I have an 180 hp aeronca sedan with the hartzell 76" constant speed prop. I was thinking of up grading to the 80" hartzell. I was wondering if anyone has any info on the performance gains of the bigger prop?
Thanks

I wouldn't do it. You will get some improvement in performance but will add a lot of weight for that performance. I would suggest the MT Ultra 2 blade, standard MT 2 blade or Hartzell Trailblazer composite, all 3 are much better props.

Kurt

Thanks for the info, i didnt realize it would ad that much weight over the prop i have. I am just looking at a blade change and adding a dampner to get rid of the rpm restriction.

I literally emailed MT today asking about a field approval for the 2 Blade Ultra on a Sedan.

You will get rid of the RPM restriction with any of the MT props and composite Hartzell Trailblazer.

Kurt

I'll second G44 on the MT prop recommendation for the O-360. I've run the 2 blade Ultra on a 180hp 172 and just put a 3 blade MT on my O-360 powered Maule. Both great performers for intended purpose and no RPM restriction on the O-360. The price of admission stings a little but once you fly one you'll know you made the right choice.

If you go MT and you can afford to lose the weight off the nose, Definitely go with a 2 blade. On the Maule I couldn't afford to give up 20 lbs due to loading and CG issues or I'd have done the 2 blade Ultra on it too. Plus I got a great deal on a used 3 blade off a Husky through Flight Resources.

I have the 80” Hartzell on my 180hp Sedan. I can tell you that the performance is significantly better in both takeoff/climb and cruise vs. the 76” Hartzell. The difference in weight between these props is only a pound or two. I have the O-360A1F6 engine with the balanced crankshaft so I don’t need the damper. The damper does weigh about 7 pounds. Either way you can run any combination of RPM/Manifold pressure you desire with the 80”, there are no restrictions. The 76” Hartzell was designed for the Mooney, it does not perform well on slower aircraft that desire takeoff and climb over cruise.

Burl has the paperwork for the 84” Hartzell Trailblazer more or less done. If someone wants to buy one from him for their Sedan, I’m sure he will finish up the paperwork quite quickly. He will either add it to the STC for the 80” Hartzell or do a whole new STC for that prop.
I am on the fence about getting a trailblazer for my Sedan due to cost. If others are interested, we could approach Burl with a group buy. I would think that he would give us a pretty good deal, as he wants to get this done for the new Sedans that he is producing.
The trailblazer would make a great prop for the Sedan. It would weigh a lot less than the 80” Hartzell and the damper would not be required. This weight reduction on the nose would be great for a Sedan on floats.

49_sedan wrote:I have the 80” Hartzell on my 180hp Sedan. I can tell you that the performance is significantly better in both takeoff/climb and cruise vs. the 76” Hartzell. The difference in weight between these props is only a pound or two. I have the O-360A1F6 engine with the balanced crankshaft so I don’t need the damper. The damper does weigh about 7 pounds. Either way you can run any combination of RPM/Manifold pressure you desire with the 80”, there are no restrictions. The 76” Hartzell was designed for the Mooney, it does not perform well on slower aircraft that desire takeoff and climb over cruise.

Burl has the paperwork for the 84” Hartzell Trailblazer more or less done. If someone wants to buy one from him for their Sedan, I’m sure he will finish up the paperwork quite quickly. He will either add it to the STC for the 80” Hartzell or do a whole new STC for that prop.
I am on the fence about getting a trailblazer for my Sedan due to cost. If others are interested, we could approach Burl with a group buy. I would think that he would give us a pretty good deal, as he wants to get this done for the new Sedans that he is producing.
The trailblazer would make a great prop for the Sedan. It would weigh a lot less than the 80” Hartzell and the damper would not be required. This weight reduction on the nose would be great for a Sedan on floats.

I'm leaning towards the MT because of the hub and no recurring AD's around it. The guys up here running them love 'em.

49 sedan, thanks for the info. I might be interested in the trail blazer depending on the price of it. The reason i was leaning towards the 80" metal prop was i found a deal on a used one. The weight savings of the trail blazer would be nice though.

