82 inch prop install on M5 210C

Seaplane Maule · Post by **Seaplane Maule** » Tue Jul 24, 2012 5:15 pm

I got the C203 80" approved a few years back on my M5 210C using the XP Mods STC for the installation of prop and engine in a Cessna 170 as the basis for compatibility.They had done the vibration analysis on the IO360 D/C203 prop. To prove the prop was okay clearance wise I had to measure the prop clearance with a flat tire and bottomed out oleo spring....Float clearance was no problem..This mod makes a huge difference in performance. Since then I have installed M7 wings 33'8"span and swapped my EDO 2440 floats for Wipline 2350A amphibs(still have a 785 lb usefull load on floats with impressive performance for an amhib)

maules.com · Post by **maules.com** » Tue Jul 24, 2012 10:23 pm

Prop clearance is tail up in wheel landing configueration, full load, one main tyre flat = 9".
The 81" prop gives this clearance on 7.00x6 tyres.
The 86" prop misses by half inch on 8.50x6 tyres.(only 8.5")

pancake · Post by **pancake** » Wed Jul 25, 2012 12:44 am

Wow,you guys got a lot of info. The C203 seems to be the most popular and effective choice but the specs say it works with an engine with one sixth and one 4.5 damper but my "D" engine has two sixth order dampers, will it still work? Ust to throw this out there, mine runs rough at low rpm's but people have told me that is a factor of this engine. Any comments on that?

aero101 · Post by **aero101** » Wed Jul 25, 2012 9:19 am

The prop works well on the "D" model engine, no problem there. I always have prop dynamically balanced upon installation as well just for good measure.

Seaplane Maule · Post by **Seaplane Maule** » Wed Jul 25, 2012 12:33 pm

Try leaning out at low rpm...if fuel flow is set right it runs a bit rich at low rpm...

pancake · Post by **pancake** » Thu Jul 26, 2012 10:43 am

Great! I will start my search again. Where do I find the info on what prop works with what engine? Your earlier response with all he different types and combos was great. I found early on that leaning it out on the ground works good, it not only smooths it out a little but mostly it keeps from fouling spark plugs.

iceman · Post by **iceman** » Sat Jul 28, 2012 4:19 pm

learned early on to lean a bit on taxi.. M4 210C... keeps plugs from fouling and runs a bit smoother... but it's nature of the beast I've been told that it runs somewhat rough on the ground and smooths out nicely adding some power...DOn't know what numbers are on my prop I'll have to look... but it's the same McCauley as used on the Hawk XP..

iceman · Post by **iceman** » Mon Aug 06, 2012 9:28 pm

checked mine this week... It's a 78" prop that went on the 172 XP... It only has about 300 hrs since new and Now I';m wondering if any performance increase would be worth the trouble and expense of going to 82 inches.. with my 29 11 10's I'm only getting 120 MPH cruise now but I do get off the ground much sooner.. certainly would be nice to get back to 130/135 where it was with my 800's...

iceman · Post by **iceman** » Tue Aug 07, 2012 2:49 pm

checked my paperwork again and the McCauley handbook that came with the prop... I have a -2 after the model # so I gather it is actually 76"... checked on pricing for the c203 at 80" and at over 8,000 bucks I figure I'll just keep plugging along at 120....and buy a lotttery ticket now and then but then If I actually win I won't be flying a M4 any more...

maules.com · Post by **maules.com** » Tue Aug 07, 2012 3:06 pm

Iceman, drag is drag and round things are the worst.
Even if you got a better prop, the difference would show in takeoff and climb rather than speed. Your 10 to 14mph loss is to be expected.
At Cub speeds, drag increase is there with big tyres, but not as much, naturally.

aero101 · Post by **aero101** » Tue Aug 07, 2012 6:06 pm

Originally the C203 comes at 90" or -0, so that makes a -2 an 88" which is probably what it was originally on something else like maybe a C180. As Jeremy said long prop will actually considerably reduce glide efficiency, and will not help airspeed at due to added drag. $8K for a new one sounds awful pricey to me, last one I bought for customer brand new was a couple thousand cheaper then that, would be worth doing some shopping? Or if you have a good hub, you can buy just blades as I did last one I purchased. If I remember right, I had less then $4K total including overhaul with new blades and a used hub? There is no book available listing props, it takes research of Prop TCDS's or various STC's for those approved for specific engine and specific length combinations. For both the Franklin and the Continental there's not alot of choices....

51598Rob · Post by **51598Rob** » Fri Aug 10, 2012 6:34 am

I have an 82" Mc on a M5-210. Performance is great! My Maule climbs like it's afraid of the ground. Speed... I have 31's and went from seeing 120 knots with 8:50's to 105 knots. Don't think it's going to matter what prop you have if the tires are big. As for glide, my opinion is that gliders need high ratios, short field airplanes need brakes. I like that when I pull power, my airplane looks for the ground (short wings,big prop,big tires). We have big engines and props to go the other way, and big tires to make more open patches into runways.

Mountain Doctor · Post by **Mountain Doctor** » Fri Aug 10, 2012 10:25 am

51598Rob wrote:I have an 82" Mc on a M5-210. Performance is great! My Maule climbs like it's afraid of the ground. Speed... I have 31's and went from seeing 120 knots with 8:50's to 105 knots. Don't think it's going to matter what prop you have if the tires are big. As for glide, my opinion is that gliders need high ratios, short field airplanes need brakes. I like that when I pull power, my airplane looks for the ground (short wings,big prop,big tires). We have big engines and props to go the other way, and big tires to make more open patches into runways.

A little different way of looking at it than usual but a good argument.

Where is Eastern Oregon are you? I'm in Tri-Cities, Washington.

m5210guy · Post by **m5210guy** » Sat Aug 11, 2012 11:06 am

How did you get approval for the 82" prop on your M5-210 .Is there an STC for that prop ?

51598Rob · Post by **51598Rob** » Sat Aug 11, 2012 6:47 pm

Location is near Imbler. Minam Lodge/Reds Horse Ranch is out my back door.
My prop has a 337 that was done in AK.

82 inch prop install on M5 210C

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