I've got a couple new old stock shrouds that look like yours (minus the damage). They still have Cessna pick tags on them, but so faded that I can't read the part numbers. Send me some better pictures inside and outside with dimensions.

Yes, stock IO-520.

I can’t wait. I’ve been casually looking for an 86” Mac 401, but ever since the Voyager came out at Oshkosh I knew I was in trouble.

Chris and Patrick,

How have you found the top prop? Every prop inspection I wait for the " you need a new prop" report. Flying a 180 here with stock O470R.

Cheers. Rich

I had the 86 mac on mine, takeoff and climb was awesome, did slow me down a little in cruise I think, but I had big tires and bubble windows too

It’s been great so far with one glaring exception that appears to be specific to the 80” 3-blade.

There are probably hundreds of 80” Top Props running around on Bonanzas with no problems that lead long and happy lives. I’ve always been super happy with Hartzell, and between my father and me, we’ve owned lots of them, both round and scimitar blades.

But when you bolt one onto a 180/185, it’s a crapshoot whether or not you’ll have an unsolvable 1/2 order vibration. If it’s on floats, it’s almost guaranteed to shake. 206s are fine, as are other airframes, but there’s something about the 180/185 airframe/engine mount combo that often doesn’t like an 80” Hartzell. Swapping to a Seaplanes West mount will apparently also fix it, but if I’m going to spend the cash, I’d rather switch to a prop that better suits the flying I do.

I personally know of three 185s (including mine) that shake (or shook) at high RPM with an 80” Hartzell. All three already have the heavy duty mount (not the SW mount). Mine has been dynamically balanced three times (each time to within .03 ips or better) and I’ve flipped the prop 180 degrees as well. Flipping the prop helped, but it’s still unacceptable above 2400 RPM. In the cases I have first-hand knowledge of, changing props (86” McCauley or the new 86” Voyager) solved the vibration issue.

Hartzell acknowledges this, and to their credit even warns right on their product page that a new mount might be needed with the Top Prop on a 180/185.

Vibration is weird.

Hey all, I'm new here, but here's my baby. 1970 180H I've owned it for 1.5 years and have been steadily improving every little bit of it. Pretty much stock in everyway and I intent to keep it that way. Image attached.

That's a great first post!

Austin: That piece depicts EXACTLY how a Cessna 180 should live: Open, wild, and free. Congratulations on your airplane, and may you enjoy it for many years. Mine has been with me for a long time, and it is a keeper. You will find the 180 to be a true friend and faithful servant.

TN

Hi Rich. My plane has the IO520 with the 80" top prop. Mine works as advertised. I don´t notice any vibrations that Chris mentions. My plane has the sea planes west mount. Maybe that is why I don´t notice the vibration? I don´t have any before comparison because I have always flown it like it is today. I did not have any 185 experience prior to this one either.

Rgs,
Patrick.

I swear. If it don’t fly three times a week I lose my touch. Wtf. First landing was so bad. Didn’t pin it at all.

[youtube]https://youtu.be/H0tMz5zULTY[/youtube]

Thanks for the comments. I currently have a Mac C66. A couple of knots slower in the cruise isnt an issue, but its always fun, and sometimes very helpful to have better take off and climb performance. The vibration comment doesnt sound ideal. 88 blackmac, or 80 scimitar mac perhaps?

Hey all, enjoying this thread! Just got my first 185, have had and still have a pa-18 in the fleet but needed a family adventure plane. Robertson stol, turbo, wing x, rig flies great. Have the 86” Mac 2 blade now, going to change in the future just not sure what to.

Next up

So I installed my new Hartzell Voyager today.

Short version: Better in every possible metric.

Long version:
Previous prop was a round tip 80” Hartzell Top Prop. The Voyager is 86”. The Voyager blades are much thinner, and have slightly swept, squared tips.

I was hoping it would be better for short field ops, and any improvement in climb would be welcome. Seemed like a safe bet given the glowing reviews of the 86 & 88” Mac 401. Since I was going from 80 to 86”, I figured I might lose a few kts in cruise, but was willing to make the sacrifice for short field work. Previously I always planned 130 kts true, and usually saw 130-132, depending on weight. Flat out, 50 ROP I could get 137-138 true with the old prop.

Subjectively, the Voyager pulls quite a bit harder on takeoff. Climb is much, much better (on the order of 2-300 fpm at 95kts). And the cherry on top is cruise - it’s 6-8 kts faster. I ran 10 LOP at 6500, 7500, 8500, and 9500 ft. It’s a minimum of 6 kts faster at every altitude. The slowest I saw was 138 true, max was 141. It’s now the same speed LOP that it was ROP before. As a bonus, it runs cooler because of the higher speeds.

So it pulls harder, climbs better, cruises faster and is smoother to boot. If I hadn’t seen it in my own plane, I wouldn’t have believed it.

Wow Chris that is an amazing improvement... congrats. those are great numbers.