If anyone is interested... Last month I did a small project for McFarlane where we did a side by side comparison between the 2B MT and the 3B Voyager... it was really fun to get back into making an aviation film.

In disclosure, I was not compensated for the production or testing. The customer was offered the prop at a wholesale discount, but the agreement was not tied to any positive feedback. To their credit, McFarlane only wanted a true honest interpretation, which is what we delivered.

I had one Skywagon customer who I sold an MT to when we first found his airplane. This past Feb, we pulled it off to try the Voyager. At first blush, we were shocked to see that he gained 10-12 mph in cruise, but after 4 months of flying, he felt his takeoff performance had suffered, and that he just didnt like the way the airplane "felt" with respect to the CG.

I have had 14 year relationship with Flight Resource, and feel very strongly about McFarlane, so I reached out to McFarlane to see if there was an opportunity to glean some information.

McFarlane agreed to help get the customer back into an MT in trade for some honest feedback, so I put this little project together.

The context is critical here... this exercise can ONLY be representative of a stock 180 with an O-470R. This is because the 470 spins at 2600 with 230 HP. The MT has a max RPM of 2700. This testing heavily favored the MT rather than the Voyager because (IMHO) the stock 470 just doesn't have the HP to take full advantage of the Voyager and we are not seeing the performace we do on a stock 185 with an IO-520.

Choosing the "right" prop is so difficult... does that even exist?? With the barrier of entry so steep ($20k for a prop??,) it seems that the stakes are incredibly high. None of us wants to end the film hearing the knight say: you chose poorly.

I have always loved how the MT flys... it's smoothness, it's lightness, it's sound... the quick throttle response and the engine braking are really a joy, but if the Voyager just simply pulls harder; whats a girl to do??? To this end, I will be doing a similar exercise later this fall uising a hopped up -50 Pponk, which will be really interesting.

FWIW... our testing was quasi-scientific and really meant for an A/B quick comparison, so I don't want to hear any flack about calibrated radon filled wondnick catheters, acoustic DERs, or fluorocarbon outputs. We were just simpletons.

Testing was done in the same morning. Ceilings weren't the highest, so the time to climb was only to 3500'. At the end of the day, our experience was that the MT is much much lighter, which is really felt behind the wheel. The two props were identical with respect to noise, the time to climb was a wash, and the MT was 11 mph slower. (25/25 at 2500').

Where the MT really shone was in smoothness, and the takeoff roll. The Voyager showed roughly 500' vs/ the MT's 400'... and seeing how the take-off performance was the principle concern, the customer kept the MT.

I will say that I have seen more than my fair share of starter adapters break with the MT on a big bore Cont (including one on my own bird,) so for my money, there are a couple of MUSTS when running an MT.

1) make sure all your gear is up to snuff. Good plugs, wires, and especially mags that aren't sloppy and worn out.
2) make sure you run either a Bendix shower of Sparks, or even better, a Sure-fly... The Sure-fly will retard the timing at start where the kickback issue begins. (topic for a separate post if you want).
3) pay close attention to timing. We are dealing with almost 100 year old technology, so it's easy for a mechanic to have a "that'll-do" spirit. A lais·sez-faire attitude with a shriners cap on the spinner may not be the best approach.

Anyway, thanks to McFarlane for opportunity to conduct this exercise, and your continued support. One of the best aviation companies around for sure!

Both Hartzell and MT make a great prop, but the "right" one really depends on your mission and specific aircraft. If you want to discuss MT's or Voyagers, feel free to shoot me a PM.

This popped up on my youtube feed in the last week. You really did a good job with this video.

I hear you on your seat of the pants testing and results. I am struggling to see how climb could be the same with a 20% deduction in takeoff roll.

10 kt hit on cruise speed? No thanks.

C180_guy wrote:10 kt hit on cruise speed? No thanks.

Easy to quip...

Perhaps you didn't read the entire post as there is more nuance to what I am saying.

To some, speed isn't the most important thing. 400' take off vs 500' is pretty compelling... Unless you are flying a Bonanza. Then the cruise speed might matter. All depends on your mission.

Having a "legal" CG, an airplane that "feels" right, can be trimmed properly (hands off) on final, and gets off short from your hunting camp was the mission for the customer.

Josef wrote:I am struggling to see how climb could be the same with a 20% deduction in takeoff roll.

Yup... but keep in mind that these things can't be taken individually and many things are at play here.

The ceilings were low, and the time to climb was only to 3500 ft and he two props were within 5 seconds, which for me, puts the data in the "merely interesting" category. McFarlane had requested a climb to 10K, but it wasn't in the cards due to WX.

The real surprise to me was the noise. I had expected the Voyager to be MUCH louder than the MT, but in reality, they registered the same db on my little meter. I suppose this has to do with tip speed. There is a difference between 2600 rpm and 2850 for sure.

I think the real culprit was the weight. With the MT being so much lighter on the nose, and the O-470R only having 230 HP (presumably less now than two decades ago when it was new) the wagon was able to get up and go much quicker.

On a higher HP Skywagon, the reports I am getting from customers whom I've sold Voyager props to are that take-off roll is dramatically improved over the props they are replacing, but I have not definitively tested this myself so can't speak definitively to this. I have only had one other customer who has removed a 2B MT on his Skywagon ( IO-520 powered185.) Discussions with him about his experience were the opposite of my findings with the O-470 powered 180.

I think this comes down HP. The Voyager was made explicitly for the 185 (more HP than the stock 180.) The stock 180 just cant take squeeze out the juice the Voyager has to offer... From where I sit, all things considered, the 2B MT is the right prop for the stock 470 (with the electronic ign caveat mentioned above)

Bigrenna wrote:To some, speed isn't the most important thing. 400' take off vs 500' is pretty compelling...

