Cessna 182P - Pponk my O-470 or IO550?

robertb

robertb

Pre-takeoff checklist
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robertb
Hello,
I have been thinking about an engine overhaul for a few years and may be getting closer to actually doing the deed. Our O-470 has treated us well but I expect the time to overhaul is on the horizon.

I have considered the benefits of the Pponk (now called the Northpoint XP470) vs. cost. A friend recently mentioned doing an AirPlains IO550 conversion. We will likely be keeping the plane for quite a few more years. The airframe is about 4,500hrs and in pretty good shape. The panel will be needing a little love in the coming years as it has a GNS530W, an Aspen 1000 pfd, S-Tex 60-2, and no engine monitor. It's a solid plane and only occasionally are we pushing it's limits. But, we have curtailed some of our plane camping as the performance when loaded reduces safety margins to a pretty thin level.

Let's say that cost is a minor factor in the big picture as I will hopefully amortize the engine upgrade expense through the next 15+/- years of flying. My wife has a disability which pretty much requires a high-wing aircraft. A fancy new bird would be nice but I haven't found a plane easily accessible for my wife. She loves two doors and her mobility will restrict us to a high-wing aircraft.

Perhaps the first question I will get is "What problem are you trying to solve?" I need to make some cash disapear. ;)

If anybody has first hand knowledge of these options, I'd love to hear some thoughts.
 
If you’re ok with the greater fuel burn, why not? Shorter TOs, faster cruise.

Can you do an IO-470 for 260 hp? I have that in my 1976 182P.
 
An IO-550 is a big expense. Pponking it will be the better dollar/hp value. In either case it’s the prop that does the magic so include that in your cost estimate.
 
Are you unhappy with the 470? If you give up the 470 you give up the Mogas option. I flew a 520 powered 182 in FL, and it was like why? Ya it gets off the ground quicker and climbs faster but isn’t really much faster. Might be more useful for you in San Diego.
 
I have owned a 1974 182P that I had overhauled to a P.Ponk. I've also owned a 1973 182P that the previous owner upgraded to an AirPlains IO-520.

I've been reading airplane forums for decades. My opinion is generally not widely held from what I've read. For me, the ultimate plane is a 182P with a P.Ponk (now Northpoint) and a 2 blade MT prop. I now have a nice SR22 because my wife likes it better than the 182. For me I preferred the 182. The SR22 is a very nice consolation prize though.

For me:
The ultimate roomy reliable stable plane is the P.Ponk 182. Mine would do between 140-145 KTAS (verified by 3 leg GPS test). Incredible useful load and stone simple. The only thing better would be one with the Peterson canard.

Most prefer Injected, but not for me. The Northpoint (P.Ponk) uses gravity, not an electric fuel pump. My IO-520 returned unused fuel to the right tank (if I remember correctly), so I couldn't set the fuel selector on "both" and fly along.

The P.Ponk overhaul when I did it was about the same price as a normal overhaul so an incredible value.

All that said, the IO-550 is a very nice upgrade. Whether it's worth the cost is a decision left up to the owner.
 
manac said:
Are you unhappy with the 470? If you give up the 470 you give up the Mogas option. I flew a 520 powered 182 in FL, and it was like why? Ya it gets off the ground quicker and climbs faster but isn’t really much faster. Might be more useful for you in San Diego.
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With some of our adventures, the climb/take-off performance has left us with pretty thin margins. (Mexican Mountain, UT, with camping gear is the most notable example.) We do find ourselves at max gross enough that the departure performance improvement would nice. Cruise speed... well, I pull the throttle back in cruise that speed has never really been a big deal to me. Your comment about San Diego is a valid one too which I hadn't give much thought. We do have some pretty good hills around here and increased rate of climb never hurts. Thanks for you thoughts and insight!
 
szwinger said:
I have owned a 1974 182P that I had overhauled to a P.Ponk. I've also owned a 1973 182P that the previous owner upgraded to an AirPlains IO-520.

