I just wanted to provide my unbiased opinion on a few modifications I’ve completed over the last year. When I was researching some of these beforehand, there wasn’t a ton of information. Hopefully this will help provide some additional perspective in the ecosystem.

MT 2 blade vs. Voyager: The MT worked just fine at sea level. Take offs were adequate for grass strips in New England. It helped CG and flew “fine”, but it wasn’t until I got out west that I really saw the pitfalls of this prop. On that first trip out, I was really struggling to climb over easy passes while slightly loaded and the plane was not performing like it should. High DA takeoffs in backcountry settings weren’t just suboptimal but downright too close to the margins. Accounting for DA and weight, my takeoff distances were significantly higher than POH numbers even though I had Sportsman and WingX at this time. Additionally, I broke 3 starter adapters during my affair with the MT. I know the prop wasn’t the root of the problem but it definitely exacerbated any other slight issues. One incident left me stranded in Mexico at 110 degrees F. I finally bite the bullet and bought a Voyager. Screw the CG, as long as I never have to be stranded in Mexican heat like that again (long story short, I had to take a taxi all the way back to the states).

The Voyager is better in every way. I was originally worried about speed loss vs the MT but was very surprised to see that I gained 3-4 mph! That wasn’t supposed to happen. The 2 blade MT is supposed to be a fast prop. Maybe it is but the Voyager is faster. As far as performance, I don’t want to get into butt dyno results. Additionally, I think there are too many variables to accurately measure takeoff distance comparisons, so I just did a simple climb test driven by the autopilot. It may not be perfect, but it is a simple way to test the props with few variables. I did two climb tests, 110 ias, 5000’ climb, WOT, 2700 rpm. I couldn’t climb steeper because I am cht limited. The base of the climb was 4000’ density altitude. My hope being this would account for some pressure and temperature difference and give the most accurate comparison. I loaded the plane up with bags, a 90 lb dog, and 104 gal of fuel to do these tests. My theory is that a lot of people testing a new modification will fly the plane light because they want to feel the new performance and sensations, but in reality we should be doing these tests high/hot and heavy. So I did my best to load it down and test high DA conditions. The MT completed this test at an average of 714 fpm and the Voyager at 790 fpm. Although it doesn’t seem like much, that’s a 10.6% increase in climb performance with the Voyager. I was only able to climb at 110IAS for this test because of temps but I can imagine that climbing at true Vy the Voyager would show even larger gains. You can imagine this translates to takeoff distance as well especially since the Voyager will spin 2850 vs the limited 2700 of the MT. Those are the most straightforward numbers I could obtain. If you have a o470 or low compression PPonk, mainly flying at low DAs I’m sure this prop would be just fine. On an IO520 that can spin 2850 and at high elevations, the two blade MT was absolutely the wrong prop for the mission.

Wing X: it’s been talked quite a bit on here so I’ll keep it short. Absolutely a nice increase in climb rate and decrease in takeoff distance. I’ve heard some people say it will increase your climb by 400 fpm but that wasn’t the case for me. Sorry I don’t have real data on this one but I’m seeing generally 150-200fpm increase max. I wouldn’t call it a miracle drug. I did make the mistake of loading my plane up to 3300 lbs for my third landing with the new big wing. I was worried I may float down the runway with all that additional lift. Not the case. I came in too slow, got dropped on my ass, bounced, and abused my airframe. Humbling experience. Additionally, you will notice you will have to be a little stronger on the rudders to keep it coordinated but you’ll get used to it quickly. I didn’t see any negative effects in cross winds. Same as any plane, aileron control, and keep it straight. I would absolutely do it again but it would be after Sportsman and Voyager.

Surefly: The short answer is that I would only do this modification if I was fuel injected with Gamis and running LOP. I saw a definitive increase in CHTs. During the summer with BW, I’m already struggling to keep temps down, the last thing I want is an increase in CHT. So this has been a love hate for me. The advanced timing kicks in under 24” MP so it is super important to keep an eye on your gauges and temps. For example, I was at 10.5k ROP In Idaho backcountry. I needed to check out a map and do a little route finding because of weather. On standard mags, you could never get to critical temps at this altitude but not with Surefly. I looked down after a few minutes and I was at 420f CHT! The timing advances so aggressively (up to 36 degrees btdc) that I was in serious territory of engine abuse. Once you know how to manage the Surefly it gets easier but engine monitor is absolutely necessary. Where the system really shines is up high and LOP. Before my engine would begin to run rough at 50 LOP but with Surefly it will run perfectly smooth 100-110 LOP. You could use the more efficient burn of advanced timing for additional fuel savings by running leaner, but I choose to redeem my Surefly nuggets as extra airspeed. So I’ll run 50 LOP and I see a much smaller drop in airspeed as I transition to lean compared to a standard mag. At the end of the day, I don’t think the juice is worth the squeeze unless you’re running variable timing and LOP. If you are, you will see more airspeed during those lean operations for a given power setting and therefore better mpg.