Get a super cub? Bearhawk?

Bigrenna wrote:To some, speed isn't the most important thing. Unless you are flying a Bonanza. Then the cruise speed might matter.

Ah, that old worn out trope

Josef, there are more aerodynamic variables at play with climb than solely takeoff. A faster prop= more airspeed= more lift. It’s the same as coming to the realization that Bushwheels hurt your climb performance. For my flying, 185F, Voyager and 8.50x10s is the best performing combo. Love everything about the Voyager except the CG shift.

“I think this comes down HP. The Voyager was made explicitly for the 185 (more HP than the stock 180.) The stock 180 just cant take squeeze out the juice the Voyager has to offer... From where I sit, all things considered, the 2B MT is the right prop for the stock 470 (with the electronic ign caveat mentioned above)”

I agree 100 percent with this.

Kurt

Nice video. Curious what it was filmed with. No prop blur which I like.

Lucky for me the only thing our wagon "needs" right now is fuel in it.
We've got a stock O470R and an 82" mac prop.

Having recently swapped from a Borer on a 160hp PA18 to the Sensenich composite ground adjustable, I'm sorely tempted to upgrade 180 to a more modern design - the cub was a drastic difference. 180 prop being potentially triple the cost makes it something where I'd need a pretty sure bet, can't afford to gamble so the video above is appreciated and resonates.

Crystal ball wise, when the time comes to rebuild motor we're likely to go 470-50, so any prop we do would need to work for both now and then, hopefully we don't need prop before then. Right now my tea leaves indicate there's a good chance we'd go with a composite voyager.

That ain't a trope, bro. Count me in the "IDGAF" about cruise speed camp. Give me 100' on takeoff roll and 20lbs off the nose.

C180_guy wrote:

Bigrenna wrote:To some, speed isn't the most important thing. 400' take off vs 500' is pretty compelling...

Get a super cub? Bearhawk?

Bigrenna wrote:To some, speed isn't the most important thing. Unless you are flying a Bonanza. Then the cruise speed might matter.

Ah, that old worn out trope

An airplane with respectable STOL performance, suspension and prop clearance that can tolerate at least some off airport operation, and can economically cruise at 100 KTAS or better is an incredibly versatile machine. Owners use them for a pretty wide range of mission profiles. Not much point in passing judgement on where in that spectrum someone decides is the sweet spot for them.

Bigrenna is spot on regarding the 86" Voyager and the 230 HP 470.

The Voyager was specifically designed for a 300 HP motor (Take off power) to minimize take off distance and maximize climb performance. The added cruise benefit was a very nice byproduct.

The market asked for the STC to add the Voyager to the 180 market due to the very good cruise performance of the prop no matter what the HP of the motor intended. This is all different strokes for different folks.

In many applications the 2 blade MT is suitable per mission requirements. Certainly in the case Bigrenna stated his customer has the right prop for his mission. I'm very happy for both!

I have tested noise levels of the Voyager at 2700 vs. 2500 RPM. The difference is considerable on the order of 10-15% lower. I don't have numbers that pertain to take off roll and climb performance at reduced RPM. I've not been in a situation to test more was it required. On the other hand if take off performance is something I'm considering then I will go with full RPM.

MW

DreadPirateWill wrote:.....We've got a stock O470R and an 82" mac prop...... I'm sorely tempted to upgrade 180 to a more modern design - the cub was a drastic difference. .... when the time comes to rebuild motor we're likely to go 470-50, so any prop we do would need to work for both now and then.....

Curious which Mac you have now?
The C203 is a great prop, esp in the 88" length, at least for a 470R,
but unfortunately it's not approved for a ponk engine.
IMHO a stock 470 isn't enough engine to need or efficiently utilize a 3 blade prop,
and I believe that the only 2 blade Mac's that have been approved for Ponks are the older threaded designs like the C58 & C66.
Those are considered obsolete by McCauley & are not very well supported.

hotrod180 wrote:IMHO a stock 470 isn't enough engine to need or efficiently utilize a 3 blade prop,

Same story for the IO470. So, I take it the voyager is three-bladed. I emailed Hartzell to ask what two-bladed props they offer for the IO470 and I never received a response. I am still rocking the C203.

I tend to disagree about the IO-470 not having enough power for a three bladed prop. There are hundreds of B-55's out there with IO-470's running 3 bladed props. Many HP and many MAC.

MW

HP did and STC last year for a two blade of the stock O-470. I'm getting the specifics and will post.

MW

Blade model 8068. 82" diameter. Called "super scimitar" to public. STC covers all models of the 180 with any stock 470.

Hopefully this helps.

MW

185Midwest wrote:I tend to disagree about the IO-470 not having enough power for a three bladed prop. There are hundreds of B-55's out there with IO-470's running 3 bladed props. Many HP and many MAC.

MW

three-bladed prop is heavier and you lose cruise speed. was wondering if something was better than the C203 for the IO470F since we are having a prop conversation.

Slight thread drift but relevant. I recently installed a Voyager 86 ( thanks Greg) on my 180 with a 470R Eng. I removed a McCauley 203 88”. (For sale). My experience is
-Cruise at 3000 feet is 5mph faster.
-T/O from 0-50 is 3 sec faster. Used to be 12 sec. Now 9 sec. Significant but not sure what it equates to in feet.
-Cruise above 7000’ has maybe been the most significant. With 10-15 mph increase at higher altitude.

The first 2 test I did day of swap and are facts. The 3rd point is something that I noticed later with IAS holding higher value much higher in the climb.