Lop Bravo

[Danb]

Guys I hate to beat a dead horse but seem to be starting to understand this Lop Rop topic.. I have seen lots of data from Lycoming 4 bangers. Conti's big block engines..my question re: Bravo's big bore 6 turbocharged stock injectors etc...Do we have any Bravo drivers who are running Lop with stock injectors and what is the info. Since I burn about 18. Gal hr. At $6.60+ per gal? some savings would be nice I fly most of my missions around 12-15000 ft. Thanx. Dan

[carqwik]

Mine won't run LOP with the stock injectors...it prefers 100 ROP.  Better way to save gas in the Bravo is dial the MP back to 27" or less and run closer to peak on the rich side....although you will give up some speed.  You can get the fuel flow to 16 gph or less...

[fantom]

Don Kaye, with his 10,000 or so Mooney hours is a long time Bravo owner. He spent untold hours and dollars trying to get his bird happy LOP. It never was, even with GAMI injectors.

Maybe he'll comment, but in the meantime pulling the power back and staying near peak is sound advise.

[gjkirsch]

Mine won't run LOP with the stock injectors...it prefers 100 ROP.  Better way to save gas in the Bravo is dial the MP back to 27" or less and run closer to peak on the rich side....although you will give up some speed.  You can get the fuel flow to 16 gph or less...

What TIT are you peaking at with the lower power settings?  I don't want to run hotter than 1600TIT to protect the exhaust and turbo and see an almost linear drop in speed with power setting.  FWIW, I get between 9 and 10 mpg. 

[Skywarrior]

What TIT are you peaking at with the lower power settings?  I don't want to run hotter than 1600TIT to protect the exhaust and turbo and see an almost linear drop in speed with power setting.  FWIW, I get between 9 and 10 mpg. 

 

At what power setting? What TAS?

[Danb]

My TIT are in the 1575 which is what I was told when I rec'd factory training when I bought it in 2006,  generally at 13000 ft  32 inches over 2400 gives me about 198- 202 all my temps. stay in the good (cool)  range..I don't approach 400 cht until  over say 17000 on a std. day. I have been running for the last yr. or so 30 in. over 2400 at 14000 gives me a little over 190 and about 16.5 gal. and 360-375 cht's.. With long range tanks seems like we can fly forever, My 1st. yr. I flew at 34/24 and 19 gal and only picked up a couple knots, I'm not sure where most Bravo guys fly and all the input would be great...all cal. compressions are say 74+ and it has 600+ hours..Thanx for the help  Dan

[Danb]

Chuck, I do believe like you do the most important thing is heat kills these engines as does shock cooling...I pay immense time watching worrying about the temps. which is why I initially wondered about LOP in our Bravos

[AndyFromCB]

My TIT are in the 1575 which is what I was told when I rec'd factory training when I bought it in 2006,  generally at 13000 ft  32 inches over 2400 gives me about 198- 202 all my temps. stay in the good (cool)  range..I don't approach 400 cht until  over say 17000 on a std. day. I have been running for the last yr. or so 30 in. over 2400 at 14000 gives me a little over 190 and about 16.5 gal. and 360-375 cht's.. With long range tanks seems like we can fly forever, My 1st. yr. I flew at 34/24 and 19 gal and only picked up a couple knots, I'm not sure where most Bravo guys fly and all the input would be great...all cal. compressions are say 74+ and it has 600+ hours..Thanx for the help  Dan

 

30/2300 seems to be a sweet spot where I burn about 15.5 for 185knots at 12,000, or about 195 at 17,000 to 18,000. Running Bravo LOP seems to be an excercise in futility IMHO. It works at lower power settings where you can esentially get close to J efficiency, at lets say 24/2200, 155 knots at altitude for about 11 gph, but I've never been able to go LOP at higher power settings. This is one funky engine that peaks different cylinders in different order at different power settings.

 

I tend to run mine like the previous owner, right at 1650 and so far the turbo and exhaust have done just fine in the last 800 hours.

[Marauder]

Speaking of high altitude flying, I have a question for you oxygen suckers... How mushy are the controls on your planes at those altitudes? I had my F up to 14k once I really didn't like the Cessna 172 feel I felt. Is this true for the turbo versions as well?

[mike_elliott]

Speaking of high altitude flying, I have a question for you oxygen suckers... How mushy are the controls on your planes at those altitudes? I had my F up to 14k once I really didn't like the Cessna 172 feel I felt. Is this true for the turbo versions as well?

 

not mushy at 200kts!

