Time limits for takeoff power.

[Jetpilot86]

I’ve got my first mountain airport launch in a few weeks. 20V is the airport and the MEA’s are at 14000 as I head SSW to FLG. 
 

What I’ve found with my Bravo is that if I’m not at 130k before setting Climb Power, the #6 CHT will break 400°. To do that, I’m climbing at 300fpm with OAT at ISA+20. I’ve got new BeeGee baffling, 29gph on Takeoff and temps in the 360°’s at takeoff power in the white arc. 
 

My question is how long do y’all think I can run at ToP and Vy to meet the Departure Procedure?  It’s a 2600’ climb in tighter quarters than usual. I’ll have one chance to take a look at this when I move my Bravo from CFO to 20V next week. I’m pretty sure I won’t meet the DP accelerating to 130k @ 200fpm in the valley. 

[TheAv8r]

Lycoming or Continental engine? Lycoming the cylinders can get up to 440 CHT, not that that's good for the engine, but that's where Lycoming identified as the danger zone. Safety comes first, best engine practices come 2nd, if to fly the departure procedure correctly requires some hotter cylinder temperatures, it is what it is. You can run the math to figure out what your climb rate needs to be for your expected speed to match that 370 or 500 ft/nm and verify against the POH the aircraft can do it. If you hit 400 but stay there, that's not the end of the world IMO.

[Jetpilot86]

Lycoming TIO-540 AF1B

[midlifeflyer]

I think temperatures are always an issue but unless there is a limitation on power - which some aircraft have - I don't see a reason other than temperatures  to reduce the climb profile until getting to the safe altitude. OTOH, since the weather is likely to be clear and 100, you can always opt to do something other than the published ODP.

[LANCECASPER]

2 hours ago, Jetpilot86 said:

I’ve got my first mountain airport launch in a few weeks. 20V is the airport and the MEA’s are at 14000 as I head SSW to FLG. 
 

What I’ve found with my Bravo is that if I’m not at 130k before setting Climb Power, the #6 CHT will break 400°. To do that, I’m climbing at 300fpm with OAT at ISA+20. I’ve got new BeeGee baffling, 29gph on Takeoff and temps in the 360°’s at takeoff power in the white arc. 
 

My question is how long do y’all think I can run at ToP and Vy to meet the Departure Procedure?  It’s a 2600’ climb in tighter quarters than usual. I’ll have one chance to take a look at this when I move my Bravo from CFO to 20V next week. I’m pretty sure I won’t meet the DP accelerating to 130k @ 200fpm in the valley. 

Are your cowl flaps full open and rigged properly? Have you swapped probes with the cylinder next to it to see if you’re getting a good reading - maybe defective probe? Have you used the flashlight test to see if light (or air) is getting past the baffles?

If your cowl flaps are set up right and the probe is correct and your baffles aren’t letting air over the top, then something is going on with that cylinder. If that’s the case I’d rather not be over mountainous terrain in a single engine airplane trying to figure it out.

[Jetpilot86]

26 minutes ago, LANCECASPER said:

Are your cowl flaps full open and rigged properly? Have you swapped probes with the cylinder next to it to see if you’re getting a good reading - maybe defective probe? Have you used the flashlight test to see if light (or air) is getting past the baffles?

If your cowl flaps are set up right and the probe is correct and your baffles aren’t letting air over the top, then something is going on with that cylinder. If that’s the case I’d rather not be over mountainous terrain in a single engine airplane trying to figure it out.

All of the above, by Maxwell and others. Did the probe swap a few weeks ago. No change. GAMI lean test(manual) has them all within .5 gal. 
The only thing I can’t check is if air pressure is causing the left side to trail more from when it was jamming 3” open when the right side was closed. The torque had actually bent that cowl flap and the bottom mount for the actuator on the door. The door has been repaired and rerigged at Maxwell’s. 
I’m also being told to not be concerned for another 100 hours or so since I’m still a few hours shy of 100 SFOH. 

A lot of people, smarter than I are baffled by this. 
 

Attached are a couple of CHT graphs. One good, after I figured out to accelerate to 130k before setting 34/24 & one before. CHT #5 is the OEM CHT, and in the gauge runs about 360° most of the time vs the spark plug thermocouple used on the G2. 

