I’m thinking of getting a set of 6.00-6 tires, and a different prop for my 185 to make it go faster.

I currently have an IO-550 and McCauley 401 prop.

In the winter, it would be nice if it were faster for those long trips when I don’t have access to a Cirrus.

Since props and tires are easy and quick to change, I was thinking of starting there. I would obviously put the 401 back on for float season.

What could I expect for speed differences between props? I’m assuming whatever the shortest aluminum two-blade prop that is approved would be my best bet?

Thanks!

I'd bet on a 2 blade MT being faster then an aluminium.

On a Cirrus, the two aluminum props available are faster than the two MT’s available and the two composite Hartzells, which is why I assumed that.

I’m half tempted to put an experimental C of A on it and bolt an SR22 prop on and see how it does. (Assuming the hub length is the same)

Ross4289 wrote:On a Cirrus, the two aluminum props available are faster than the two MT’s available and the two composite Hartzells, which is why I assumed that.

I’m half tempted to put an experimental C of A on it and bolt an SR22 prop on and see how it does. (Assuming the hub length is the same)

That's very interesting. I've always thought that was one of the marketed advantage of the MT.
If the hub length was the same, noone would probably even notice if a SR22 prop ended up on it for a few test flights.

Ill measure the hubs and see if it would fit.

A buddy of mine just changed out his 2 blade for a voyager, I’ll chase hime down and see about trying his two blade also.

I had a 74 180j early 90,s put a pponk 520 in from Stevie before he had stc. Was put in on field approval in canada. Put on a c90 3 blade same as 403 thread less. That was a fast 180 . When he got stc flew down he put on a 86 401. Slowed plane down 6 to 8 kts. Really like the c90 super smooth on stock mount. Now have a 180 k 520 84 hartzel not as fast or as smooth even with seaplanes west mount. I also tried my 90 in 204 prop on 520 it was fast same as c90.4000 ft standard day indicated 170 mph in the yellow. Was in a 53 180 called wheat rocket owned by nick mardes. 550 all speed mods u could get even tail wheel had fairing.easily go 200 mph.was a wild ride can’t remember prop but I know was not mt.

Take the old standard 86” prop, overhaul it and during overhaul cut the blades down to 82”. Performance will suffer but speed will increase.

G44 wrote:Take the old standard 86” prop, overhaul it and during overhaul cut the blades down to 82”. Performance will suffer but speed will increase.

Isn't an increase in speed considered an increase in performance???

C180_guy wrote:

G44 wrote:Take the old standard 86” prop, overhaul it and during overhaul cut the blades down to 82”. Performance will suffer but speed will increase.

Isn't an increase in speed considered an increase in performance???

Yes, however since most on this board equate performance to short field STOL operations only I made the statement I made to fit the group.

Kurt

I’ve only dabbled in the prop optimizing game, but have seemed to find top end speed to be a case of diminishing returns in a couple planes. And for my purposes, not worth changing props for.

Unlike the bottom end / climb, there I found improvements worth changing expensive components for. I also went to a 88” 401 on my 185 (520) this winter, and I was very impressed. What I really wanted was a Voyager, but a forum member connected my need to another‘s and I ended up with a freshly overhauled 401 at a significant cost savings.

It was faster in cruise than I expected for a “Holeshot” prop (146kts at 24 square, 5200’ in winter conditions). It can comfortably hold 140kts at a pretty economical cruise, which in my world is pretty fast, and can fly right at maximum structural cruise speed if you want to. With a 550 and the same prop I imagine you can beat my 520 handily too.

I think you may find you get as much speed on the top end from wheel pants and gear leg fairings if not already equipped, and cleaning up the airframe a bit as you do from a prop change. This said, you’re probably able to buy a new prop without the financial worry I would have, and it’s fun to see results from changes and do the plane Lego game.

If you change it, would love to hear the results.

Thanks guys. I inquired about a 2 blade McCauley that is for sale today and it turns out the guy switched to a Hartzell Voyager and it was no slower than the 2 blade.

Maybe I should just buck up and buy one of those and sell my 401. Sounds like best of both worlds.

Ross4289 wrote:Thanks guys. I inquired about a 2 blade McCauley that is for sale today and it turns out the guy switched to a Hartzell Voyager and it was no slower than the 2 blade.

Maybe I should just buck up and buy one of those and sell my 401. Sounds like best of both worlds.

I would.

