82 inch prop install on M5 210C

pancake · Post by **pancake** » Sat Jul 14, 2012 12:01 pm

i have an M5 210 with a factory 74 inch prop, i have obtained an 82 inch prop to put on. while investigating the install i found that when i remove my existing prop and it is the horizontal position in relation to the ground, when i went to put the new one on, the locating dowels are in a different position which put it at 45 degree angle instead of horizontal. has anyone done this? is there any concern of the prop being out of sync with the crankshaft or the counterweights on the crank?

iceman · Post by **iceman** » Sat Jul 14, 2012 6:00 pm

hmmmmm don't know but I'd be interrested to hear... also interested in your performance changes...I have the mccauley prop that went on the Hawk XP with our engine on my M4...

aero101 · Post by **aero101** » Sat Jul 14, 2012 6:08 pm

What make / model prop are you installing? There is a very limited number of props certified on the IO360 Conti, if you install something not certified for that engine you could certainly mess with crank as well as actually break a blade in flight, which would probably be deadly... Just because a prop fits flange bolt pattern does not make it compatable with any engine having that flange! I suggest you talk to licensed A&P / IA who can do a little research of tcds of your prop. You also need either an STC of which I've only heard of one for the early conti, or a field approval for the XP Prop which I've done at 82" which works nicely.

pancake · Post by **pancake** » Wed Jul 18, 2012 12:55 am

thanks for the replies. the prop i have came off a Cessna 180 but do not know if that is the original plane it was on. the one i have is a McCauley 2A34C66-NP if that means anything????

aero101 · Post by **aero101** » Wed Jul 18, 2012 3:11 pm

That prop is certified for the Conti IO470 only with 4ea 4th order dampeners, not approved on the IO 360 per prop TCDS-

D2A34C66
90AT Continental 0-470
and I0-470 Series
(up to 260 hp.
@2625 r.p.m.)
Four 6th order dampeners
88" - 76"

2A34C203 90DCA Continental I0-360
Series (up to 210
hp. @2800 r.p.m.)
One 6th and one
4.5 order 80"to 74"

2A34C209
or
2A34C210
78CCA Continental I0-360
Series (up to 210
hp. @2800 r.p.m.)
Two 6th order,
or one 4.5 and
one 6th order
78" to 72"

Above are approved for this engine with preferred and longest prop being the C203 at 80". I've done this prop on a couple of field approvals and works like a banshee on floats. It is also same prop used on the Cessna XP (80")and also the STC that installs IO360 on a Stinson (82")

pancake · Post by **pancake** » Wed Jul 18, 2012 9:44 pm

wow, thanks for all that info, i really appreciate your time. any ideas where to find these models? i have it on 31's in the summer which is ok but have it on schneider penetration skiis in winter and always seem to be fully loaded. the skiis are horrible as far as drag with the tires sticking through and that is really my need for the longer prop. well, not to mention the fun factor

aero101 · Post by **aero101** » Thu Jul 19, 2012 9:05 am

The C203 prop is also used on some earlier C 180's and C182's...

pancake · Post by **pancake** » Thu Jul 19, 2012 9:32 am

having done this type of conversion yourself, what kind of gains (or losses) can i expect? is there truly going to be a noticecable seat of the pants difference? will it change my cruise speed or fuel consumption? what can you tell me? i want to know that i am spending money in the right direction. if thats possible with an airplane, haha!! thanks again for all this great information, i truly appreciate the help.

aero101 · Post by **aero101** » Thu Jul 19, 2012 12:26 pm

Having done these changes on this prop on customer's aircraft, I don't think cruz speed will change much, but you will find glide performance decrease due to larger disk drag created by larger diameter. The M4's that we did, one was a land plane and we threw on ABW 31" tires, found to shorten up T-O roll from about 500' to about 300' and if course some of this was related to higher AOA of 31" tires? The other M4 was a floatplane that was somewhat marginal with original prop, reduced the T-O distance almost 50% in like conditions. The longer prop on my MX7 was the single greatest improvement I made both on wheels and floats. I think you'd find that yes, you will be able to feel improvement in seat of pants, it will help considerably on wheels, and probably help even more on the high drag penetration sks. The 82" does get pretty close to ground / deep snow on the prop clearance unless you hold 3-pt attitude, would suggest that longer gear from ABW may be answer for that?

pancake · Post by **pancake** » Thu Jul 19, 2012 10:18 pm

great info, the seat of the pants feel is exactly what you described. what powerplant/prop combo were on the m4s? what kind of difference would you expect to see between an 80 and an 82 inch? also sounds like the extra drag would almost be like longer flaps.

aero101 · Post by **aero101** » Fri Jul 20, 2012 9:44 am

Both M4's were the 210HP conti's... Not sure that difference between the 80" and 82" could be measured except with a pull scale measuring the static thrust produced, I'm sure there'd be a couple pounds difference...

pancake · Post by **pancake** » Fri Jul 20, 2012 1:47 pm

great info, i will start looking for one. thanks again for all that, i truly appreciate your time.

pancake · Post by **pancake** » Mon Jul 23, 2012 12:57 pm

I looked up these engines online and found that the differences is the dampers, some have two six order dampers and some have one six and one 4.5. I have never rebuilt an airplane engine so I am not familiar with what that means exactly. Mine is a "D" model with two six order dampers as I understand. I found an ad for a 2A34C203/90DCA-14 for a hawk XP with a "K" engine which I read has one six and one 4.5 order damper. Will this work? Can you explain what the damper order is exactly?

aero101 · Post by **aero101** » Tue Jul 24, 2012 9:43 am

The simple explaination is that it's about managing the torsional vibration created when engine running and as you have noticed the IO360 has a whole range of different orders or where these vibs are being damped out along length of crankshaft. The STC that installs the 'A' engine on the Stinson allows for the installation of this prop which means that at some point in STC process a vibration survey done. The A and D engines are basically the same. The prop you found is only a 76" one though. Take the 90" (orig mnfr'd length) subtract the -14" at end and that makes it 76"... you would want a -10 or -8 which would be a 80 or 82" prop.

YELLOWMAULE · Post by **YELLOWMAULE** » Tue Jul 24, 2012 9:56 am

The model number is right but for the maximum gain, this being a -14 prop is a marginal gain if any. The -8 or -10, That's the way to go I believe. Huge difference there like Jim.
As I recall, didn't the M-4 220 and M-5 220 have an 82 or 83" Hartzel? That Should set a precedent for your airframe/prop/ground clearance.

82 inch prop install on M5 210C

82 inch prop install on M5 210C

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