Engine upgrade: To Pponk or Texas Skyways?

[Henning]

You get a 275hp engine as a result of mating 470U crankshaft to low comp 520 cylinders. De-rated for longevity, I guess.

O-520/TS sports GTSIO-520 jugs if I remember right

Poor efficiency though.

 

[txflyer]

IO-550 C180 flies very nice, but tends to be nose heavy (think if you are comfortable with carrying lead in the back) and you do need to watch those CHTs at lower alts in hot climates.
You might already know all that but I figured I'd throw my 2c in

You could trim some of that weight with an MT prop.

I know mine shaved 11 pounds off the nose. That much weight coming off the very front CG station is a huge difference, enough that you can feel it in a 180.

 

[Ted]

Poor efficiency though.

Lower efficiency, but if you wanted an easy path to the MoGas STC, that would be it. Especially with a carb.

You could trim some of that weight with an MT prop.

I know mine shaved 11 pounds off the nose. That much weight coming off the very front CG station is a huge difference, enough that you can feel it in a 180.

The MT props do reduce weight, however it seems a disproportionate number of people I talk to have issues with them, such as the hubs getting "stuck" and turning them into fixed pitch props prematurely, requiring an overhaul. I don't hear of as many issues with Hartzells and McCauleys beyond just getting old and the seals wearing out.

Do you find your MT to be quieter, louder, or about the same? It seems most of the MTs I ran (in test cells) were louder than their Hartzell/McCauley counterparts, with Hartzell typically being quieter than McCauley.

Personally, I'd love to get a couple of new props on the 310 that would reduce the noise a few dB.

 

[txflyer]

Lower efficiency, but if you wanted an easy path to the MoGas STC, that would be it. Especially with a carb.



The MT props do reduce weight, however it seems a disproportionate number of people I talk to have issues with them, such as the hubs getting "stuck" and turning them into fixed pitch props prematurely, requiring an overhaul. I don't hear of as many issues with Hartzells and McCauleys beyond just getting old and the seals wearing out.

Do you find your MT to be quieter, louder, or about the same? It seems most of the MTs I ran (in test cells) were louder than their Hartzell/McCauley counterparts, with Hartzell typically being quieter than McCauley.

Personally, I'd love to get a couple of new props on the 310 that would reduce the noise a few dB.

That's honestly the first I've heard of freezing hubs on MTs.

The issue I heard on the old one's the most was the composite leading edge was more prone to rock damage, but they remedied that with a stainless steel 'welded in' leading edge on the prop.

I do like my MT more than my previous McCauley. It may not be any quieter, because there seems to me to be no difference that's noticeable, but it sure is not louder. I would notice louder in an instant. I can say the MT is smoother, by quite a bit. It spins up faster and just feel's lighter for lack of better words.

On a twin, I would think the smaller diameter three blade MT would be quieter than my two blade because of the smaller diameter. But you also have another blade out there chopping the air, so I don't know how that works.....


1964 C-180G, 0-470-R, Sportsman STOL, G430W, GPSS, S-Tec 30, Alpha Systems AOA, BAC Shoulder harness', Pponk gear mod, H.I.D. wingtip wigwags, LED nav/landing lights

 

[moonshine]

That's a weird looking prop for the airplane. No negative connotation, just a statement on the unusual looks.
We had a new Hartzell 84" three blade on PPonk - didn't go any faster but it can sure climb

 

[Ted]

That's honestly the first I've heard of freezing hubs on MTs.

The issue I heard on the old one's the most was the composite leading edge was more prone to rock damage, but they remedied that with a stainless steel 'welded in' leading edge on the prop.

I do like my MT more than my previous McCauley. It may not be any quieter, because there seems to me to be no difference that's noticeable, but it sure is not louder. I would notice louder in an instant. I can say the MT is smoother, by quite a bit. It spins up faster and just feel's lighter for lack of better words.

On a twin, I would think the smaller diameter three blade MT would be quieter than my two blade because of the smaller diameter. But you also have another blade out there chopping the air, so I don't know how that works.....

