did all of your engines make it to TBO?  Did you operate them all the same?  What lessons did you learn from operating experience?  Curious minds want to know,

Thank you,

To answer a couple of your other questions, the addition of an engine monitor made engine management a lot easier.  First off, I added Gami Injectors on the 2nd and 3rd engine.  In spite of that my engines have not run well LOP, so I run ROP.  Running ROP, TIT should be a minimum of 100°F ROP when operating above 65% power to keep internal pressures to an acceptable level (reference the Advanced Pilot Training Course given by Gami).  I tend to operate richer, so I keep the TIT below 1600°F.  At lower power setting I'll lean to peak TIT.  Due to the high operating temperatures of turbochargers, I now proactively overhaul the turbo and watergate at midtime.  Main Turbo in Visalia, Ca. did mine and they are reasonable.

[Tx_Aggie]

On 1/3/2022 at 1:56 PM, Danb said:

I’ve had two J models for about 20 years and 15 years in my Bravo, I see no difference in fun or flight characteristics between them except the Bravo is different in landing, or it’s me getting older. Did change from my J’s which I loved to the Bravo due to taking many more long flights, my wife like going faster albeit more expensive 

I can relate to this, we picked up our J to make the journey from west Texas to Houston area more reasonable. But with the extremely reasonable fuel burn and in my opinion low fuel bills, we’ve started journeying further and more regularly to the Florida pan handle. The J can make it in decent time outbound but necessitates two stops usually heading back west. Which I think could be reduced to one stop with a higher output bird. The Bravo would be a great move, and I enjoy considering it as a next option. However, knowing the extra expense, I think at this point I just can’t quite make the jump yet. Thanks for the input!

[Tx_Aggie]

On 1/6/2022 at 5:39 PM, donkaye said:

I've been enjoying the posts of CitationMax on YouTube.  His family started out with a Cirrus and quickly moved to a Citation M2.  After a short time they found the range of the M2 unsatisfactory and stepped up to the Citation CJ3+ to accomplish their required missions.  The same can be said for the Mooneys.  Each satisfies their specific goals.  Once you have moved to the turbocharged models you wouldn't want to move back.  In my opinion it's absolutely ridiculous that the Bravos should be priced the way they are.  That does, however, provide opportunities for the smart buyers.  For a well trained pilot the Bravo is no more difficult to fly that a J.  It's just different.  If you're flying like a pro, you shouldn't even notice control pressure differences (there are some) because you will be flying with control pressures and not just jerking the airplane around like an amateur.  I can't tell you how many times I've had to teach otherwise good pilots how to fly with "grace", and not like an aerobatic pilot.

I've had my Bravo for 29 ½ years.  A turbine would not be unreasonable.  I choose to stay with my Mooney because it satisfies my needs and wants.  That says it all.

 

I agree and enjoy flying professional. Making smooth, proactive flying adjustments and communications with atc while flying IFR is a lot of fun in my opinion. Particularly in and out of Bravo airspace and in and among jet traffic! Go Mooney!

[rbp]

21 hours ago, donkaye said:

The red Lycoming Engine manual that should have come with your plane.  As you know, the POH doesn't show settings as a percentage of power.  In fact, if you used some of it's settings, the engine wouldn't make TBO.

My book didn't have chart. it has an in-flight procedure for determining 75% based on peak TIT and fuel flow, which I did 20 years ago and came out with 30/24. The book is in the plane, which is not handy, so i can't reproduce it here. I'd love to see a scan/screenshot of the page in your book.  When I get the new EIS system in, i'll recalibrate.

[rbp]

21 hours ago, donkaye said:

my engines have not run well LOP

Running LOP is specifically disallowed by the Lycoming af1b manual. I'd quote it, but I don't have the book in front of me.

Can you answer the question about whether or not your engines ran to TBO?

[LANCECASPER]

2 hours ago, rbp said:

Running LOP is specifically disallowed by the Lycoming af1b manual. I'd quote it, but I don't have the book in front of me.

Can you answer the question about whether or not your engines ran to TBO?

