I recently converted my 182 to a Northpoint XP470 and am still trying to figure power settings and fuel burn for the different altitudes. In all my research before, I ran across a comment that said the % of power and fuel burn was really close to a certain model 210 but I can't seem to find that again. Anyone know what it is? Or is there a chart for the PPonk someone can post? I've searched but haven't been able to find anything other than a few comments here and there. One day Ill get around to installing a fuel flow transducer and upgrading the JPI to a model that can calculate % of HP but it wont be real soon. At the very least, what settings are you running for 65% or 75% at 3000,6000,9000 & 12,000? Thanks

Just went through the same thing.
XP470 approximate settings are listed here. http://northpointaviation.net/northpoint-xp470/
210 manual is here. https://jasonblair.net/wp-content/uploa ... Manual.pdf

But frankly I still haven’t worked out real solid settings. On floats we seldom go high. Down low, the advice to find where the rpm is smoothest, then set MP and mixture to make happy cylinders doesn’t help because on this engine I cannot find any vibration difference across the rpm range. I am not calling it turbine smooth but no detectable vibration change.

I am currently working to get my cowl flaps adjusted further open. These hot OATs make it difficult to run at 75% power. The P model book says 13 minus 1, plus 3 degrees for cowl opening. Looking around the ramp, I see most cowl flaps much further open. I plan to have them opened to the full 16 degrees next time the cowl is off.

So currently running 23” 2450 for climb, 22 squared for slow cruising and 23 squared fast cruise. On floats the speed change isn’t much between 22 and 23 squared.

I asked this question to Knopp some years ago, since I had no power chart for my Pponk 520. They sent me a copy of an IO 520 power chart from a Cessna 206 manual and said it would be pretty close. I've kept a copy in the airplane and occasionally refer to it. For what it's worth, I typically cruise at 20 in and 2300, which is about 52% power at 2500 ft according to the 206 chart. I have a 58 180A and I usually don't go that far on any particular trip, so speed is not that important.

I don’t have any charts, but some other pponk pilots have weighed in here:

https://backcountrypilot.org/forum/cess ... gine-22536

My experience aligns pretty closely with what these folks have found.

Thanks for the thoughts and links to more info. Seems like I keep averaging 15+gph instead of the 12-13 I was expecting from reading other peoples experience. Maybe they are looking at the fuel flow indication while at that power setting and not including the takeoff and climb out. Guess I need to go on a nice long cross country to see how it works out on legs longer than a couple hours. How far ROP are you guys running? I've had to work on tightening up the baffling a bit as the #2 cylinder was running hotter than 380 unless I ran it a bit rich. Seems to be decent now but I still cant close the cowl flaps all the way in cruise. Surefly might be playing into that some too I guess.

7GC wrote: For what it's worth, I typically cruise at 20 in and 2300, which is about 52% power at 2500 ft according to the 206 chart.

What are you seeing for fuel burn at that setting?

Scolopax wrote:My experience aligns pretty closely with what these folks have found

How many hours do you have on yours now Jake?

19 years on our Pponk, about 1500 hours. C-180; 86" Mac 401, floats, skis.

Down low, local flying:
2450/22" 14GPH

Typical cruise flight, 7-8000'
2450/full throttle, (but backed out a touch to even out fuel distribution)
12.5-13.5 GPH

High cruise, was up at 11,500' the other day to clear some weather(on floats...Pponk's rock):
Same settings as above, 11 GPH.

To keep the CHT's below 350, the cowl flaps are basically always open down low.

We flight plan for 15, works well with T/O and climb fuel.

One final note for those operating at low RPM's. This service bulletin is often overlooked. It's worth considering.

http://www.tcmlink.com/pdf2/CSB09-11A.pdf

About 12 gph at 20 in/2300 rpm. 50 rich of peak. Hottest CHT usually 345-355, depending on OAT.

One final note for those operating at low RPM's. This service bulletin is often overlooked. It's worth considering.

http://www.tcmlink.com/pdf2/CSB09-11A.pdf

Aqua, thanks for posting that. I usually am at 20/2300 with an electronic tach but might increase rpm's a little.

This thread highlights one of the problems with so many of our back country aircraft these days: The results of modifications of our aircraft.

Many of the engine mods in particular (mine is a Lycoming O-360 in place of a Continental GO-300, as an example) provide as part of the STC a decent power chart.

You can often find something close enough from the engine manufacturer, but in some cases, for example the Ponked O-470s, you may just have to make your own power chart from experience.

