• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Cessna 180 engine options

No alcohol or methanol. I understand that the use of methanol treated fuel is not allowed in any of the car gas STC's. I'm under the belief that is the main culprit in the delamination of fuel bladders.
 
On 850s with 8” tailwheel I got 180+ mph at 1000’ msl when breaking my engine in. I haven’t been on small tires since but with 29” mains and BBW I can get 150 mph if I want to. 24/2400 gets low 140s. Definitely faster than it was with the 470.
 
No alcohol or methanol. I understand that the use of methanol treated fuel is not allowed in any of the car gas STC's. I'm under the belief that is the main culprit in the delamination of fuel bladders.

We don’t have ethanol in gasoline in Ak. Never have. We used to have MTBE for a couple of winters but that was 20 years ago.
 
So bottom line, for me, the advantages of a ponk conversion are outweighed by the down sides.

Well said. Your operation has clearly defined your logical powerplant choice. Have you had any issues with mogas effecting your bladder tanks? I suspect the lower compression of the STC'd PPonk would allow it to run OK on mogas ......

I've owned this 180 for about 8 years,
and have run it on mogas the whole time--
80% mogas / 20% 100LL until fuel prices got so high,
and pretty much 100% mogas since then--except on trips when mogas isn't available.
The previous owner had it for about 15 years and I believe he ran it mostly on mogas also.
No bladder issues.

Yes, the Ponk engines are (i think) 7.5:1 compression instead of the stock 7:1,
I know people who run mogas in them with no problems.
However, as far as I know, mogas isn't approved for use in this engine by the engine STC or by a separate STC.
Running unapproved fuel is like flying out of annual, or without a medical, or without a current flight review--
everything is fine until it isn't.
I don't want to have a mishap one day & have my insurance refuse to cover any damage because of unapproved fuel.
I'd like to see EAA or Petersen add the ponk engine to their mogas stc's, or have Northpoint add it to the engine stc,
but I doubt either of those things is gonna happen.
 
I’ve moved onto a Super Cub but owned a 180 for a bit and flew another 180 with a Pponk engine.

My 180 was a 1954. I ended up putting a heavy case O470R on it with a Mac seaplane prop along with Leading Edge exhaust. I was very happy with it. I did formation take off with my friend in his 1953 with a J engine and would walk away from him on takeoff and climb.

The 180 that I flew with a Pponk might have been a 1955 I don’t recall. It also had a seaplane prop on it along with a Snider speed mod. It was very fast. Into the yellow arc around 23 squared.

For tooling around on my own time I would prefer my old 180. If I was working the airplane I would’ve preferred the Pponk 180.
 
Upping engine displacement in a 180 isn’t much different than doing it in a Cub. The biggest advantage is rate of climb and the heavier the plane the bigger the advantage. Since my primary mission was flying family and friends to and from a 1000’ strip with 100’ trees on the end, additional clearance over those trees in unfavorable winds was what I was looking for.

I’ve told this story before but the first time my wife rode in the plane after the Pponk-C401 3-blade upgrade we weren’t even at 1000’ off of Lake Hood strip yet and she said that was the best money I’d ever spent on an airplane. And to further qualify, the Pponk replaced a 100 hour factory reman and 88” seaplane prop, so not a weak or worn out engine. There’s no replacement for displacement.
 
In an old thread Dave Calkins mentioned running a 90" McCauley C2A34C204 on his 180, I'm interested in the pull gained over an 88" McCauley 203. How much did the low pitch stop have to be changed to get the 90" to swing at 2600 rpm?
 
In an old thread Dave Calkins mentioned running a 90" McCauley C2A34C204 on his 180, I'm interested in the pull gained over an 88" McCauley 203. How much did the low pitch stop have to be changed to get the 90" to swing at 2600 rpm?
That's for a 2400 rpm engine. Low pitch 15.0* High pitch 29,4*

Propeller and 1. McCauley constant speed propeller (threadless) (landplane, skiplane) Propeller Limits (a) Hub C2A34C204, blade 90DCB-8 Diameter: not over 82 in., not under 80.5 in. Pitch settings at 30 in. sta.: Low 15.0°, high 29.4°

https://drs.faa.gov/browse/doctypeDetails?modalOpened=true
 
In an old thread Dave Calkins mentioned running a 90" McCauley C2A34C204 on his 180, I'm interested in the pull gained over an 88" McCauley 203. How much did the low pitch stop have to be changed to get the 90" to swing at 2600 rpm?

I’d imagine it was little if any. Like an 86” vs 88”. I remember Steve Knopp testing the C401 in both lengths and finding no thrust difference. As he said, the only thing the 2” did was make noise.
 
