Turbo leaning via EGT

[Fly Boomer]

18 hours ago, LANCECASPER said:

In GA, long term owners and owners groups cut through all the marketing nonsense that promoted unrealistic and unattainable numbers and come up with the way that it makes the most long term economic sense to fly the airplane in real world operations. 

And sometimes we get contributions from other individuals and companies like Mike Busch and the GAMI guys.

[Jetpilot86]

19 hours ago, LANCECASPER said:

That is an ancient 1979 Lycoming manual that was written 17 years before the TIO-540-AF1B engine (Bravo) ever existed and 10 years before the TIO-540-AF1A engine existed (TLS). That booklet was made for the much heavier duty 350hp TIO-540 engines years before this that were put into Piper Navajos, as an example, that share no parts with your engine.

The lighter weight engine used in the Bravo is pushed to the max at 270hp and is used in no other airframe. The closest engine related to it is rated at only 250hp and was used in the Socata TB21.

Lycoming came up with a booklet toward the late 90's that is a little closer to reality, where they used more conservative numbers, but just keep in mind that the people who wrote this and other "official" material are not owners who have the "privilege" of buying cylinders ($3000 each for the Bravo) and overhauling engines ($100,000). I would dispose of that version properly, along with the charts on the visors that came with early M20Ms. 

In GA, long term owners and owners groups cut through all the marketing nonsense that promoted unrealistic and unattainable numbers and come up with the way that it makes the most long term economic sense to fly the airplane in real world operations. 

One other thing: you keep quoting what the MAX numbers are in this and the POH. Hopefully you would never operate a $40,000 car pegged to the redline on the numbers, with the tach, the temperatures, etc, for good reason. Your Bravo engine is worth twice what the average car is today.

Not quite as ancient as you suggest, and does cover the Alpha.
 

The question I’ll try to answer next time I fly is what are the CHT’s when leaning to the lower of 1525° or 125°ROPTIT? Below 400° I would presume with as fuel rich as that setting will be, it probably is at least as conservative as what @donkaye does, if not more. Certainly more CHT conservative than the POH @ straight up 1650°TIT. I’m sure it’s not going to be “economical”. 

[LANCECASPER]

1 hour ago, Jetpilot86 said:

Not quite as ancient as you suggest, and does cover the Alpha.
 

The question I’ll try to answer next time I fly is what are the CHT’s when leaning to the lower of 1525° or 125°ROPTIT? Below 400° I would presume with as fuel rich as that setting will be, it probably is at least as conservative as what @donkaye does, if not more. Certainly more CHT conservative than the POH @ straight up 1650°TIT. I’m sure it’s not going to be “economical”. 

Ok, thanks, the pages you showed on the earlier post showed "1979". 

The -AF1A was a failure with the temperatures they recommended. People were fortunate to get 300 hours from a set of cylinders.

My A & P and I converted the last known -AF1A in the field to an -AF1B in early 2018 on a 1993 M20M that I bought. The original owner had never converted even though Lycoming/Mooney offered a great upgrade price back in 1996 of $5500 including 6 new cylinders, all of the hardware and hoses and 40 hours labor. The thread below follows the conversion starting with the post on January 31, 2018.

 

[Will.iam]

On 12/6/2023 at 7:25 PM, Jetpilot86 said:

I'm curious if you/anyone knows what the max over squared the Bravo's can be run?  My Checkout instructor was a big fan of 2300 as the RPM, especially in the pattern as he said it was an RPM you could use, firewall the MP and not break the engine if you forgot to push the prop in down final.  I need to ask him where he found/heard that number.

2300 comes from a counter weight separation issue that can happen on over square operations with rpm below 2300. Mike bush did an article about it as his 310 has those exact same engines and he talked to the operators of cape air that had these issues. He found they were running them in a certain way that caused that issue and thus disregarded it personally for his operations. But others to be on the safe side will not over square with rpm’s below 2300. So I advise you to read the article about that issue. 

[Will.iam]

On 12/6/2023 at 2:14 PM, Jetpilot86 said:

You are seeing what I’m getting at. From my studies mostly here, there are multiple AND competing/conflicting limits that very likely vary depending on your %HP at that moment. 
Going through all the old papers on my new toy as well last night, it seems the turbo and a couple of cylinders were done around 1500 hours. This on the original engine. Unfortunately, I don’t have the original Engine log to see how the previous, and only owner faired in the 1900TT he had on the plane, or how he operated it, but it seems like he faired better than most on here and certainly better than the other Bravo I’d looked at that went through 3 cylinders in 700 SMOH. With the FOH that came from Lycoming, both the turbo and exhaust are new, and obviously I’m trying to figure out how to get the most out of them without destroying them  

At the end of the day, I’m not as much interested in how someone operates their engine as much as why. Book? Old wives tales? A bunch of technical research? The advanced engine seminars?