[donkaye, MCFI]

2 hours ago, rbp said:

My book didn't have chart. it has an in-flight procedure for determining 75% based on peak TIT and fuel flow, which I did 20 years ago and came out with 30/24. The book is in the plane, which is not handy, so i can't reproduce it here. I'd love to see a scan/screenshot of the page in your book.  When I get the new EIS system in, i'll recalibrate.

From the Lycoming Manual Page 3-84 at Standard Conditions.  As you know, the AF1B is the AF1A with oil injection.

20220109_SEA LEVEL PERFORMANCE.pdf

[rbp]

do you have the whole manual? is there a page which has a procedure for determining high cruise power setting based on fuel flow and TIT?

[rbp]

"Running LOP is specifically disallowed by the Lycoming af1b manual. I'd quote it, but I don't have the book in front of me."

can you also see if it LOP is approved for operation?

sorry to ask you to look it up. if you have a PDF of the manual, please send and I'll do it myself

[tls pilot]

The Lycoming Operators manual (red binder) should be with the manuals

A simple search found this

https://www.lycoming.com/sites/default/files/60297-23P.pdf

 

[donkaye, MCFI]

3 hours ago, LANCECASPER said:

1st Engine: 2,295 hours or 295 hours past TBO.

2nd Engine 1,600 hours, then replacement due to Shop error.  I'm confident it would have made it to TBO.

3rd Engine only has 324 hours on it since replacement in 2019.

[carusoam]

The engine manual is good to have…

The POH is based on the engine manual…

The POH rules!

The engine manual is full of other interesting details that an owner wants to know about…. Just too many pages that don’t belong in the POH…

 

See if you can get electronic copies of all… just for reference, while sitting at the kitchen table…. Best if they are actual electronic copies of your actual POH… 

Best regards,

-a-

[donkaye, MCFI]

1 hour ago, tls pilot said:

The Lycoming Operators manual (red binder) should be with the manuals

A simple search found this

https://www.lycoming.com/sites/default/files/60297-23P.pdf

 

This manual mimics the data in mine for the TIO540AF1B engine, but a later version.  I like it because it is searchable and information is easily located.  All your questions are answered there including your comment that the engine should only be operated ROP.  The Advanced Engine Management Course has arguments against the restriction, but I choose to follow Lycoming's recommendation.

[LANCECASPER]

On 1/9/2022 at 1:32 PM, carusoam said:

The engine manual is good to have…

The POH is based on the engine manual…

The POH rules!

The engine manual is full of other interesting details that an owner wants to know about…. Just too many pages that don’t belong in the POH…

 

See if you can get electronic copies of all… just for reference, while sitting at the kitchen table…. Best if they are actual electronic copies of your actual POH… 

Best regards,

-a-

In this case the document was written well after the POH, so people who continue to insist on flying by the POH (1750 TIT) still burn up their engines. When people buy a used Bravo they have never heard of this manual. This is another reason I used to enjoy the MAPA seminars at homecoming where I first learned about the Lycoming manual.

[rbp]

6 hours ago, donkaye said:

From the Lycoming Manual Page 3-84 at Standard Conditions.  As you know, the AF1B is the AF1A with oil injection.

 

using Charle's law, its easy to see why 30" of MP @1550 is lower than 78% power (as per the chart). Perhaps that why you can run your engine at 1600TIT

[donkaye, MCFI]

19 minutes ago, LANCECASPER said:

In this case the document was written well after the POH, so people who continue to insist in flying by the POH (1750 TIT) still burn up their engines. When people buy a used Bravo they have never heard of this manual. This is another reason I used to enjoy the MAPA seminars at homecoming where I first learned about the Lycoming manual.