The leading edge is another issue, and honestly I've seen such large chunks fall out of the things that I wouldn't put one on the 310 for that reason alone. However, we also go up to gravel strips in the middle of nowhere, which is a big part of it. The benefit of the design is that, while fragile, it is also fixable with 5 minute epoxy. So you can carry a prop repair kit with you for anything that doesn't actually fall off.

Diameter is the real driver in noise. We have 3-bladed props now, and would only go with 3-bladed again. We also have 520s, which is part of it.

Because the props on there now are a very old (~40 year old) design, I do believe that a newer one could get at least quieter if not also a little more efficient and maybe get an extra knot or two in cruise. But when I approached a friend at Hartzell asking about doing a one-off 337 for the props the basic response was "No."

 

[txflyer]

That's a weird looking prop for the airplane. No negative connotation, just a statement on the unusual looks.
We had a new Hartzell 84" three blade on PPonk - didn't go any faster but it can sure climb

Everybody likes the three blade look, myself included, but for my particular plane, with an 0-470, it's a little light in the ass for a three blade. But later, if I upgrade to an 0-470-50, the two blade is more efficient than the three in everything but climb. Great for floats, but not necessary for land planes.

I read enough good about the MTs, particularly on 180s to want one. The skywagon is a nose heavy bird, with a little forward CG problem, and the MT two blade addresses that problem better than no other. The STOL and over-all performance on skywagons in particular, benefits greatly from that much weight taken right off the nose.

So good or bad, that's why I went with an MT and the two blade.

 

[wabower]

I have extended baggage and carry the tool box and spare tire in the back. Problem solved.

Everybody likes the three blade look, myself included, but for my particular plane, with an 0-470, it's a little light in the ass for a three blade. But later, if I upgrade to an 0-470-50, the two blade is more efficient than the three in everything but climb. Great for floats, but not necessary for land planes.

I read enough good about the MTs, particularly on 180s to want one. The skywagon is a nose heavy bird, with a little forward CG problem, and the MT two blade addresses that problem better than no other. The STOL and over-all performance on skywagons in particular, benefits greatly from that much weight taken right off the nose.

So good or bad, that's why I went with an MT and the two blade.

 

[moonshine]

The leading edge is another issue, and honestly I've seen such large chunks fall out of the things that I wouldn't put one on the 310 for that reason alone. However, we also go up to gravel strips in the middle of nowhere, which is a big part of it. The benefit of the design is that, while fragile, it is also fixable with 5 minute epoxy. So you can carry a prop repair kit with you for anything that doesn't actually fall off.

For exact same reason we bolt chunks of aluminum to everything I send off to the boonies We had a guy on the Diamond board loose a chunk of the wooden MT in the outback. Plane was stranded there for weeks

I have extended baggage and carry the tool box and spare tire in the back. Problem solved.

Turbo-normalized IO-550 A185F I just brought home came with 40lbs of lead tied down in the back - weight distribution makes it a 3-pointer-happy airplane.

 

[moonshine]

Everybody likes the three blade look, myself included, but for my particular plane, with an 0-470, it's a little light in the ass for a three blade. But later, if I upgrade to an 0-470-50, the two blade is more efficient than the three in everything but climb. Great for floats, but not necessary for land planes.

I don't mind the look at all, that blade shape just looks unusual for this particular plane. Like a Yak-52 with scimitar blade prop on it.

 

[txflyer]

I don't mind the look at all, that blade shape just looks unusual for this particular plane. Like a Yak-52 with scimitar blade prop on it.

It would look better imo if it were polished with red tips, but no go on polished look with MT. So I chose the grey instead of white or black.

I get what you're saying. It's a modern look on a retro plane. If my plane had a fancy modern paint job all over, it may look more like a fit. But I can see what you're talking about.

Performance was my goal, and I think it looks better than the old black mac I had. I have that prop, and it's bolted down in the MT box ready to ship if anyone wants one. MT ships it's props in an incredible nice wooden box by the way.... not cardboard.