With your setup now since you can monitor every cylinder’s egt you need to do a gami lean test to see what your fuel spread is now. As mine is less that .5 gph I know I can run pretty deep lop. But after years of experimenting I now see I could tell if I’m rop or lop at any power setting by just changing the mixture a little more rich and look at the tit. If it goes up I’m lop if it goes down I’m rop. Or if I lean the mixture a little bit and the tit goes up I’m rop if the tit goes down I’m lop. I have found that my limits are bound by heat both cht and tit. Rop gives me cooler tit limits but my cht start hitting 380. If I go lop then my cht’s are good but then I’m hitting my tit limit which personally for me is 1600. In the winter time I can push more power before I bump up against my cht or tit limit compared to when in the summer with higher OAT temps. 

[LANCECASPER]

1 hour ago, Will.iam said:

 Mike bush did an article about it as his 310 has those exact same engines and he talked to the operators of cape air that had these issues. 

Mike Busch has a Turbo Cessna 310 that has Continental TSIO520B engines.

The M20M Bravo has a Lycoming TIO-540-AF1B

[Jetpilot86]

7 hours ago, LANCECASPER said:

Ok, thanks, the pages you showed on the earlier post showed "1979". 

The -AF1A was a failure with the temperatures they recommended. People were fortunate to get 300 hours from a set of cylinders.

My A & P and I converted the last known -AF1A in the field to an -AF1B in early 2018 on a 1993 M20M that I bought. The original owner had never converted even though Lycoming/Mooney offered a great upgrade price back in 1996 of $5500 including 6 new cylinders, all of the hardware and hoses and 40 hours labor. The thread below follows the conversion starting with the post on January 31, 2018.

 

The book covers about a dozen engines.   I pulled all the pages that didn’t discuss the A1FA and that got rid of at least half. 
Keep in mind that I’m not necessarily seeking to change “how things are done”, but how they have been changed and where the documentation that drove that is. There has been made mention of a Bravo document from Lycoming that Mooney didn’t like. I’d like to see a copy of that one. Likely provides the basis for what the “groupthink” is now. 

[Jetpilot86]

4 hours ago, Will.iam said:

With your setup now since you can monitor every cylinder’s egt you need to do a gami lean test to see what your fuel spread is now. As mine is less that .5 gph I know I can run pretty deep lop. But after years of experimenting I now see I could tell if I’m rop or lop at any power setting by just changing the mixture a little more rich and look at the tit. If it goes up I’m lop if it goes down I’m rop. Or if I lean the mixture a little bit and the tit goes up I’m rop if the tit goes down I’m lop. I have found that my limits are bound by heat both cht and tit. Rop gives me cooler tit limits but my cht start hitting 380. If I go lop then my cht’s are good but then I’m hitting my tit limit which personally for me is 1600. In the winter time I can push more power before I bump up against my cht or tit limit compared to when in the summer with higher OAT temps. 

This is what I’ve been suspecting for a bit, but with no previous data monitoring could not confirm. Now I need to hook up the rest. 
I’m also beginning to suspect one of the core issues of either the Alpha or Bravo is that, courtesy of the AFM, TIT has been prioritized at the expense of CHT with the side effects we’ve seen with the cylinders. Write the manual with TIT mentioned in passing as CHT has been and owners are blowing through turbo’s instead. It’s not that one is more important, both are critical, more so than in other engines since this one is pushed so hard by Mooney, to get the performance they wanted to market when it appears it replaced the PFM. 

[jlunseth]

On 12/9/2023 at 9:59 AM, Jetpilot86 said:

Injectors (non GAMI), and Champion plugs are new with the engine, but as soon as I have the data recording dialed in, let the injector & plug debate begin!

 

Healthy spark is very important to LOP operations. The mixture is harder to ignite. Most people find that fine wires work best. If I fly a lot during a given year from one annual to the next, sometimes the engine’s LOP performance is not as smooth toward the end of the year, until the annual is done and the magnetos get a going over. Then all is good again.

[LANCECASPER]

 It’s not that one is more important, both are critical, more so than in other engines since this one is pushed so hard by Mooney, to get the performance they wanted to market when it appears it replaced the PFM. 