Surprisingly, even this latest manual shows the Maximum TIT for  the Bravo to be 1750°F.  See Page 3-9 Notes

[LANCECASPER]

1 hour ago, donkaye said:

Surprisingly, even this latest manual shows the Maximum TIT for  the Bravo to be 1750°F.  See Page 3-9 Notes

Wow

[aviatoreb]

What is it about the Bravo turbo that made them think that 1750 is ok in the first place?  Is the turbo itself specially built?  Ceramic coated or something to wick heat?  (and all the resulting burning out the tit probes, the exhaust valves, exhaust tubes, etc aside). I am just asking what was their thinking and what engineering did they have to put forward 1750 in the first place where most turbo engines limit at 1650?

[LANCECASPER]

Lycoming already had some turbo engines at 1750, like the TIO-540-AE2A in the Mirage, which is also too high of a temperature for that set-up. (Later those owners also got info from Lycoming to lower the TIT to 1650)

Legend has it that when the TLS started going through cylinders early on in 1990 and 1991 (before the Bravo conversion was introduced in '96) Lycoming started to recommend lower power settings and lower TIT (1650) but Mooney wanted the speed and the range that 1750 provided and there was a lot of pushback and a lot of cylinders replaced. Because of this ongoing finger-pointing between Lycoming and then Mooney President Jacques Esculier, in 1992 he vowed never to use another Lycoming engine in a new Mooney model developed after that. Of course he was gone in a year or two, but all Mooneys developed after that, the Ovation, Encore and Acclaim all used Continental engines. But to me it just shows that asking too much of any engine, Lycoming or Continental, is going to lead to problems. Bravo engines that are run at reasonable temperatures last a long time. 

 

[1Germaican]

Very interesting indeed.  I’m so glad this forum exists!  I am a little bit wiser for everyone’s input.  Thank you.

[PaulM]

13 hours ago, aviatoreb said:

Bravo turbo that made them think that 1750 is ok in the first place?

The exhaust for the AF1A/B was built from Iconel, which has a higher temperature yield point.    All of the AF1A and AF1B design tweaks were so that Mooney could fit the most power in the smallest space and advertise that top speed, but as you see you need to run at at 80% power, and at an exhaust temperature that burns up the exhaust.  The welds at the 1st bend seem to fail first.   (I also have a toasty TIT probe on my shelf). 

You can either run it at a good power, but ROP and use up fuel, or find the "peak" power that keeps the TIT below 1650 for best efficiency.   

[aviatoreb]

23 minutes ago, PaulM said:

The exhaust for the AF1A/B was built from Iconel, which has a higher temperature yield point.    All of the AF1A and AF1B design tweaks were so that Mooney could fit the most power in the smallest space and advertise that top speed, but as you see you need to run at at 80% power, and at an exhaust temperature that burns up the exhaust.  The welds at the 1st bend seem to fail first.   (I also have a toasty TIT probe on my shelf). 

You can either run it at a good power, but ROP and use up fuel, or find the "peak" power that keeps the TIT below 1650 for best efficiency.   

Thanks!  I was always curious about that.  What kind of temps are your egt at if you were to run TIT at 1750?

[PaulM]

30 minutes ago, aviatoreb said:

Thanks!  I was always curious about that.  What kind of temps are your egt at if you were to run TIT at 1750?

lower 1600's...   with the power back it runs in the upper 1500's. 

[Bravoman]

 As an aside, it is also important to change oil every 25 hours when running a turbo charged engine.  Although a little bit anecdotal, I believe that that goes far to help reaching TBO without having to change cylinders or do a top overhaul.

[LANCECASPER]

7 hours ago, Bravoman said:

 As an aside, it is also important to change oil every 25 hours when running a turbo charged engine.  Although a little bit anecdotal, I believe that that goes far to help reaching TBO without having to change cylinders or do a top overhaul.

Very good point. Lycoming specifically calls out this engine as requiring 25 hour oil changes. Mooney echoes that in the Maintenance manual. At a MAPA seminar 20+ years ago ('97 I think) the Lycoming rep mentioned that with the heat that this engine produces the tests that they had done on the oil showed dramatic degradation after 25 hours. The oil in the Bravo engines has the added duty of wicking away the heat from around the "hot section" (exhaust valve guides). Not sure how hot that oil gets momentarily as it's passing through that area, but I would guess it plays a part in breaking it down.