[jetdriven]

For best climb rate, don’t reduce the prop Rpm , all it does is take away performance. It actually increases cylinder pressure and then you have even more of a heating problem. There isn’t really a takeoff limitation on this powerplant at all if I recall, but you may need to limit manifold pressure and raise the airspeed up in order to keep it cool enough to be acceptable. And 400 is not a limitation it is a arbitrary limitation set forth for continuous operation by a large percentage of pilots, but if it comes to reducing power and keeping the CT below 400 or leaving it all the way forward and clearing the mountainous terrain,  you can bet which one is easier on the engine. You might consider climbing a bunch of circles over the airport before setting off on your airway because although you can turbocharge the engine, you can’t turbocharge the prop or the wing.

[Fritz1]

I typically climb at 34" 2400, flow 23.5, 120 kt, max CHT on #4 or #6 390 F, 600 fpm up to 18,000 ft, the Bravo engine is very sensitive to leaking baffles, make sure they are pressed snug against the cowl all around, check with light, seal every nook and cranny with RTV, check baffles between cylinders, the smallest loss of ram air makes a difference, check if the # oil injector is flowing freely, take oil line off, take valve cover off, flush with solvent, blow through with compressed air from both sides, bore scope cylinder, something may be going on

[LANCECASPER]

How is your oil consumption?  With less than 100 SFOH did that cylinder break in? Could it be glazed ?

[FoxMike]

I assume if you are basing at RGL and your concern is the occasional IFR departure.  I have had my Bravo into RGL a number of times but never have had to depart IFR.  If the weather is nice tomorrow you should fly up for an airport familiarization.  It is tight around the immediate vicinity but after a good look around I think you will get comfortable with the terrain.  A few years ago I did an IFR departure out of Rifle.  Engine gets hot especially with above standard conditions.  I normally climb at 120Kts.  If your cylinders get above 400F things will only be that way for only a few minutes.  I operate my engine very conservatively so unless the clouds force me to do a departure procedure I climb out VFR and call for my clearance enroute.  Hot engines wear out faster but they run Ok while in service.  Something to keep in mind Mooney, when they certified the Bravo only had to provide cooling for standard temp. plus 40F.  Often in this part of the country we are operating at plus 50F.  One genuine advantage of the Bravo is the wet head.  It does provide quite a bit relief to the exhaust valve. Good luck in operating out RGL.  The Bravo is one of only a few single engine airplanes that operates well in the Rockies.  

[Jetpilot86]

9 hours ago, FoxMike said:

I assume if you are basing at RGL and your concern is the occasional IFR departure.  I have had my Bravo into RGL a number of times but never have had to depart IFR.  If the weather is nice tomorrow you should fly up for an airport familiarization.  It is tight around the immediate vicinity but after a good look around I think you will get comfortable with the terrain.  A few years ago I did an IFR departure out of Rifle.  Engine gets hot especially with above standard conditions.  I normally climb at 120Kts.  If your cylinders get above 400F things will only be that way for only a few minutes.  I operate my engine very conservatively so unless the clouds force me to do a departure procedure I climb out VFR and call for my clearance enroute.  Hot engines wear out faster but they run Ok while in service.  Something to keep in mind Mooney, when they certified the Bravo only had to provide cooling for standard temp. plus 40F.  Often in this part of the country we are operating at plus 50F.  One genuine advantage of the Bravo is the wet head.  It does provide quite a bit relief to the exhaust valve. Good luck in operating out RGL.  The Bravo is one of only a few single engine airplanes that operates well in the Rockies.  

It’s Kremmling. When I did my insurance checkout in an APA based Bravo last year I specifically hit Kremmling, Eagle Rifle, Grand Junction & Hayden. Someone seemed to be playing games on the radio at Rifle saying the airport was closed when there were no notams. Anyway, that Bravo seemed to have better climb rates than I see in mine, but it was early November as well. 
 

I’ll be taking note when I leave CFO next week to see how the temps are for an extended Vy climb which I haven’t done in this plane yet. 

[BlueSky247]

Lurker to these parts just wanted to second the wet head benefits but also express my dismay that a turbo 540 has challenges in this area. Surely OP isn't doing these takeoffs at max weight?

[Jetpilot86]

14 hours ago, LANCECASPER said:

How is your oil consumption?  With less than 100 SFOH did that cylinder break in? Could it be glazed ?

1qt over 25 hours. I put 8 in at the last change + the camguard. Flew it hard the first 25 hours, Run 70% cruise now, much above that and #6 is over 380° at 1/2 CF. 

[Jetpilot86]

22 minutes ago, BlueSky247 said:

Lurker to these parts just wanted to second the wet head benefits but also express my dismay that a turbo 540 has challenges in this area. Surely OP isn't doing these takeoffs at max weight?