The M20M wasn't to replace the M20L (Porsche). The M20L was more of a novelty, with the name and the FADEC controls. The Porsche only had the performance of the J, not even close to the K (252). It turned out that Porsche just didn't know what all it would take to support an aircraft engine and wasn't doing a good job of it. When Mooney pulled out, it wasn't long before Porsche pulled out of GA completely and even stopped supporting the engines they had in the field. The M20L really didn't fit in the Mooney line-up, even though they sold 40 the first year since the name "Porsche" was attached. It was dead in the water the minute the announcement was made about the upcoming TLS, and after only 1 sale in 1989 it was discontinued part way through that year.
Mooney's mantra from 1986-1989 was "a new model every year". The 252 came out in  1986. The J had a complete make-over in 1987 (24v, rounded windows, some of the aerodynamic mods from the 252). The first long body (M20L Porsche ) came out in 1988. 
They were trying to compete in a lot of different markets. They started to work on the TLS (Turbo Lycoming Sabre) in early 1987 together with Lycoming and  many now agree that they rushed to market with that engine (-AF1A), introducing it in less than 2 years in 1989. With the M20M, Mooney was trying to compete with the Piper PA46 Malibu/Mirage in terms of performance. An unintended consequence of the M20M was that Mooney hardly sold any 252s once the M20M was introduced. In fact the Mooney Direct sales team took quite a few 252s on trade for a TLS - with owners wanting the fastest Mooney.  In 1990 they sold only 10 252s - they had sold 91 in the year of 1987. So they dropped the K thinking that they didn't need to compete against themselves (which once the hype of a new model was over they wouldn't have been anyway). After the TLS engine problems started to surface in 1991 and on, Mooney/Lycoming were getting a lot of backlash from the owners. To Lycoming's credit they helped out some vocal owners with reduced prices on cylinders and helped with labor until they had a solution. (Later starting in 1997 Mooney sold the 36 of the K models again for two more years. It fit nicely in their line-up, priced highest to lowest: Bravo, Encore (K), Ovation, Allegro (J). New ownership wanted to re-invent the wheel and they scrapped the J & K after 1998 )
The solution Lycoming came up with, the wet-head cylinders, and coming to the MAPA convention every year to preach about more conservative temperatures, worked for the faithful who listened. Those two approaches made it possible to get to TBO with the engine. The M20M meeting at those conventions turned from one of discord to again praising the model. You can scour through Mooneyspace and about once a year someone who is a new M20M owner feels like if it's in the book that's the way they should do it. Buying a set of cylinders in 12-18 months usually helps clear up that thinking. For some reason they usually don't cook the Turbo but they do go through the exhaust pretty fast with high TIT.
The six cylinder engine/McCauley prop is not the smoothest combination, but once you get used to it, it's fine.  I think it has a lot to do with the intake not being balanced. Many mechanics unfamiliar with this engine do not have the fuel flow set up right - not enough fuel on take-off. Hartzell has been working for years on a Top Prop for the M20M. If and when they do that, it will help performance by around 7 knots, I'm guessing, based on other applications of that prop, and will probably help smoothness as well, not to mention taking a few pounds off of the nose.

[Will.iam]

Too bad the top prop will not be for the K model too. My only option to get a lighter prop than my MacCauley prop is to go with the MT prop. 

[Pinecone]

Hartzell is working on a composite 3 blade for the Mooneys.  It will be for the Ks and more.

[kortopates]

21 hours ago, Pinecone said:

Hartzell is working on a composite 3 blade for the Mooneys.  It will be for the Ks and more.

So they've been saying for quite ahile now.

So I have the MT-composite prop.

I was worried I would lose some cruise speed but so far I can't see and noticeable loss.

But its climbs amazingly better, jumps off the runway sooner and requires a significantly steeper attitude to get to Vx, (I haven't yet been comfotable to actually find the pitch attitude that doesn't exceed Vx since losing an engine at that pitch attitude would be to unforgiving). Evenbtually I'll do some testing with some altitude.

Still need to measure best glide speed range but so far doing a pwr off 180's from the usual spot still works fine and that's without pulling the prop back - which I only due gliding to an airport. But the physics says its got to be less than what the original 2 blade McCauley and I need to update by glide ratio. 

[Fly Boomer]

On 12/13/2023 at 11:14 AM, LANCECASPER said:

Buying a set of cylinders in 12-18 months usually helps clear up that thinking.

That made me laugh.

[Fly Boomer]

On 12/13/2023 at 11:14 AM, LANCECASPER said:

With the M20M, Mooney was trying to compete with the Piper PA46 Malibu/Mirage in terms of performance.

