I have an 80" Round tip Hartzell three blade on my 185 (PHC-C3YF-1RF w/F8468A -6 blades). It works fine, and has less than three hundred hours since new (came on the plane when I bought it last year), but I know it's not the best prop for what I typically do with the airplane.

I do just enough backcountry flying in Utah and Idaho that I'm exploring an 86" Mac 401, but I can't find any first-hand accounts from those who have made this (or a similar) switch. I've spent a rediculous amount of time researching this, but every account I've gotten either in print or in person has quoted marketing crap that I have no interest in. I'd like honest, first hand accounts by those who've flown them.

I might consider a larger Hartzell scimitar, but I don't know if those have the low end grunt of the 401.

Specifically, I'm curious how much of a difference I'll see on takeoff and initial climb with a 401, and what penalty I'll take in cruise to decide if it's worth pursuing. Engine is the stock IO-520D. Someday when the engine is due, I'll go with a 550, but ideally that is way in the future. I already have a Sportsman coming.

My Hartzell is new enough that I figure I can offset a significant part of the purchase, but if the performance difference is negligible, there's no point.

I typically see 128KTAS LOP and 135KTAS ROP at altitude. Not a speed demon, but it gets the job done. I'd gladly give up a few kts if the bottom end was Holy-crap better, but I also know how subjective this can be.

I'm undecided on the MT, as I've seen a brand new one crack the nickel leading edge and want something that just works. It's not like I need the weight savings, as I can't put it over gross as it is.

I have and like the MT, on an IO-550 but it has an RPM restriction. 2700. 2850 from your IO-520 is a no go.

Steve Knopp has a propeller page on his web site that includes a tip speed calculator. Essentially, he makes a case for not turning your propeller so that the tip speed exceeds 93% of the speed of sound.

http://pponk.com/props/#1463774934977-1d7f57b4-6b2b

There is some really good thrust data there too if you study through his pages. His honesty is pretty evident after you read it all. Not just a bunch of marketing.

When I had Steve Knopp rebuild my IO550, I asked him if I should replace my Hartzell with a Mac 401. He told me to save my money. He said that while the 401 would give me maybe a small amount more low speed dig out of the hole, it would be more choppier and slower on the top end. His opinion was the round tip Hartzell was real smooth. So, I had it overhauled because it had lived in SE Alaska for its first 500 Hrs. Blades were almost like new. Still going strong. - my 2cents....

I spoke with Steve Knopp extensively a few years ago about the best backcountry propellor for a IO520D 185. We discussed all the current props available including the Hartzell Scimitar. Just as RockHopper reported Steve had the 86" Mac 3-blade performing better off the ground as well as "braking" on landing. He said the Hartzell or the MT would be a bit faster in lower altitude cruise, but at high altitude the long Mac's would be faster then the shorter 3-blades.

Willie Stene prefers the 86" or 88" Mac 3-blade on his wagons (he has one of each). A guy I know who has a IO550D in his 185 had a Hartzell wide cord 3-blade initially but changed to an 88" Mac 3-blade and said the difference is night and day.

Guess it all comes down to how aggressive you want to fly your 185 in the backcountry, and how much money you want to spend achieving it.

The only experience I have to date with an IO520D 185 is with the 2-blade 86" Mac so can't speak personally to its comparison.

Thanks, guys.

My Hartzell is very smooth below 2500 rpm, less so above that. Dynamic balance made no difference, as it was already very good according to the Dynavibe or whatever machine he used.

I'm sure the Sportsman will make a sizeable difference, so I'll probably wait until I get that done. As it is, I've been into Dirty Devil (1100' I think) and I probably won't go anywhere much shorter, so at this point I'm just looking at increasing my margins. The airplane can land much shorter than it can takeoff, and I'd love to even those out a bit. I just wish I had a bit more pull on the low end, as I never quite seem to have as much as I'd like. Guess that'll never change no matter what I do...

Edit: Just reread what you said about high vs low altitude cruise. Very interesting - seems almost ideal, as down low I don't care about speed, but when I'm going places I'm always 8500' or higher.

I called a guy who was selling his Mac 403 on Barnstormers (he bought a 401) hoping to get a first hand account, but he never called back.

Cannon,

Just a thought: Your avatar says you are based in “SoCal”. If that represents Southern California, and maybe if it doesn’t, pay attention to the noise signature of those very long propellers. Easy to make enemies with an 86 or 88 inch prop running at 2850.

MTV

Agreed, though I'm based out of Santa Paula which is fairly airplane friendly. Nevertheless, I'm very aware of the noise, so even with the 80" I usually use 2700 for takeoff unless I have a load on board.