Earth X: The install is harder than a simple swap; however, 100% worth it. My one year old Odyssey and big energizer starter were always struggling to make it past compression stroke of the 520. Every time I started the plane, my heart rate spiked. Would I kill the battery or break an adapter today? This combination with a light MT is the secret sauce to starter adapter mayhem. The EarthX changed all of that. It is 10 lbs lighter and spins that big metal Voyager fast enough to take off a finger. It’s beautiful to see. Enough said.

Desser Aero Classic 8.50x10: I’m just putting this info out there because I don’t think this tires gets enough oxygen. 185s can’t run Goodyear 26s. They also can’t run Desser 8.50x6 because the load rating is too low on this tire for the high gross of the 185. Along comes the Aero Classic 8.50x10 6 ply. This tire has a true diameter of 25”, no tread, 20% less drag and 6 pounds lighter per wheel/tire assembly than 29” ABW and it has a high load rating. This tire doesn’t get much attention but it is a great compromise tire for some people. Faster cruise, better climb, and for most of us 25” tire will do everything we want. The ABW 10x10 STC specifically states 8.50x10 6 ply tires in case anyone is wondering on the legal aspects. You don’t need Grove wheels/brakes to make it happen.

Hope this helps someone out there questioning these modifications. Feel free to shoot me a message for more info.

Awesome report! Great to know your thoughts on the voyager vs MT, I’ll be going with a Voyager to replace my 2 blade Mac when funds permit. I agree on the Desser 8.50x10, It’s the perfect 185 tire for many of us. I’m currently waiting patiently for Grove to manufacture a new round of 10” wheels and brakes so I can do these tires tubeless. I have a Grove 10” setup on my Bearhawk Patrol and run both 31” Dessers tubeless and 35” ABW on them. The Groves are top shelf and the Dessers are wearing like iron. Question on your 8.50x10s….are you running them tubeless on Grove wheels or tubed on ABW wheels? From what I discern from the stc paperwork, grove is the only tubeless option. Thanks again for the report, much appreciated.
Cheers, Mike

ington6 wrote:...... 185s can’t run Goodyear 26s. .....

Curious why not?

Im running with tubes at 19 psi. I’ve only had a few days on them but I did some very hard braking, short landings on pavement the other day and haven’t seen any slipping. I’d prefer tubeless of course but this is my setup for now. Also, the sidewall doesn’t feel super stiff like the GYs. In my opinion it is a nice balance.

There are just no STCs for 26” Goodyears on 185. I believe the GY are actually a little smaller than the 25” 8.50x10 Dessers as well.

I'm really curious to know what exactly about the design caused the poor performance with the MT prop.

Disclaimer: I love my Bushwheels but….. another interesting aspect of the 8.50x10s is that I’m fairly sure these have decreased takeoff roll compared to ABW. Even highly inflated Bushwheels would squat in the dirt at 1000rpm, not moving an inch at this low thrust. The Dessers want to get moving. If your feet aren’t completely on the brakes at idle, the plane is going to want to travel somewhere fast. It’s a small point but something noticeable and translates to takeoff roll. That is until your on a very soft beach…then the BWs obviously win. All depends on your mission I guess.

Im no specialist but we can look at the basic dimensions. The Voyager is a 86” three blade prop vs a two blade 83” MT prop. That is significant amount more blade being thrown around. I’m not saying more is always better, but the two blade doesn’t seem to be enough prop for a 520. Also, the MT is limited to 2700 rpm while the io520 is legally permitted to spin 2850 rpm. There is an additional 15 hp at that rpm.

A common argument I’ve heard for the MT is that it is designed to make its most thrust at 2600-2700 rpm. Ok great, but we know the 520 makes 285hp at 2700rpm. Shouldn’t we want a prop that is designed to make the most thrust at the peak horsepower rating for that engine? I know it’s more complicated than this once we start talking tip speeds; however, generally we should want a prop that’s designed to make most thrust at an rpm that matches the engines power curve. Correct me if I’m wrong. See above, not a specialist. Just a guy who likes to nerd out on airplane stuff.