[Danb]

Rock Solid like Mooneys are supposed to be..200 seems like 150 only a dry nose yuck

[KSMooniac]

I've had my J to 17,500 and felt no control differences.

 

Hopefully Don K will chime in on this thread eventually, but I believe his original engine ran fine LOP and he started running that way after taking one of the Advanced Pilot Seminars.  Fast forward some time after he exchanged it for a factory overhaul, and the new absolutely would not run smoothly LOP, and no amount of fiddling seemed to correct it.  The GAMI folks said some will, some won't, and it is a bit of a mystery and I don't believe they have ever gotten to the bottom of it with that particular engine.  

I would never want an engine, especially a turbo, that could not reliably run LOP as the reasons are too compelling to run ROP as standard practice.

[fantom]

I had my F up to 14k once I really didn't like the Cessna 172 feel I felt.

 

Why did you disconnect the A/P?

[Hank]

Speaking of high altitude flying, I have a question for you oxygen suckers... How mushy are the controls on your planes at those altitudes? I had my F up to 14k once I really didn't like the Cessna 172 feel I felt. Is this true for the turbo versions as well?

I took my C to 15,000 one summer afternoon (calculated later to be 18,800 DA), and she was rather mushy. Didn't climb worth a durn, either, the last few thousand feet were painfully slow with a few level offs to build speed back up. Handling was far from crisp. But it counted as oxygen training, and gave the opportunity for several emergency descents, both high speed and high rate.

As for Bravos and LOP, I've always heard that you're just SOL. But at least you're fast and can go high!! Then again, my C doesn't do LOP either . . .

[Marauder]

Why did you disconnect the A/P?

Good question!

[aviatoreb]

I sat with awfulcharlie in his Bravo on a wonderful flight around Switzerland in the fall of 12.  I observed him operating LOP and it ran very nicely that way.  I was really impressed. I will let him pipe in with his operating parameters.

[carqwik]

Back to the question...at 27"/2400 at 10k I run at about 60-75 ROP which is about 1600 on the TIT.  Get about 170 kts TAS...and my Bravo is definitely not the fastest in the bunch.  FF is about 16.4 gph at the start and goes down slowly over time to settle around 15.5 gph.  At 30/2400, I get about 178 kts at 100 ROP but fuel burn starts out about 3 gph higher around 19 or so.

 

At all power settings, speed goes up with altitude...the Bravo likes the high teens alot where mine will do 198-200 kts or so at 30/2400.  The Bravo handles just fine at those altitudes although George does most of the flying up there.

[mike_elliott]

I've had my J to 17,500 and felt no control differences.

 

Hopefully Don K will chime in on this thread eventually, but I believe his original engine ran fine LOP and he started running that way after taking one of the Advanced Pilot Seminars.  Fast forward some time after he exchanged it for a factory overhaul, and the new absolutely would not run smoothly LOP, and no amount of fiddling seemed to correct it.  The GAMI folks said some will, some won't, and it is a bit of a mystery and I don't believe they have ever gotten to the bottom of it with that particular engine.  

I would never want an engine, especially a turbo, that could not reliably run LOP as the reasons are too compelling to run ROP as standard practice.

I understand a lot of the issue of the M's not running LOP is with the mags. 

[Awful_Charlie]

I sat with awfulcharlie in his Bravo on a wonderful flight around Switzerland in the fall of 12.  I observed him operating LOP and it ran very nicely that way.  I was really impressed. I will let him pipe in with his operating parameters.

 

I've got GAMIs, but the spread is far from ideal at the moment, about 1GPH, but as someone else pointed out, it varies by throttle setting and altitude.  According to GAMI, it shouldn't be like this, and I will be going back to re-tune them after some more fiddling. (I've just replaced #3 cylinder, as it had a rotten exhaust valve leak, and compression was down to 66/80, the rest are 72-76)

 

Gas over here in France is just over €2 per litre, or over $10 a gallon, so LOP is pretty essential (Switzerland and Germany are even more expensive!).  I normally use a cruise setting of 30"/2200 and lean until the last cylinder (was normally #5, will see if it is the same with the new cylinder) goes just past peak (so 5 or 10 dF LOP on the last to peak, the first to peak are now 80 odd dF LOP) and this normally give me something in the mid 13GPH flow.  I've spent some time calibrating the k-factors in both my JPI and Shadin, so know the FF figures are accurate to within a few % or so. Flying like that would return something like 170-180KTAS at your sort of 120-150 level.