Ah Santa Paula. It's 1982 I think. I've been taking aerobatic instruction in a 150 Aerobat from some guy in Oxnard who was too old to fly combat in WW2 so became an instructor. Anyway I'm ready to fly something like a Citabria or a Christian Eagle, neither of which was at Oxnard. I head over to Santa Paula one weekend and I'm walking the hangar line looking for an instructor with said aircraft. I come across an open hangar with a Christian Eagle parked out front. A guy is in the hangar sitting behind his desk. He invites me in, I sit down and explain what I'm looking for. He gives me a price, I don't know maybe a $100 per hour which I can in no way afford. We talk a bit and share introductions. Even then I have no idea who this guy is but I notice a picture sitting atop his desk. It's of a helicopter at the top of a loop. I'd never seen a picture like that before. I was sure this was the guy I wanted to take instruction from, but I just couldn't afford it. Of course looking back I wish I could have figured out a way. Oh, the guys name? Sammy Mason.

Cannon wrote: I have an 80" Round tip Hartzell three blade on my 185 (PHC-C3YF-1RF w/F8468A -6 blades). It works fine, and has less than three hundred hours since new (came on the plane when I bought it last year), but I know it's not the best prop for what I typically do with the airplane. .....

Your Hartzell has different (shorter) blades, so maybe/probably not applicable,
but it sounds like there is an rpm limitation on the 82" & 84" props that Knopp sells.

From his website:
" Hartzell Propellers for Cessna 180 and 182 Models
Our STC SA02278AK approves installation of the Hartzell PHC-C3YF-1RF/F8068 and PHC-G3YF-1RF/F8068 Propellers (82” and 84” lengths)......Note - for Cessna 185 owners: We did not include the Cessna 185 under our STC because the stock Cessna 185 with the Cont. IO-520-D engine turns 2850 RPM. The Hartzell propeller model we offer is limited to 2700 RPM"

http://pponk.com/props/

Re MT porops, I can't see installing a prop that's limited to 2700rpm on an engine that's redlined at 2850.
When noise is an issue, and performance isn't, you can always dial it down,
but I'd sure want all the horsepower available when I was in a tight spot.

Barnstormer wrote:Ah Santa Paula. It's 1982 I think...... I was sure this was the guy I wanted to take instruction from, but I just couldn't afford it. Of course looking back I wish I could have figured out a way. Oh, the guys name? Sammy Mason.

Yup, that's one of those missed opportunities for sure. His son and grandson are still there.

Still one of the best airports in the country. I may be biased, but it is .

If I do change props, it needs to be compatible with both the 520 and 550. Seems like most that are ok in the 520 are good on the 550, but the opposite is often not the case because of the 2850 limit on the 520. I've yet to hear anything bad about the 401, I just don't know if the difference is worth it or not.

If you haven't already done so you might try improving performance in less expensive ways first. Such as do your 185 have a Brackett air filter or the K&N type (can't recall the name)? How about shedding excess weight? Still have the big battery in the back? Replace it with an Odyssey or something even lighter. Do you carry a tool kit or survival bag? Can you lighten anything in those? Titanium gear legs? Okay those are the cost of a prop. Old avionics in the panel that you don't need? Hopefully your plane doesn't have flap gap seals, if it does loose them. Replace the massive electrode spark plugs with Iridiums. Replace one of the magnetos with electronic ignition. Okay that's a third of a propellor. Anyway, some thoughts.

Cannon wrote:

Barnstormer wrote:Ah Santa Paula. It's 1982 I think...... I was sure this was the guy I wanted to take instruction from, but I just couldn't afford it. Of course looking back I wish I could have figured out a way. Oh, the guys name? Sammy Mason.

Yup, that's one of those missed opportunities for sure. His son and grandson are still there.

Still one of the best airports in the country. I may be biased, but it is .

I have to agree. Have been through a few times for various ratings, have met some of the lcoal legends, including the Mason clan. If I end up back down that way, I will give you a shout.

Barnstormer wrote: Ah Santa Paula. It's 1982 I think.......

I just saw a TV documentary about Steve McQueen.
I'd read somewhere he was an avid pilot, but I guess he didn't take it up until 1978 or 79.
Lived on the Santa Paula airport in a hangar in 1979 while his local ranch house was being worked on, flew a Stearman.
Unfortunately he died of cancer in 1980.

hotrod180 wrote:

Barnstormer wrote: Ah Santa Paula. It's 1982 I think.......

I just saw a TV documentary about Steve McQueen.
I'd read somewhere he was an avid pilot, but I guess he didn't take it up until 1978 or 79.
Lived on the Santa Paula airport in a hangar in 1979 while his local ranch house was being worked on, flew a Stearman.
Unfortunately he died of cancer in 1980.