Everything I have read (online) and heard (online) regarding the Hartzell Voyager prop makes me think this best engineered prop for the Skywagon. It is always a hard comparison when someone takes an old end of life prop and puts a nice brand new prop out front and reports performance gains in cruise, climb and TO/Landing distance but it just seems there are too many anecdotal positive reports from many reliable skywagon owners. They are also seem to be fairing well in terms of maintenance issues and ADs - time will tell on this one. I believe the prop is 77 lbs which is similar to other 86 inch 3 blade props. The 2 blade MT has the advantage of a significant weight savings on the nose beneficial CG. I like the simplicity of Aluminum. I have had a 78 inch Hartzell for the last 15 years that is still running strong but I will be looking at the Voyager in the future for sure. Here is a nice review:


https://hartzellprop.com/cessna-skywago ... propeller/


Josh

Anyone want to lend me a Voyager to try on my 206? I'll be comparing it against a new 3 Blade Mac, so it'll be a fair comparison... haha.

If you believe these data the MT 2 blade hauls ass:

https://www.mcfarlaneaviation.com/media ... esults.pdf

What is the smallest 2 blade approved for a185f with 520D that does not require governor restricted RPM below 2850? Yes, I am aware of all the tests showing thrust at lower RPM is as good maybe superior.

Cub180 wrote:I also tried my 90 in 204 prop on 520 it was fast same as c90.4000 ft standard day indicated 170 mph in the yellow.

This is a combo that intrigues me. I remember hearing that a bunch of Canadians loved this setup on 185s on floats. I've never been able to track down one to try. I prefer the look of the 2 blade parked on the ramp, and the weight savings over a 3 blade would be cool. I bet it would BARK at 2850 though.

Was in a 53 180 called wheat rocket owned by nick mardes. 550 all speed mods u could get even tail wheel had fairing.easily go 200 mph.was a wild ride can’t remember prop but I know was not mt.

Nick is a buddy of mine. NOBODY knows more about making a 180 fast. I got to fly his 180 back in 2003 when it still had the massaged IO-520 in it. It is ridiculous how fast it is and it has only gotten better since then. He has a Mac 401 that has been massaged a bit as well.

"Life is short, fly fast" - Nick Mardis

frstnflt wrote:If you believe these data the MT 2 blade hauls ass:

https://www.mcfarlaneaviation.com/media ... esults.pdf

What is the smallest 2 blade approved for a185f with 520D that does not require governor restricted RPM below 2850? Yes, I am aware of all the tests showing thrust at lower RPM is as good maybe superior.

The original 2 blade was approved down to 82". It was a threaded prop which is no longer supported by Mac. There is a Cessna service kit to put a modern treadless 2 blade on it, a C230 IIRC. The service kit specifies an 82" prop though, which I'd rather not go that short, so I've explored pursuing an FA with the 230 at 86", which is an approved combo on the prop TCDS. I don't NEED a prop so I haven't moved on it yet.

FWIW, I had a worn out 86" C58 2 blade. I horse traded for an 86" C401 3 blade.

The 401 is awesome out of the hole and climbing up to around 8K. Cruise up to this point was comparable to the 2 blade. Above 8K it starts to fall on its face and the 2 blade will outperform it.

I spoke to a guy who flew climbers out of Talkeetna to the glaciers. He said they were always heavy and had to climb to 12 to get up there. The boss installed the 401 and his experience echoed mine. His squawked enough the boss put the 2 blade back on.

I'm based at 5500'. I get to 12-14 regularly going west and in the summer when I have the pod on, heavy, and hot out, the 401 was disappointing crossing the hills headed to ID. I pulled it off and put the 2 blade back on. I get off as short as I want but I like to go fast.

FOR SALE, 86" mac 401. 0 Since overhaul. $9K

Okay, I’ll just go ahead and say it: 185s aren’t for going fast.



MTV

mtv wrote:Okay, I’ll just go ahead and say it: 185s aren’t for going fast.



MTV

This was my takeaway, so I have a half share of a much faster plane for when I feel like doing 200kts cross country, in which I can fit one passenger and their purse and toiletries. The 185’s for when I want to bring a good deal of things or people with me off the grid, and it’s admirably purpose built.

This said, I can respect guys wanting to room and board one plane and do it all with it. If there is one to do it all, being haul three quarters of a ton at a respectable speed over a respectable distance for dry footed aviators, it’s probably the 185. It’s even more endeared to us in the soggy side of aviating.

As for speed on wheels I just wouldn’t want to change props seasonally but I have to watch my budget closer than many 185 owners to justify the ownership to the Mrs. I have to split my finances and attentions between two, and often wonder if it’s the wisest path. Fortunately this concern completely negates thoughts of owning more than one propeller and changing between them.

If I was looking to optimize cruise, I’d probably go to the Voyager too. Seems to nip the issue of multiple props in the bud, but for my purposes the 88” 401 has been very, very impressive and stopped my drooling on my tablet with the Hartzell site up.