Also, they were competing with Rocket Engineering.  Before the M, a Rocket would leave everything else in the dust.

[wombat]

[Will.iam]

On 12/14/2023 at 4:22 PM, kortopates said:

So they've been saying for quite ahile now.

So I have the MT-composite prop.

I was worried I would lose some cruise speed but so far I can't see and noticeable loss.

But its climbs amazingly better, jumps off the runway sooner and requires a significantly steeper attitude to get to Vx, (I haven't yet been comfotable to actually find the pitch attitude that doesn't exceed Vx since losing an engine at that pitch attitude would be to unforgiving). Evenbtually I'll do some testing with some altitude.

Still need to measure best glide speed range but so far doing a pwr off 180's from the usual spot still works fine and that's without pulling the prop back - which I only due gliding to an airport. But the physics says its got to be less than what the original 2 blade McCauley and I need to update by glide ratio. 

How are your blades holding up? I mentioned the MT-prop to an A&P that said the blades are still cracking paint and if the governor goes out there is not a stop like on a Hertzel prop to prevent over speed. Sounded like he favored Hartzell over MT or just had some bad experiences with MT which I know they had issues in the past just was wondering if they have those issues ironed out now a days. 

[ChrisH]

Has anyone installed the scimitar on a Bravo? 

https://hartzellprop.com/stc-approved-for-hartzell-propeller-3-blade-mooney-bravo-prop/ 

[kortopates]

How are your blades holding up? I mentioned the MT-prop to an A&P that said the blades are still cracking paint and if the governor goes out there is not a stop like on a Hertzel prop to prevent over speed. Sounded like he favored Hartzell over MT or just had some bad experiences with MT which I know they had issues in the past just was wondering if they have those issues ironed out now a days. 

The paint was an issue some years ago but has been resolved quite awhile back. I queried several Mooney owners about the paint, all with over 5 years of service, and every one said the paint was still in pristine condition.
Every prop is made with stops so that sounds like a red herring to me.
The real issue for me was servicing the MT prop. A few years back the issue was that you had to send the prop to MT in FL for servicing, being on the west coast that was a major issue for me. But now they have a network of shops across the country that service them including my favorite prop shop in Northern CA whom I prefer to use and does pick-ups in SOCAL. With that resolved I was ready to be a MT prop owner.


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[LANCECASPER]

8 hours ago, ChrisH said:

Has anyone installed the scimitar on a Bravo? 

https://hartzellprop.com/stc-approved-for-hartzell-propeller-3-blade-mooney-bravo-prop/ 

Wow I wasn't aware that it got approved. I sold my Bravo in 2021 and bought an Acclaim so haven't been paying attention. Early on they were claiming a 7 knot cruise improvement, sorry to see that they ended up with less than half of that.

[kortopates]

Wow I wasn't aware that it got approved. I sold my Bravo in 2021 and bought an Acclaim so haven't been paying attention. Early on they were claiming a 7 knot cruise improvement, sorry to see that they ended up with less than half of that.

Apparently that’s without prop de-ice too which i assume is standard on every Bravo, since they say electric prop de-ice isn’t yet approved, just FIKI. Since adding the electric prop de-ice boots is going to cost a couple knots it sounding like a wash in cruise performance but significantly better climb performance.


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[LANCECASPER]

2 hours ago, kortopates said:

Apparently that’s without prop de-ice too which i assume is standard on every Bravo, since they say electric prop de-ice isn’t yet approved, just FIKI. Since adding the electric prop de-ice boots is going to cost a couple knots it sounding like a wash in cruise performance but significantly better climb performance.

I had three Bravos and didn't have a hot prop on any of them.

[Fly Boomer]

8 hours ago, kortopates said:

Apparently that’s without prop de-ice too which i assume is standard on every Bravo, since they say electric prop de-ice isn’t yet approved, just FIKI.

I thought TKS FIKI included prop slingers?

[LANCECASPER]

1 hour ago, Fly Boomer said:

I thought TKS FIKI included prop slingers?

According to the above link there are three ways you can buy the prop: without any ice protection, with a TKS protection kit and with electric de-ice.

[donkaye]

9 hours ago, LANCECASPER said:

I had three Bravos and didn't have a hot prop on any of them.

Having had it for the 31 years I've owned my Bravo, I have to say it is probably one of the most expensive items to maintain on the airplane.  While I've never had to use it, I have turned it on on occasion and i am glad to have it from a comfort level point of view.