 

[wabower]

I've only been flying 180's since 1957, so don't pretend to know all that much about them. But FWIW, I think changing props that aren't bent is like pouring perfume on a pig.

 

[txflyer]

I've only been flying 180's since 1957, so don't pretend to know all that much about them. But FWIW, I think changing props that aren't bent is like pouring perfume on a pig.

I've only been flying one since 2007, and know all about mine.

She smells good while I'm going a little faster, a little slower, and smoother too.

 

[Ted]

For exact same reason we bolt chunks of aluminum to everything I send off to the boonies We had a guy on the Diamond board loose a chunk of the wooden MT in the outback. Plane was stranded there for weeks

Yep. Meanwhile when I got a decent nick on my Hartzell aluminum prop about 1000 miles from the nearest replacement (long ways north), I filed it with my Swiss Army knife and flew home. It was severe clear and the plane had just the two of us in it, so very light weight and low risk. My mechanics about had a heart attack, only to find it was within the Hartzell service limits. With an MT I'm confident I would have benn stranded.

If all you do is go to and from paved strips, I wouldn't worry about it and would consider them for weight reduction if the data indicated equal or improved noise/speed characteristics, but the reliability would have me concerned.

I've only been flying 180's since 1957, so don't pretend to know all that much about them. But FWIW, I think changing props that aren't bent is like pouring perfume on a pig.

So if I want to replace a prop, I should bend it first? What if it's a Q-tip?

 

[wabower]

Clearly an engineering problem. I'd try to find one that knows something and ask him.

Yep. Meanwhile when I got a decent nick on my Hartzell aluminum prop about 1000 miles from the nearest replacement (long ways north), I filed it with my Swiss Army knife and flew home. It was severe clear and the plane had just the two of us in it, so very light weight and low risk. My mechanics about had a heart attack, only to find it was within the Hartzell service limits. With an MT I'm confident I would have benn stranded.

If all you do is go to and from paved strips, I wouldn't worry about it and would consider them for weight reduction if the data indicated equal or improved noise/speed characteristics, but the reliability would have me concerned.



So if I want to replace a prop, I should bend it first? What if it's a Q-tip?

 

[ron22]

I see in 2002, Pponk issued a service information letter recommending tear down and rebuild of effected conversion engines due to the wrong crankshafts and 8.5 compression pistons being installed.

Since there is no STC for auto gas I think the 8.5 pistons would be better if you are running 100LL

 

[wabower]

The -50's come in different configurations. My case started life as a TSIO-520.

 

[Ted]

Clearly an engineering problem. I'd try to find one that knows something and ask him.

Where on earth would one find such a person?

 

[wabower]

Craigslist help wanted section would be my best resource for such talent, unless a lurker appears in the meantime. But you might find one closer to your cube at work. They are somewhat elusive creatures and difficult to trap, especially if any work appears to be eminent.

Where on earth would one find such a person?

 

[Ted]

Craigslist help wanted section would be my best resource for such talent, unless a lurker appears in the meantime. But you might find one closer to your cube at work. They are somewhat elusive creatures and difficult to trap, especially if any work appears to be eminent.

Well, the engineer who's currently attempting to have a conversation has accused the person he bought his truck from of parking his (seller's) new, larger truck right next to said person's (buyer's) old, smaller truck just to show off. Meanwhile, said person said "I never should've sold him that truck. He just comes by and complains every time it makes a noise."

If you had a hard time comprehending that, I had an even harder time figgerin' WTF this guy was thinking then, or any other time.

Maybe I'll drive next trip.

 

[wabower]

Back home they said "All that glitters is not glit, and all that titters probably ain't either."

Well, the engineer who's currently attempting to have a conversation has accused the person he bought his truck from of parking his (seller's) new, larger truck right next to said person's (buyer's) old, smaller truck just to show off. Meanwhile, said person said "I never should've sold him that truck. He just comes by and complains every time it makes a noise."

If you had a hard time comprehending that, I had an even harder time figgerin' WTF this guy was thinking then, or any other time.

Maybe I'll drive next trip.