I know other guys with 180K and the O-470-U have changed the pitch stop to allow that engine to spin up to 2600 with the 90". I'm just curious how much the low stop has to be changed.
 
Upping engine displacement in a 180 isn’t much different than doing it in a Cub. The biggest advantage is rate of climb and the heavier the plane the bigger the advantage. Since my primary mission was flying family and friends to and from a 1000’ strip with 100’ trees on the end, additional clearance over those trees in unfavorable winds was what I was looking for.

I’ve told this story before but the first time my wife rode in the plane after the Pponk-C401 3-blade upgrade we weren’t even at 1000’ off of Lake Hood strip yet and she said that was the best money I’d ever spent on an airplane. And to further qualify, the Pponk replaced a 100 hour factory reman and 88” seaplane prop, so not a weak or worn out engine. There’s no replacement for displacement.

It's also, very noticeable in takeoff distance on floats. And, as you point out, even more noticeable when you're heavy. Haven't tried it but I bet it would fly hundreds of pounds over gross where I suspect with the O-470 it wouldn't get on step (which is actually a safety benefit making it impossible for someone to fly with a stupid load).

It's still noticeable when light though. Most of the aircraft based on our lake are Cub's. When the 180's light (me and about half tanks) I break water in about the same place they do. I'm pretty sure it climbs better as well. Then I get to cruise at 142 MPH. I just pay for it with fuel.
 
I know other guys with 180K and the O-470-U have changed the pitch stop to allow that engine to spin up to 2600 with the 90". I'm just curious how much the low stop has to be changed.

Pitch stop? Can’t they achieve RPM by adjusting the governor? My pitch stops are set properly per spec and I know I can make it spin 2900 because it did it one summer. Everyone knew my plane without looking, because of the noise. It sure did perform well. Dial yours up to 2700 and you’ll gain more than 2” of prop can provide.
 
Haven't tried it but I bet it would fly hundreds of pounds over gross where I suspect with the O-470 it wouldn't get on step (which is actually a safety benefit making it impossible for someone to fly with a stupid load).

Never underestimate the raw skills of pilots doing stupid things in aircraft, you might be surprised.

MTV
 
Depends more on the floats than the engine. At 3190# a 470 works but a 520 works better.
Back in the 90's I flew a 206 down to Wipline for refurbishing, installation of their copilot door, 4000 amphibs and an IO-550. They told me during flight testing they were able to get their testbed 206, with 4000 straight floats, in the air with such a load they were unable to fly it out of ground effect. We latter installed Wip 4000 straight floats on our 206 and were amazed at the ability of that aircraft to climb up on step when HEAVY, something the 3430's would never do. The takeoff run was amazingly long. We joked you needed a Six Pack License to carry five passengers in that airplane (speed boat).
 
Last edited:
Back in the 90's I flew a 206 down to Wipline for refurbishing, installation of their copilot door, 4000 amphibs and an IO-550. They told me during flight testing they were able to get their testbed 206, with 4000 straight floats, in the air with such a load they were unable to fly it out of ground effect. We latter installed Wip 4000 straight floats on our 206 and were amazed at the ability of that aircraft to climb up on step when HEAVY, something the 3430's would never do. The takeoff run was amazingly long. We joked you needed a Six Pack License to carry five passengers in that airplane (speed boat).

Actually, those floats will fly out of the water nicely at 3800. I flew 185s at 3350 on late PeeKay 3500s, and EDO 3430s out of the Fairbanks float pond. Then I was handed the keys to an IO 550 206 on Wip 4000 straight floats. I cursed them for a while, till I figured out to get them to fly….on the step, a hard shove on a rudder, and the thing would come unstuck. Felt awkward, but after a few more trials, that thing would come out of the water at 3800 pounds all up, within a 100 feet or a little more of where those 185s launched, at 3350. And it’d climb away.

A great working airplane, that one.

MTV
 
Actually, those floats will fly out of the water nicely at 3800. I flew 185s at 3350 on late PeeKay 3500s, and EDO 3430s out of the Fairbanks float pond. Then I was handed the keys to an IO 550 206 on Wip 4000 straight floats. I cursed them for a while, till I figured out to get them to fly….on the step, a hard shove on a rudder, and the thing would come unstuck. Felt awkward, but after a few more trials, that thing would come out of the water at 3800 pounds all up, within a 100 feet or a little more of where those 185s launched, at 3350. And it’d climb away.

A great working airplane, that one.

MTV

Taking the thread a little off topic but I loved the way those 4000's step turned. Felt like you were sitting in your Lazy Boy back home. My CAP's are scarry.
 
Back
Top