I've been reading airplane forums for decades. My opinion is generally not widely held from what I've read. For me, the ultimate plane is a 182P with a P.Ponk (now Northpoint) and a 2 blade MT prop. I now have a nice SR22 because my wife likes it better than the 182. For me I preferred the 182. The SR22 is a very nice consolation prize though.

For me:
The ultimate roomy reliable stable plane is the P.Ponk 182. Mine would do between 140-145 KTAS (verified by 3 leg GPS test). Incredible useful load and stone simple. The only thing better would be one with the Peterson canard.

Most prefer Injected, but not for me. The Northpoint (P.Ponk) uses gravity, not an electric fuel pump. My IO-520 returned unused fuel to the right tank (if I remember correctly), so I couldn't set the fuel selector on "both" and fly along.

The P.Ponk overhaul when I did it was about the same price as a normal overhaul so an incredible value.

All that said, the IO-550 is a very nice upgrade. Whether it's worth the cost is a decision left up to the owner.
Click to expand...
Ok. Now that's some great info! I don't think the canard modification is in our future but I appreciate the honest thoughts and support for the p.ponk. My gut told me to go that direction and I suspect it will be the chosen path. The only difference may be the 3 vs. 2 blade prop. We go into dirt strips often enough that the improved ground clearance could be a benefit. I don't understand how we manage to chew up the leading edge of our current 2 blade prop as I do everything I know to avoid grabbing rocks and debris.
Thanks for the impressions you shared!
 
As a 182P owner who has had both the 3 blade hartzell Top Prop and presently a MT 2 blade; The Hartzell was significantly quieter. No 2 blade Womp Womp sound impact. The 3 blade kind of purred along and less fatiguing. The lower cowl is easier to remove with the 2 blade.
 
NordicDave said:
As a 182P owner who has had both the 3 blade hartzell Top Prop and presently a MT 2 blade; The Hartzell was significantly quieter. No 2 blade Womp Womp sound impact. The 3 blade kind of purred along and less fatiguing. The lower cowl is easier to remove with the 2 blade.
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Good info. Thanks Dave!
 
NordicDave said:
As a 182P owner who has had both the 3 blade hartzell Top Prop and presently a MT 2 blade; The Hartzell was significantly quieter. No 2 blade Womp Womp sound impact. The 3 blade kind of purred along and less fatiguing. The lower cowl is easier to remove with the 2 blade.
Click to expand...
My original 182 had the Hartzell Scimitar prop when the engine was O/H'ed. I switched to the 2 blade MT. It was significantly lighter which helps the nose heavy 182. It was also a bit faster. Seemed to like to run 2450 RPM.

My 182 with the IO520 came with an older 3 blade Hartzel. I changed that to a 3 blade MT prop, then to a 2 blade MT prop.

From what I've read, most people prefer a 3 blade. I think it's a good option. I just like 2 blade for the reduced weight and ease of maintenance (both cowl access and shipping options). Even the MT people will recommend the 3 blade prop which is why I put one on the IO520. I'm just odd. I swapped it for a 2 blade. The blade length is the same on the MT 2 blade vs 3 blade. Some 3 blade props have shorter blades the their 2 blade counterparts.

I'm just stating this for a data point. I read all the posts that I could choosing props for a 182 when I purchased mine. I think most people are happier with a 3 blade (and a fuel injected engine vs carb). One other point that may have helped form my opinion. I flew mostly 7,500 - 9,500 MSL depending on direction of travel. At that altitude I'd run the engine at whatever RPM/Mixture setting resulted in the smoothest engine. My P.Ponk engine would happily run LOP, but at the altitudes I flew it didn't really matter where you put the mixture as far as the ROP/LOP arguments go.
 
Another benefit, It's easier to hand prop a 2 blade vs a 3 blade.
 
You can run an IO-550 LOP at 13gph, which would be 65% or 193hp. I don’t know what fuel flow the Pponk takes to get that hp, but I’ll guarantee it’s significantly higher. Then there’s the carb ice thing. Not a thing for the IO-550.

If the money isn’t a big issue, I’d take the 550 every day of the week.
 
I love my IO550 but for you I'd probably do the Northpoint XP470. Sounds like you could use the extra performance but I have to imagine the 550 is going to be a significant cost increase compared to the NP.
 
