Hey everyone,
First time posting here, so go easy on me.
I’m based in South Africa and, like many of you, I’ve fallen hard for the 180/185 world. I’ve been flying a 1956 C180 for about 4 years now and absolutely love the airplane.
I eventually started wanting more power, for no good reason but STOL.
I went down the usual rabbit hole:
• P.Ponk (very seriously considered it)
• Looked into the typical 265hp setup with low-compression cylinders
• Even explored the 285–300hp route via porting/polishing
But here’s where things got tricky:
Field approvals aren’t really a thing with our regulator in South Africa. So that ruled out a lot of the common upgrade paths you guys in the US take for granted.
Once i ruled out Pponk, I started dreaming about an IO-550.
At first it felt completely unrealistic — my O-470 still had about 700 hours left, and the cost of the conversion is no joke. But things escalated quickly:
• Replaced 3 cylinders (all already near limits… painful lesson)
• Engine was getting tired, old mags, old gen….
• Then our regulator enforced the “12-year rule” even for private ops
That pretty much forced my hand. ( I told my wife we have not other choice )
So, I decided if I’m going to spend money, I’m going all in.
After a lot of back and forth, I chose the Airplains IO-550.

Current status:
• Engine has arrived
• Install is about 70–80% complete
• Now entering the fun phase: dealing with the regulator
If all goes well… I’m guessing 3 months of paperwork and inspections.

Aircraft details (before conversion):
• 1956 Cessna 180
• O-470K
• Sportsman STOL + Wing-X
• 2-blade MT

Typical cruise :
• 128–130 mph IAS @ 6,000 ft (running 850s)
• 125 mph IAS @ 6,000 ft (running 31s)
• 20inches @ 2300
• 11–12 GPH

Anyone else running a IO-550 on a early 180? Let me know!

Welcome, and congrats. That’s a good engine for sure!

FWIW… I’d seriously consider the 3B Voyager. I’ve pulled several MT’s off now in favor of the Hartzell and the perf bump is a no brainer. With that combo, you’ll see at least a 11 mph bump in cruise. It’s pretty impressive.

Only downside (besides the price) is it’s a little bit heavier.

Greg-

Thanks for showing the firewall with numerous mods from original. Nice looking plane. I have the 265 Pponk and 2B MT and happy enough with that.

The prop is a interesting one for me. As a MT owner, the comments one reads online the Voyager get seriously good rep. When doing this conversion a concern for me was putting to much weight up front with the big 550, the 2 blade MT does the job there. The aim is to keep the feel of a early 180 as much as possible. I do agree that there may be some performance to be gained having a 3 blade (MT or Voyager), but how much I guess is the big question.

To go Pponk i needed to go the route of getting a 520 core either new or overhauled, which is when the sums get bigger. There no approved shops to Pponk a 470 in South Africa so that further limited my options.

Interesting swap. I see some firewall modifications, were those for the 550 or something earlier? Specifically the gascolator location and the dish recess top center.

Do you have an exchange weight for the engines, or did you weigh the plane? I'm really curious where the CG ended up.

Should be a rocket, my 520 powered 180 runs awesome, 550 is a whole other animal.

Those mods you see are new. All have to do with the kit.

O-470k equivalent on Continentals website comes in at 425lbs (including accessories) and 550 is coming at 462lbs (including all accessories). My 470-k had a generator, where as the new 550 has a alternator, Not sure what the weight savings here will be. Also saved a small bit with the MT-2 blade.

So i am looking at around 35-40lbs more on the engine only. Then the kit will also be adding some.

She is slightly on the heavy side as 180s go, coming in at +-1750lbs before i started will all this. But she can go to 2950lbs with the wing-x at least.

MoodyMas wrote:Those mods you see are new. All have to do with the kit.

O-470k equivalent on Continentals website comes in at 425lbs (including accessories) and 550 is coming at 462lbs (including all accessories). My 470-k had a generator, where as the new 550 has a alternator, Not sure what the weight savings here will be. Also saved a small bit with the MT-2 blade.

So i am looking at around 35-40lbs more on the engine only. Then the kit will also be adding some.

She is slightly on the heavy side as 180s go, coming in at +-1750lbs before i started will all this. But she can go to 2950lbs with the wing-x at least.

I am curious how accurate the website weights are, if they are apples to apples. I was told some years ago that the crank on a 550 was 12 or 13 pounds heavier than a 520 crank, but I have heard lots of people say that a 550 and a 520 are direct replacements with no change in W&B. I have seen a couple early 180's with 550's, IIRC they had a very far forward CG. That really what I am most curious about, a real number, not a talking at a flyin number.

Well as soon as W&B is done I will keep you posted! Lets see what comes from it.