My dad and I have had a 180hp sedan around since the 70s. And have tried all kinds of propeller combinations and have found a 82/41 gives the best overall performance. You just don't gain any thing with the constant speed prop other than more weight and expense.

What is your cruise speed with the 82/41 prop?

Stay with the constant speed prop. What you lose by going to a fixed pitch prop is the flexibility of running different power settings, like oversquare settings, and other advantages that the fixed pitch prop simply doesn't offer.

I have extensive experience with the 80 inch Hartzell on a 170B with O-360, a Husky, and my current Cessna 175 with O-360.

Unless you have the mass balanced engine that 49 Sedan mentioned, you will have to use the harmonic damper assembly with that Hartzell 80 inch propeller. The harmonic damper assembly on my airplane weighs 10 pounds, or just an ounce or so under. That's a big chunk of junk right up on your nose.

I have run a 74 inch Hartzell on one of these airplanes, then gone to the 80 inch Hartzell with damper assy on the same airplane, then gone to an MT 83 inch propeller, again on the same airplane. I've done the same with another airplane, except it started with a 76 inch Hartzell, but we then went through the same combinations on that plane as well.

There is no question that the 80 inch Hartzell pulls a LOT harder than the 76 inch Hartzell. In my experience, the 83 inch standard MT composite propeller pulls just as hard as the 80 inch Hartzell, but is a full 30 pounds lighter.

That's right.....the MT prop (or I imagine the Hartzell Trailblazer) weighs 30 pounds less than the 80 inch Hartzell and damper assembly.

And, as noted, any of the composite propellers do away with the restricted operating range on the O-360. The composite propellers absorb much of the vibration produced by this engine.

I'm on the fence over replacing my 80 inch propeller with a composite.....requires a big check, and I'm leaning toward other projects.

But, those composite props are sweet units.

And, don't even think about going back to a fixed pitch.

MTV

MTV, thanks for the info. i'm not sure i want to pony up for the MT or Trail Blazer, they sure would be nice though.

Your comment about just needing a blade change and damper assy. MAY be a bit oversimplified. Hartzell prop hubs are subject to a lot of ADs for corrosion. The reason I went MT twice in past.

So, you buy blades (which have to be cut down and contoured) to get to 80 inch, and hand your hub over to prop shop to install blades. Prop shop says “Oh, sorry, hat hub is subject to AD blah de blah....and failed due to corrosion.”

Now you’re buying a hub, blades, and damper. Really depends how old your hub is. But Hartzell loves condemning hubs.

Don’t ask how I found that out.

MTV

is a sedan with a 180 hp, underfloated on edo 2000s? Someone made that comment to me, but I haven't heard that before.

Just to give you some idea of a Sedans size...



This is my 5 foot 9 father standing in the cabin of a sedan working on a GPS installation in the dash... the seats are field approved PA-28 seats... these airplanes are big...

Brian


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I think a 180hp Sedan with MT Ultra to Trailblazer would be an incredible airplane! Let us know what you do.

Kurt

G44 wrote:I think a 180hp Sedan with MT Ultra to Trailblazer would be an incredible airplane! Let us know what you do.

Kurt

Oh my, a sedan with 180 hp/composite prop.. ya baby.. that would be an outstanding daily hauler.. stuff it and go. I loved my old sedan.. great airplane.. does everything pretty well, but nothing outstanding except that it has a huuuuge useful Load and a very wide CG.

Brian-StevesAircraft wrote:Just to give you some idea of a Sedans size...



This is my 5 foot 9 father standing in the cabin of a sedan working on a GPS installation in the dash... the seats are field approved PA-28 seats... these airplanes are big...

Brian


Sent from my iPhone using Tapatalk

The 15AC cabin is huge and it is the only 4 place airplane that I can walk around the cabin like that! (5’10”)[emoji1360]

With the left side seaplane door it just gets better and more open feeling too.

I should have kept mine [emoji24]

To get a field approval for the MT it’s an extra $2000, plus travel expenses. To Alaska that really makes this an expensive prop. I don’t know if I can justify paying $3000+ more for a prop than one that is covered by an STC.

You guys running the O-360s....what kind of speed do you get on wheels? Burl said in an article some years back 120mph plus is realistic.