Leaning for take off High DA, float plane

[182-SS]

I was just wondering what other float pilots are doing (your procedure) for leaning for take off on high mountain lakes on a high DA day?
I'm running an IO550 going off of lakes above 5000 ft and sometimes has been around 30 C
I've heard lean for RPM increase on take off run,
leave at your landing setting and add a couple turns richer,
lean out at idle for rpm increase then turn 3 to 4 turns richer.
Thanks for your help

[Lost Lake]

Has the aircraft been properly carburated for higher than normal altitudes. If so, then I wouldn't think there is much to do. Properly richened engines = cooler engines on take off. Proper loads and runway lengths are more important in my mind. Again, this is dependant on carb settings. If you're not getting full rpm, then some leaning may be required.

[182-SS]

Has the aircraft been properly carburated for higher than normal altitudes. If so, then I wouldn't think there is much to do. Properly richened engines = cooler engines on take off. Proper loads and runway lengths are more important in my mind. Again, this is dependant on carb settings. If you're not getting full rpm, then some leaning may be required.

Yes some leaning may be required lol,
IO550 is a injected engine. No carb. But along those lines... I had the fuel flows set
As stated, load is max gross 3100 lbs.
runway is a high mountain lake, plenty long.

Any 185 guys or the likes out there that have some procedures they typically use and care to share?

[MUSICMAAN]

If you want the most of your engine for take off... when your on the lake you are departing from, go to full t/o power and lean till you peak, and then go rich a couple twists, once airborne, I'd richen her up a little more for the climb. If you're operating out of short, high lakes, what I do is before landing, at the same altitude of the lake, go to full t/o power, and lean for full power, then you know where to set the mixture for the take off run from the lake. Watch your cyl temps!

MM

[182-SS]

Thank you very much for the response MUSICMAAN, I have to say I'm quite disappointed that I only got 1 response to my question on a busy web forum, I got the same lack of responses on the CPA forums, I wonder why that is?
Anyways I tried the leaning on take off run, there was plenty of time to do it on the extended take off run at altitude. Very noticeable increase in rpm, improved take off performance, CHT all good, Previously I think i was still much to rich.

[xsbank]

Unless you are approved for reduced-power take-offs, you should not lean for take-off. What does the POH say?
The last (up to 10" depending on the engine) of manifold pressure you are selecting does not add any power, it dumps a sh*t-load of raw fuel in the cylinders to cool them and ensure there is no detonation. The cylinder head temp is not a real measure of temps at the valves and the top of the piston, it is somewhat downstream and not exact. You cannot tell if you are detonating and if you could, the time it took to enrichen the mixture might be too late to prevent damage (melted, very expensive parts). Do you lean on take-off at sea level? Why not?
If this is your engine, lean away as much as you want. If it belongs to me, don't do it. You might want to evaluate where you are operating out of and examine whether you are using the correct aircraft.

[Colonel Sanders]

above 5000 ft and sometimes has been around 30 C

My God, man, you absolutely must lean for takeoff with that
density altitude! With a constant-speed prop, leaning for max
RPM probably isn't going to work very well. You need to know
what your mixture setting should be, before takeoff.

The way I would do it is find out what mixture setting gives you
best airspeed in flight under those conditions, and that's going
to be around 50F to 100F rich of peak - best power. Push the
mixture in another half-inch or so for cooling with a reasonably
rich mixture.

The above is true for both fuel-injected and carbureted engines
with a conventional mixture control - I'm not talking about
pressure carbs on 1950's vintage aircraft.

I have never heard of anyone at high density altitude, detonating
or pre-igniting a naturally aspirated, low compression aviation engine
running 100LL, no matter how badly they mismanaged the mixture
control. There just isn't enough air to make much power, and
the 100LL is just swimming in tetraethyl lead.

[182-SS]

Unless you are approved for reduced-power take-offs, you should not lean for take-off. What does the POH say?
The last (up to 10" depending on the engine) of manifold pressure you are selecting does not add any power, it dumps a sh*t-load of raw fuel in the cylinders to cool them and ensure there is no detonation. The cylinder head temp is not a real measure of temps at the valves and the top of the piston, it is somewhat downstream and not exact. You cannot tell if you are detonating and if you could, the time it took to enrichen the mixture might be too late to prevent damage (melted, very expensive parts). Do you lean on take-off at sea level? Why not?
If this is your engine, lean away as much as you want. If it belongs to me, don't do it. You might want to evaluate where you are operating out of and examine whether you are using the correct aircraft.

What forum am I in right now?

Leaning at sea level? Why not?
Reduced power take offs? You should not lean for take off?

I’m pretty sure I’m in the bush pilot forum, which would mean people commenting know what I’m talking about, such as MUSICMAAN, he actually gave response that answered the question.

Its common knowledge for mountain flyers that it is a necessity to lean for take off when at a high altitude strip or lake especially when hot out making the density altitude over 8000ft, the difference in power is phenomenal when done properly.
I just was hoping to glean some knowledge off some bush pilots that operate out of some high strips or lakes. Just seeing their procedure.
That’s fine that you would not lean for this situation, however you may find yourself in some difficulty ( or dead) if you don’t, although it sounds like you wouldn’t be flying in the mountains in the first place with the comment to me regarding re thinking where I am operating out of. Or the correct aircraft, I'm running a Seaplanes West / Airplains IO550 Cessna 182 on Aerocet 3500L floats. It will outperform a stock 185 (no offence 185 guys, I grew up on 185's still miss the johnson bar flaps). I'm not operating out of puddles that would require a 300hp carbon cub.


Colonel Sanders,
I’ve been leaning for take off, just as the old saying goes there are many ways to skin a cat, I just wanted to see what other guys procedures were.
Your suggestion is basically what I was doing before however I think I was giving it a couple twists too much and ended up a bit on the rich side for best power.
And you're right as well regarding xsbank, there is no worry about detonation. Thanks for the comment, I believe you and musicmaan know what your talking about.