Cessna 185 IO-520 or IO-550

Dave,

I know of three guys running the MT on 185's. Two are on wheels, and I really haven't quizzed them on performance, but they seem to like it. I hope that's vague enough.

The third is on floats, and I have discussed specifics with him. Just so's I don't exceed my 30 year old college physics education, I think we'd mostly agree that, whether it be torque, hp, gas, or whatever, a floatplane does require a certain amount of additional "oomph" to get underway, so I think that's a good test of a prop .

That fellow is happy with the prop. He replaced a two blade seaplane prop on that airplane, and had lots of experience before and after. He said the MT pulled noticeably harder on takeoff, and in climb, but he actually lost a few knots of cruise speed at a given power setting. I seem to recall he said 4 knots, but that's a guess. He is happy with the prop.

I think the "cracking" issues were in part a non issue, but there were some real issues there as well. Also, they had a few of the leading edge strips delaminate. To MT's credit, they have been fixing the props that had these issues at no cost to owners, though some airplanes have been down for a while and the owners have had to pay for removal/installation. They've changed the design of the tips some now to prevent this from happening again. Also, I think most of the props they're selling now are 205 cm instead of 210 cm, maybe to help to prevent this as well.

I'm currently working on putting one on my airplane, as a matter of fact. I have a Hartzell 80 inch, which is subject to the hub AD :evil: . There is now an STC for 170/172/175 with 180 hp, and also a two blade for the 185 and the three blade is approved on the 206, I'm told.

I like the things. On my airplane, one would take 30 pounds right off the nose. That's huge.

My experience with them in the field is that they work. Another pilot got my work airplane on its back with the MT on the nose, and it didn't even tweak the flange, which is good, cause the prop was a goner. I think a metal prop would have been equally hosed, but in the process COULD have applied more force to the crank flange. That's pure speculation, and we'd all like to think we'll never get a prop strike, but......

MTV

Dave-

Crash had a post on here about his prop selection.

Tim

MT tested their props on Bonanza's and several Cessna's. Helped the Cessna's but slowed the Bonanza's down.

I would like to see what MT can do for the Lycoming and Continental 4 cylinders on our rag and tube type aircraft.

Thanks Mike, Tim, Steve.

One of my customers flying a hotrod 180 (IO-470, early light-weight airplane, great pilot with lots of 180/185 experience and much time in this particular a/c) took off a 3-blade McCaul to install the latest, greatest Hartzell and lost top-end speed. The Hartzell spinner is sure a magnicficent appendage, though. (smile)

Others running the 86 and 88 inch 2-bladers claim that they pull harder than the 3-bladers, and admit there is a noise issue. I had heard one of the 180/185 performance gurus (whoever they are) had tested a bunch of different prop/engine/airframe combos on the same day and had a good table of results.

Anyway, someone may have noted in this thread that a propeller is accelerating a column of air. Whatever moves the greatest mass(!) of air with the available HP at an acceptable RPM (prop noise) will win, I think!? (This is a simplistic statement Andrew )

I had hoped someone here had a line on that testing table.

The reason I question what a "180/185 guru" is stems from the fact that I have put a few of these a/c together and been around them for long enough to know what breaks and wears on them, and I wouldn't advertise to be a guru, but some others would.

DMC

Perhaps not guru status Dave - but you're at least part of the 180/185 "cognoscenti"

Got to use that word twice in one thread - cool!

Dave, SOMEBODY should be giving you a hard time, right? But nobody has risen to the occasion lately - - so - -

It would be the greatest product of mass*velocity for that column of air.

Thrust (force) is the change in momentum (mass * velocity) in a time interval.

Dave,

What are you talking about??? There are LOTS of 180/185 Gurus over on that Skywagon site :lol: . That's what they say anyhow.

MTV

cognosc-what?? I thought it was only the gun-writers who used that word.

Geezer, yes, that's why I underlined the word "moves". As in "takes the air from here and "moves" it to there. Of course we assume that it will take time for this to occur. Yes, I'm taking your clarification with a bit of a twinkle in my eye. Thank you.

Mike. I have spent zero time on the skywagon site. I'm sure there is somone over there that knows everything. I'll just keep repairing my customers' aircraft in the same areas that every 180/185 breaks. Those guys will continue to install the nicest panel EVER done.......and my interiors will still come out looking classier, and yet, remain functional and lightweight with a modest panel.rantatatntanrantnatntnantnranttarnatrantyadyaydyadyydaydyyada.

ME

..anyone operating a Lycoming powered 206?

There is one based here. I have been up to the other shop to look at in when the other mechanic on the field is messin' with it. Lot of stuff under the hood and a lot of space behind those two glass things in the panel.

Flew a Lyc 206. Nice plane, maybe not the bushiest plane. It had the small Mac scimitar prop. Smooth as smooth could be. That in contrast to serial#33 206. That was a 2 blade 285hp plane. Ripper to 10k with 6 jumpers. Fly a couple of hot-rod io-550 206s now. One with a RStol one Flint wing ext. They rip, and pull the hardest of any 206 with a Big Mac.