 

Mine will run further LOP, but the drop in power & speed is substantial, and even at my 'just LOP' point, I don't have any problem with CHTs or TITs, say something like 350 and 1500 with the cowl flaps closed.  My 'economy' cruise (for a good tailwind) would be 27/2200 at about 11GPH, and a 'fast' cruise for headwinds 32"/2400 at about 16GPH. I keep all my JPI data and can get you some if you like, but when I do record IAS/TAS it is normally on my PLOG which gets binned after a short time, so that would be harder to correlate.

 

hth

 

Ben

[Awful_Charlie]

Speaking of high altitude flying, I have a question for you oxygen suckers... How mushy are the controls on your planes at those altitudes? I had my F up to 14k once I really didn't like the Cessna 172 feel I felt. Is this true for the turbo versions as well?

The mushiness is just a factor of IAS, so the controls at 120KIAS at FL250 are just as mushy as they are at 1000' and 120KIAS   I know of someone who flies a non turbo TB20 at FL190 frequently with KIAS down in the sub 100 area.  The problem with that in a Bravo is the autopilot is not meant to be used when under a certain speed (it's in the POH supplements which are over in the aircraft) but 110KIAS rings a bell

[aviatoreb]

I've got GAMIs, but the spread is far from ideal at the moment, about 1GPH, but as someone else pointed out, it varies by throttle setting and altitude.  According to GAMI, it shouldn't be like this, and I will be going back to re-tune them after some more fiddling. (I've just replaced #3 cylinder, as it had a rotten exhaust valve leak, and compression was down to 66/80, the rest are 72-76)

 

Ben

 

That's very interesting your engine runs so nicely and smoothly despite a not so impressive spread.

 

BTW - thanks again for the ride!  WOW!

[David Brown]

Gentleman,

 

I have just stumbled in to the Mooney site, and in this thread alone read some pretty alarming things, like running a Turbo 550 at 100ROP etc.

 

I am happy to hang around and help as best I can, but we need to have a mindset of moving past old wives tales and working with data backed facts.

 

To the original poster Danb, I strongly suggest you do two things. First is contact John-Paul Townsend at GAMI on +1 580-436-4833 or by email at john-paul@gami.com and talk to him about getting your injectors sorted.

 

Next thing and equally if not more important is get along to the next APS class that the guys in the USA will be running in ADA OK in March next year. Book in now and you might get the online course thrown in for the interim if you ask John Deakin and mention my name!

 

This will do you wonders. And you can believe me, thats why I now run these class in Australia!

[aviatoreb]

Gentleman,

 

I have just stumbled in to the Mooney site, and in this thread alone read some pretty alarming things, like running a Turbo 550 at 100ROP etc.

 

I am happy to hang around and help as best I can, but we need to have a mindset of moving past old wives tales and working with data backed facts.

 

To the original poster Danb, I strongly suggest you do two things. First is contact John-Paul Townsend at GAMI on +1 580-436-4833 or by email at john-paul@gami.com and talk to him about getting your injectors sorted.

 

Next thing and equally if not more important is get along to the next APS class that the guys in the USA will be running in ADA OK in March next year. Book in now and you might get the online course thrown in for the interim if you ask John Deakin and mention my name!

 

This will do you wonders. And you can believe me, thats why I now run these class in Australia!

 

Welcome David.  Your expertise comments are most welcome.

[KSMooniac]

Welcome David.  Your expertise comments are most welcome.

 

Ditto from me.  Glad you're here, David.  There are a few of us here that fully understand modern engine management, and many that do not.  Your participation will help beat back some ignorance, I hope!  

[Shadrach]

Gentleman,

 

I have just stumbled in to the Mooney site, and in this thread alone read some pretty alarming things, like running a Turbo 550 at 100ROP etc.

 

I am happy to hang around and help as best I can, but we need to have a mindset of moving past old wives tales and working with data backed facts.

 

To the original poster Danb, I strongly suggest you do two things. First is contact John-Paul Townsend at GAMI on +1 580-436-4833 or by email at john-paul@gami.com and talk to him about getting your injectors sorted.

 

Next thing and equally if not more important is get along to the next APS class that the guys in the USA will be running in ADA OK in March next year. Book in now and you might get the online course thrown in for the interim if you ask John Deakin and mention my name!

 

This will do you wonders. And you can believe me, thats why I now run these class in Australia!

Welcome David!  While 100ROP may not be "optimal" (an expression Walt is fond of) for the TIO-540, I don't think it is necessarily alarming if you're running modest power settings (<70%)...