And guess who taught him aerobatics? Yep, Sammy Mason. Pretty cool.

Barnstormer wrote:If you haven't already done so you might try improving performance in less expensive ways first. Such as do your 185 have a Brackett air filter or the K&N type (can't recall the name)? How about shedding excess weight? Still have the big battery in the back? Replace it with an Odyssey or something even lighter. Do you carry a tool kit or survival bag? Can you lighten anything in those? Titanium gear legs? Okay those are the cost of a prop. Old avionics in the panel that you don't need? Hopefully your plane doesn't have flap gap seals, if it does loose them. Replace the massive electrode spark plugs with Iridiums. Replace one of the magnetos with electronic ignition. Okay that's a third of a propellor. Anyway, some thoughts.

Make sure if you replace your spark plugs you install Tempest and NOT Champion's. Massive electrode or fine wire.

Thanks. I know about the Champion debacle and put Tempest plugs in my previous 180. Champion quietly fixed their design issue a year or two ago since Tempest was killing them.

My airplane will never be a featherweight. It has a very nice panel that I plan to keep, so the only 'easy' weight savings are interior and battery. The battery is not even 2 years old, but when it goes I'll probably do an Odyssey on the firewall like I did on my 180. That's worth 15lbs or so. My wife loves the plane as-is, so going with a utility interior is probably not in the cards. Hence the Sportsman and possible prop change.

I'd honestly never thought about a filter. Any first hand accounts from those who have swapped to a K&N style? What kind of MP difference are we talking on takeoff? I already get 29" pretty reliably at sea level (taken from the EI data), so the Brackett isn't doing too bad.

Cannon wrote:I have an 80" Round tip Hartzell three blade on my 185 (PHC-C3YF-1RF w/F8468A -6 blades). It works fine, and has less than three hundred hours since new (came on the plane when I bought it last year), but I know it's not the best prop for what I typically do with the airplane.

I do just enough backcountry flying in Utah and Idaho that I'm exploring an 86" Mac 401, but I can't find any first-hand accounts from those who have made this (or a similar) switch. I've spent a rediculous amount of time researching this, but every account I've gotten either in print or in person has quoted marketing crap that I have no interest in. I'd like honest, first hand accounts by those who've flown them.

I had the same prop as you when my 185F (IO520) was on wheels, it worked fine for where it was operating, but when I changed over to floats, it just didn't cut it. I ran the plane the first season with the 80" Hartzell, then put a new 401-86" on that winter, next spring when back on the water, there was a significant improvement out of the hole as compared to the Hartzell, a good thing when operating out of small lakes. As far as top end speed, I really don't know, most of my trips are an hour or less at moose siting levels, where speed is not an issue. It is more noisy, everyone knows from a few miles away whose plane is out there, a distinctive sound. It was a good investment for how I use the plane, when it is time for a new engine we will have to reanalyze to see what is available and works well with a 550. If speed is your greater concern and if prop noise could be an issue, this may not be the prop for you, but if getting off the ground quicker than you do now is the goal, then this prop may be worth considering.

Steve

Steve

Cannon wrote:Thanks. I know about the Champion debacle and put Tempest plugs in my previous 180. Champion quietly fixed their design issue a year or two ago since Tempest was killing them.

My airplane will never be a featherweight. It has a very nice panel that I plan to keep, so the only 'easy' weight savings are interior and battery. The battery is not even 2 years old, but when it goes I'll probably do an Odyssey on the firewall like I did on my 180. That's worth 15lbs or so. My wife loves the plane as-is, so going with a utility interior is probably not in the cards. Hence the Sportsman and possible prop change.

I'd honestly never thought about a filter. Any first hand accounts from those who have swapped to a K&N style? What kind of MP difference are we talking on takeoff? I already get 29" pretty reliably at sea level (taken from the EI data), so the Brackett isn't doing too bad.

Going to a challenger or Donaldson paper filter will get you another 1" of MP over the brackett. I like the Donaldson filters myself.

What is involved in switching from Brackett to Donaldson on a Cessna 180? Do you need a different housing for the Donaldson, and where would you get it?

7GC wrote:What is involved in switching from Brackett to Donaldson on a Cessna 180? Do you need a different housing for the Donaldson, and where would you get it?

The Donaldson filter comes in the housing. If you still have the original 1/4 turn fasteners then it's very easy. Other wise you need to pull the fasteners out of the new filter and use long screws. Either way it's a pretty quick install. The filters are good for 500hrs, just blow them out at annual.