A fuel flow gauge and multi probe EGT have been the best thing for my 182 and like all pilots a source is probably too much over thinking.
I was flying around Tok, ak last night and the OAT was up around 85. I pretty much never fly in temps like that. I seem to be running the pponk at 2300rpm 20mp and lean for 13gph lean of peak. In this hot weather the CHT are getting up to 400 . I have to run rich of peak a fair amount to get the temps cool enough. Up around 16gph yesterday. I'm sure if it was hotter I could run even more fuel through it but I'm not sure I would want to fly around at 16+ gph all day.
How does everyone do it in hot climates? 85 degrees is pretty hot but not uncommon most places. So what's your OAT limit for flying a big continental or any other airplane around and still being able to maintain good CHT.
Maybe I just need to yank these fancy engine analyzers out and go back to having my head in the sand.

I'm a little surprised 13 gph is LOP at that power setting. I've got an IO-520D, so not exactly the same engine, but same displacement and at 22 MAP my peak EGT is around 13 gph. At a lower MAP like 20", my peak is somewhere around 12-12.5 gph. If I set your FF/MAP/RPM setting, my engine would be right in the heart of peak power (and CHT) on the mixture curve. My engine runs quite cool once LOP (320-330), but I don't know that is much of a comparison given other factors that can affect CHT.

I split my time between No. Cal and Arizona. I have the problem in both locations.

I have the Pponk in my 182, and had a hell of a time with #4 & #5 getting to 400+ creating a lot of concern to me. It seemed to happen quickly if I reduced MAP during climb out.

I now keep full open throttle until I level out for cruise. Full throttle keeps some extra fuel in the flow and seems to keep the cylinders below 380 in climb. at altitude, I let it stabilize for a few minutes and then reduce MAP to 22" RPM to 2300. I then let it stabilize for a few more minutes and begin leaning.

I agree that the information available from the JPI engine analyzer is almost overload and I have not been able lean it consistently with the JPI lean function. So I just go back to the method I learned when I started flying. I pull it back to 15 gph and then slowly lean until I get drop in rpm. 1/2 turn to rich and I tend to end up at 11.7 - 12.5 gph and all CHT's 330-365.

I don't do anything but long x-county if air temps are above 80 F. Getting to altitude (i.e,, cooler temps) and the above procedure make me and the engine happy campers.

Every engine has a sweet spot, and this is what is working for me.

PAMR MX wrote:A fuel flow gauge and multi probe EGT have been the best thing for my 182 and like all pilots a source is probably too much over thinking.
I was flying around Tok, ak last night and the OAT was up around 85. I pretty much never fly in temps like that. I seem to be running the pponk at 2300rpm 20mp and lean for 13gph lean of peak. In this hot weather the CHT are getting up to 400 . I have to run rich of peak a fair amount to get the temps cool enough. Up around 16gph yesterday. I'm sure if it was hotter I could run even more fuel through it but I'm not sure I would want to fly around at 16+ gph all day.
How does everyone do it in hot climates? 85 degrees is pretty hot but not uncommon most places. So what's your OAT limit for flying a big continental or any other airplane around and still being able to maintain good CHT.
Maybe I just need to yank these fancy engine analyzers out and go back to having my head in the sand.

DA?

We are probably in our last week of *lows* below 80 ˚ until mid September, in fact it is 85˚ now at 11PM. In a week or two more we will go for weeks without even getting below 100˚. Don't know what we'd do if we had an OAT limit? The analyzer is your friend, before analyzers, everyone thought mid time tops in a big bore Continental were the norm, now we know it doesn't have to be that way

I try and cap my CHT's at 380˚, and do what it takes to abide by that. I also make 400˚ my absolute limit, regardless of what the factory says. I will pull cow flaps, carb heat, slow up the rpm, or speed up the airplane, what ever it takes. Having said that, I rarely need to do much fussing unless it is well above 100˚.

I too am surprised to hear your burning as much as 13 gph and still LOP, at those settings. I can make it burn 13gph, but it'll be right at peak, and for me, that's not the greatest place to be. I also don't have any interest in running a Pponk LOP. Gas is cheaper, and more convenient than replacing tops. A little Marvel will keep the lead at bay if that is the push for running LOP. IO's? sure, give me LOP, clean plugs and great mileage all day long.

Absolutely every Pponk I can think of off the top of my head, was delivered with the carb set too lean (even after the carb mod), but that shoudn't affect your cruise, just your climb. Until we revisited my carb, I would have to pull a little carb heat right after breaking ground to keep my temps at bay in an extended climb. But again, climb, not steady cruise.

I'm guessing your at a couple hundred feet to start so shooting from the hip at those temps I'd probably be burning 14" +/- a few tenths to keep it ~380˚. 16gph would be plenty slobbery at 2300&20"

Take care, Rob