Yes, nearly every takeoff is at MGTW. When I launch, it’s usually for 800+ NM

[LANCECASPER]

7 hours ago, Jetpilot86 said:

1qt over 25 hours. I put 8 in at the last change + the camguard. Flew it hard the first 25 hours, Run 70% cruise now, much above that and #6 is over 380° at 1/2 CF. 

Ok, well in that case I would go back and look at @Fritz1 's last post about checking and RTV-ing every nook and cranny, 
 


Then check out the intercylinder baffles and make sure they are there, and connected since it's a newly re-installed engine.

[FoxMike]

I had a couple of thoughts you might find useful.  When you start operating 14-18K altitudes you may notice your oil pressure getting down near the yellow.  A turn two on the oil pressure regulator should solve that problem.  The other thought is where you will get O2.  The FBO at RLG may have some but a friend who used to hangar up there brought his from his shop.  Running over to EGE would be a fun flight but the O2 cost would likely be enormous.  From what you said about your flight profile you will be using a fair amount.  I have been hearing some horror stories about cost of O2.  You might consider making up an O2 adapter so you can do it yourself.

[PilotX]

O2D2 is a must if you plan to use O2 a lot. Swing by and get topped off at KBJC at  @Warren’s

[Jetpilot86]

11 hours ago, FoxMike said:

I had a couple of thoughts you might find useful.  When you start operating 14-18K altitudes you may notice your oil pressure getting down near the yellow.  A turn two on the oil pressure regulator should solve that problem.  The other thought is where you will get O2.  The FBO at RLG may have some but a friend who used to hangar up there brought his from his shop.  Running over to EGE would be a fun flight but the O2 cost would likely be enormous.  From what you said about your flight profile you will be using a fair amount.  I have been hearing some horror stories about cost of O2.  You might consider making up an O2 adapter so you can do it yourself.

The O2 at CFO is $85, what is it at BJC?  Solo, in the upper teens, I’ve gotten 50 hours TT out of my bottle with a manual regulator and the reservoir cannula. While either the O2D2 or the Precise Flight version are on the list, at my current rate of consumption, still not worth the extra expense, yet. Once I get through Summer Vacation flying season with the Copilot, I may reevaluate. I’m also still working on a non shared hangar so the “collection” of goodies is on hold as well. 
 

Haven’t seen the Oil Pressure issue yet. 

[Jetpilot86]

4 hours ago, PilotX said:

O2D2 is a must if you plan to use O2 a lot. Swing by and get topped off at KBJC at  @Warren’s

How much for O2 at BJC?

[Niko182]

2 hours ago, Jetpilot86 said:

How much for O2 at BJC?

I pay 30 bucks to fill my portable tank at Legacy

Also , why not simply tell center you're VFR on top when you pick up your IFR clearance on the ground so you don't have to do the ODP while still being on an IFR flight plan? I've done that a couple time flying for work, where they prefer we be on an IFR flight plan. Simply get your clearance on the ground, request VFR on top while you're holding short of the runway, and they'll ask you if you are in VFR on top conditions, and you simply tell them you are. No required climb rate to meet, except the 500FPM.

Edited July 7 by Niko182

[LANCECASPER]

3 hours ago, Niko182 said:

I pay 30 bucks to fill my portable tank at Legacy

Also , why not simply tell center you're VFR on top when you pick up your IFR clearance on the ground so you don't have to do the ODP while still being on an IFR flight plan? I've done that a couple time flying for work, where they prefer we be on an IFR flight plan. Simply get your clearance on the ground, request VFR on top while you're holding short of the runway, and they'll ask you if you are in VFR on top conditions, and you simply tell them you are. No required climb rate to meet, except the 500FPM.

Wouldn't they see that you are doing 0 knots groundspeed?

[Niko182]

1 minute ago, LANCECASPER said:

Wouldn't they see that you are doing 0 knots groundspeed?

They give you a vfr on top clearance so you just handle your own terrain clearance on takeoff. I’ve gotten VFR on top clearances while on the ground. You’re not tricking them. They know you aren’t flying. Just allows you to handle your own obstacle clearances while still being on a full IFR flight plan.

[Fly Boomer]

On 7/5/2024 at 10:07 AM, Jetpilot86 said:

I’m pretty sure I won’t meet the DP accelerating to 130k @ 200fpm in the valley. 

How about VCOA?

[Jetpilot86]

Just FYI, I know all the ways around departing VFR, I’m just sorting out how to depart IFR and meet the requirements while not tearing up our delicate flower of an engine.