Good Mod Reviews. I have not posted on this subject before but I tried an 83 in MT 2 blade on my 180 for a brief period of time. I loved the weight loss and the improvement in CG but the performance was really not any better than my 78 inch Hartzell. The MT might have been 1 knot faster. I measured time to climb from sea level to 9000 feet. It was identical in both airplanes - about 10 minutes. Take distance/Landing distance was a little shorter in favor of the MT. What I really didn't like about the MT was the noise it made. Triggered a migraine headache for me. Which was ultimately the deal breaker. Obviously there are advantages to having less weight and improvement in the CG but the risk of the start adapter breaking make having a heavy prop out in front more appealing. 3 adapters and getting stuck in Mexico in 110F heat - Fuck that ! So I went back to the 78 inch Hartzell 3 blade. I probably need to buy a Voyager and likely will in a few years. Prop physics is complex and in the end we are trying to extra as much trust as possible from our engines. From what I keep hearing - the Voyager maximizes energy extraction from a 520/550 engine.

I am going to keep my slicks. Engine runs cool at all altitudes. Can fly in the summer with Cowl Flaps closed and still keep all of the CHTs below 380 which is awesome. I can also run LOP < 4K burning 8.5-10.5 gph depending on the power setting. I don't run over 60% LOP.

I have a sportsman cuff. I love this mod. I think it is must have item for a pre camber wing Skywagon or 182 for that matter. I have recently been flying a 185 with Wing X/Sportsman IO550 combination and this plane is a real performer. The reduced roll rate is minimal and if had a wider hangar or was better at parking airplanes I would consider this modification.

I will make a plug for Titanium Landing Gear. Just because they are super strong (essentially indestructible) and I saved 36 lbs. I have trimmed off a lot of weight in my airplane over the years and while this is an expensive mod it is worth it.

I am curious about Earth X. Can they be mounted up near the firewall where my Odyssey sits or does it need a field approval ? I just replaced the J16 but maybe having some more weight savings and a stronger battery is the way to go.


Josh

Not posting to bash Desser, just want my BCP buddies to know my experience if they are considering Dessers.

I think the 850x10 tire is a great size and too often overlooked. They are a great size for me. Unfortunately after 6 months the tires were so weather checked I couldn’t convince myself they were safe to use. I emailed Desser about getting warranty replacements. They asked what PSI I was running them at and I told them. 25psi at first then down to 20psi. They told me the tire failed because I was running them at a “VERY low pressure” and not at the pressure required by the TSO which is 42psi. I tried to call them several times and sent a few emails but never could get them to respond after I questioned them on selling a “tundra tire” that required 42psi of air pressure.

Pretty frustrating to get a 10” wheel set up and tires to go with them only to have them last 6 months. It’s a great size though so I hope you guys have better luck than I did.

Oh wow. Super good info on the Dessers, Whee. I wonder if there could ever be insurance repercussions from something like a ground loop of tire pressures were too low.

ington6 wrote:....There are just no STCs for 26” Goodyears on 185.....

FWIW it's hard to believe but although there are STC's for the 26" GY's on other airplanes,
as far as I know there isn't one for the 180/185.
Field approval required, which can be no big deal or a huge PITA depending on which FSDO you're dealing with.

Dog is my Copilot wrote:....I am curious about Earth X. Can they be mounted up near the firewall where my Odyssey sits or does it need a field approval ? I just replaced the J16 but maybe having some more weight savings and a stronger battery is the way to go.
Josh

https://earthxbatteries.com/list-of-stcs/

Earth-X has an STC for the 180 through the K model, but for 12V systems only.
But I believe it is to replace the standard 35-size gill or concorde in the original battery box.
If you already have an approved firewall battery mount,eitehr STC'd or field-approved,
it might be OK to install the earth-x there, using a combination of that approval along with the earth-x stc.
But that's a question for your IA and/or FSDO.

Also worth sharing, the new TSO EarthX for 180/185 did go through a slight size adjustment so it does fit firewall battery boxes now. There were problems with the old ones being .1” off.

Good reviews Ington6!

Not too long ago, I switched from an MT 2 blade on my 520 powered 180 to a 86" Mac 401.

While I haven't done any proper testing, I would say that I prefer the Mac 401 for everything but the weight penalty.

I was expecting a significant speed reduction, but I actually think I picked up a knot or two. The Mac pulls a LOT harder high, hot and heavy, which is where I often operate. Light at sea level, the takeoff and climb are truly remarkable.