I'm lazy, though, and I find that, like me, many pilots adopt a couple of power settings that they favor, and use regularly. Figuring out the information you need is easier for that kind of scenario than it would be for developing a full out power chart for an engine.

I will also testify that one of the best things you can put in your airplane is a fuel flow computer. After I parked a 185 on a mountain side, our aircraft folks were prepping a replacement airplane for me to use till they could replace that one. They asked me what equipment I NEEDED in that replacement airplane. My answer was simple:

1) BAS Harness system
2) GPS
3) Fuel flow computer.

Particularly on aircraft with large fuel capacity, it's really, really important to know fairly precisely how much gas you have aboard at any point in time. A fuel computer will make that task super easy.

Seriously, don't even slow down....just install one, believe me, you'll never look back. And, that device will make developing the data that you seek SOOOOO much easier.

MTV

chedrick wrote:How many hours do you have on yours now Jake?

At about 125 hours since the fresh engine. It's been a busy year in my wagon

I typically run 2350 at 19"-21" on cross country flights. Usually see 12-13 gph at 135 knots using these settings. Always at 6000+ feet.

During survey work, we run 2000 rpm and between 18-20 inches MP. <8 gph at 100 knots.

I have posted on this subject matter previously in other threads. I have Texas Skyways O520 UTS equipped 1958 C180. I have a Sportsman STOL kit and Snider speed kit. Plane is rigged reasonably well.

Take off - Full throttle/2700 RPM - Mixture Rich other than possibly adjusted for DA.
Climb - WOT/2600-2700 RPM - Mixture adjusted to EGT < 1275 on the leanest cylinder up to altitude. Cruise climb 120 mph indicated.

Cruise - Unless I am trying to show off and burn a lot of fuel - it makes no sense to run it hard down low < 4K. I run it 20/2300 burning 12.5 gph - roughly 65% power - I see 135 KTAS. It is more efficient between 8-11K. I run it WOT/2400 RPM - usually the leanest cylinder at peak EGT. Keeps the CHTs < 370 even in the summer and it will true out at 146-148 knots burning 12.8-13.5. I have a EDM 900 and aim for 60% power. I can pick up a few knots flying it between 4-7K WOT/2400 RPM but need to burn 14-15 gph. Carson's number definitely applies to the Skywagon although i would say it is most efficient indicating 150 mph. If you want to run it super fast - WOT/2600 burning 20 gph - I'll see 155 knots - 180 mph indicated. On really smooth days with no bumps I will run it like this just because I believe in the Italian tune up and it is fun.



Josh

180Marty wrote:

One final note for those operating at low RPM's. This service bulletin is often overlooked. It's worth considering.

http://www.tcmlink.com/pdf2/CSB09-11A.pdf

Aqua, thanks for posting that. I usually am at 20/2300 with an electronic tach but might increase rpm's a little.

Good info in that SB, but not sure it applies to PPonks. Even most models of 520s that we run in our backcountry aircraft aren't affected by this SB. I am curious if they researched and found that certain models were more susceptible to damage from operating low or why they only picked out certain model.

Dog, I wish I could get the speed you do at the same power setting. I run 20 in, 2300 rpm at about 2000 ft and indicate about 130 mph. I have Horton kit and apparently a "drag kit" - 29 Bushwheels and Baby Bushwheel.

mtv wrote:Seriously, don't even slow down....just install one, believe me, you'll never look back. And, that device will make developing the data that you seek SOOOOO much easier.
MTV

Note taken; it is on the short list and will happen this winter if not sooner. Thanks!

Scolopax wrote:At about 125 hours since the fresh engine. It's been a busy year in my wagon

Man you have been busy! I'm jealous!

A lot more great info from everyone else. Thanks!

A1Skinner wrote:

180Marty wrote:

One final note for those operating at low RPM's. This service bulletin is often overlooked. It's worth considering.

http://www.tcmlink.com/pdf2/CSB09-11A.pdf

Aqua, thanks for posting that. I usually am at 20/2300 with an electronic tach but might increase rpm's a little.

Good info in that SB, but not sure it applies to PPonks. Even most models of 520s that we run in our backcountry aircraft aren't affected by this SB. I am curious if they researched and found that certain models were more susceptible to damage from operating low or why they only picked out certain model.

I believe that SB only applies to the “permold” style engines, not the “sandcast” that the 180/185/206/207 use. I’m not 100% certain, but I think the easy way to tell the difference is the location of the alternator; back of engine is sandcast, front of engine is permold.

Chris


Sent from my iPad using Tapatalk