The big Mac is smoother, and much more confidence inspiring.

I have seen some serious airworthiness concerns with the MTs, but those are stories for another time.

This is indeed an interesting debate.

I have been an MT reseller for almost a decade now, and have installed several on customers airplanes over the years. I like the weight savings, the quiet, and they way it spools up and brakes. I also love the support I get from McFarlane (now selling the props) as well as MT USA (in FL) and MT Germany.

That said, I have seen many broken starter adapters, including on my own airplane. Why it happens and how it can be (perhaps) mitigated are also topics for another thread...

On my personal Skywagon, I have run a 2B MT, and then a 3B. I was not impressed the performance of the 3B, so I went back to the 2.

I am always curious and like to keep experimenting, so recently I started selling the Hartzell; have sold one, and am in the process ordering a second...

Lots of good friends now running the Voyager with great results, and I've been more than impressed with the folks I've dealt with at Hartzell... although not a long experience with the prop so far, Im pretty much sold on trying the Voyager on my own buggy... so I guess we shall see.

(the fact that my bird is pickled and I haven't flown it in a bit is also a source for ridicule on a separate thread.)

I know a few guys running earthx batteries on their firewalls. One of them had problems with battery overheating, even after trying the cooling case that earthx sells for improved temperature control. Tried blast tubes etc. He tried a new battery as well, but no luck. The others seem to be operating just fine (so far), but they are also in cooler climates. I’ve used one for some time now in a cub with no issues, but it’s inside the airframe. I’d like one on the firewall of my 180, but don’t think I’m ready based on pireps.

Has anyone else had any issues with them in their engine compartment?

Disclaimer.... I have an MT on my husky, so not an apples to apples comparison. I love it! I've got a carbon sensenich on my RV-7 and until this MT, it was my favorite prop. On the husky, the MT is the smoothest prop/engine combination I have ever flown. My home airport is at 8,200 feet and when the DA's are in the teens, I'm still off well under 1000ft. If I had one gripe about the MT, it's that the damn thing whistles.

I have an earthX on my RV and it's the best battery I've ever had. It's on the firewall and has never overheated. I haven't done anything to cool it - Literally installed it five years ago and have done nothing else. I did leave the clock in the on position and drained it inadvertently. The BMS did it's job and I reset it and put it on a charger that EarthX told me to use and have had no additional problems. I ordered the earths STC and upgrade kit for my Husky.

Great info guys!

I love my MT prop on my Husky, best prop for a Husky and other airplanes in my opinion but if I had a 185 I would go with the Voyager. I flew one on a buddy’s 185 and it was very good.

Kurt

Great write up Ington6, thank you for taking the time to write down and post your findings, I’m sure they will be helpful to someone.

Kurt

I have the 8.50x10 Airtrac ribbed tire. Love it. Wears like Iron, no checking issues. Significantly bigger footprint than the 8.50x6 for soft field Ops. Some folks don’t t like the ribbed tire compared to the smooth tires cause they throw rocks. I added a mudflap/stone guard, so no issues throwing stones. I run them at 12-15 PSI. No slippage, even when squealing on tarmac at gross. I also think the ribbed tire at those pressures gives me better braking than a smooth tire on soft green grass, which is a lot of what I do.
I have had an MT 3 Blade for probably 15 years now. (C180, O-520, 3190lb Gross) I have always liked the performance and the light weight. One broken starter adapter spring until I got the EarthX and figured out correct technique, always keep it cranking until it starts (carb engine), made sure I have the heavy duty old style starter and the timing ect is all correct. No issues since. No structural issues but it is hard to keep them looking good cosmetically. The paint peels and the skin at the end of the blade tends to split a little from blade flexing, It has had one refurb and paint but same issues. The Voyager seems to be the go to prop nowadays. Thats probably what I would do now.
I have also had an Earthx on the firewall for probably 10 years. No issues. Light and HUGE cranking power.

Great info here.

That they've resized the Earth-X to fit existing battery boxes is interesting for sure. Might have to look into one of those.

I've done the Wing-X now on two birds, first my 180B and now my 185. For flying floats it's gold, I would do it instantly. I think though that if I was flying wheels only I'd hold off until I felt it was a very real need. This just based on the price. I'd do all the other mods first and if I still felt I needed Wing-X I'd do it last, but probably before shelling out for a major engine upgrade.

One combo I'd like to try out sometime but I don't want to pay for, would be a Robertson equipped wagon with the Wing-X as well. I'd be curious how it compared to mine.