We have a Pponk on ours for the past 1,400 hrs. Very happy with it. 2-blade McCauley and it climbs very well, and it performs well at high DAs. Regularly cruise in the 7-8,000' range at 65%, 10.5 gph and 135 KTAS. Ours was built by Steve Knopp's shop. We'd likely go with Corona Engines when it comes time to OH. Currently have Superior Millenium cylinders, but we had ECI's originally until the FAA made us take them off at ~1,200 hrs. We've had some minor issues with the Milleniums, but much of that is likely due to flying less than we should.
 
I just took delivery of a Northpoint XP470, built on a 520 case. Lycon did the work. They sent me the dyno run sheet, and the engine peaked at 302HP. The engine is in the process of being installed, and I haven't flown with it yet.

When I penciled out the numbers while deciding which way to go with my new engine, I came to the conclusion that the XP470 was the best bang-for-the-buck. There's always something bigger/better/faster, but the XP470 seemed like the best value for my hard-earned AMUs.
 
182, high DA? More hp is the answer but what you really want is more hp at altitude. For that you need a turbo (no STC for that) or a supercharger (these are 20k. It eats 3-5hp but you can fly up to 8k DA without a loss of power. Pretty sweet and is compatible with a PPonk.

I'd do it to my own bird if we needed it but we don’t.
 
SoCal 182 Driver said:
I just took delivery of a Northpoint XP470, built on a 520 case. Lycon did the work. They sent me the dyno run sheet, and the engine peaked at 302HP. The engine is in the process of being installed, and I haven't flown with it yet.

When I penciled out the numbers while deciding which way to go with my new engine, I came to the conclusion that the XP470 was the best bang-for-the-buck. There's always something bigger/better/faster, but the XP470 seemed like the best value for my hard-earned AMUs.
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520 crank, too?

Mine is a 520 crank and a 100 hour Phase-3 470 case that had the oil transfer modified for the crank. There’s very little difference between 470s and 520s, or 550s for that matter.

If I wanted to go all-out I’d get an approval for a cross flow 550, but the investment wouldn’t make sense with the limited gross weight. The Pponk is the best compromise, and doesn’t require plumbing an accumulator tank and electric fuel pump.
 
wheaties said:
182, high DA? More hp is the answer but what you really want is more hp at altitude. For that you need a turbo (no STC for that) or a supercharger (these are 20k. It eats 3-5hp but you can fly up to 8k DA without a loss of power. Pretty sweet and is compatible with a PPonk.

I'd do it to my own bird if we needed it but we don’t.
Click to expand...
It really depends on what your need is. If you aren't trying to routinely fly out of high DA airports at MGTOW, a Pponk can be the right answer for a much lower cost and service complexity.

I can climb at 700 fpm at 9,000' DA with full fuel (75 gal) and 2 passengers with some bags. I can add people and lose some fuel and still do well on a warm summer day out of Mammoth or Big Bear.

Ours is built on an O-470-S heavy case.
 
Jeff Oslick said:
It really depends on what your need is. If you aren't trying to routinely fly out of high DA airports at MGTOW, a Pponk can be the right answer for a much lower cost and service complexity.

I can climb at 700 fpm at 9,000' DA with full fuel (75 gal) and 2 passengers with some bags. I can add people and lose some fuel and still do well on a warm summer day out of Mammoth or Big Bear.

Ours is built on an O-470-S heavy case.
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With what crank? An -S crank isn’t compatible with the Pponk mod.
 
The only difference between 470 and 520 cranks is the oil transfer. My 520 crank required machining my 470 case for the 520’s oil transfer collar. I’ve never heard of anyone converting a 520 case for a 470 crank, but that’s why I asked.
 
Stewartb said:
The only difference between 470 and 520 cranks is the oil transfer. My 520 crank required machining my 470 case for the 520’s oil transfer collar. I’ve never heard of anyone converting a 520 case for a 470 crank, but that’s why I asked.
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Lycon did the work, and they represented to me that it would be done on a 520 core. There was no discussion of converting the 520 case to accept a 470 crank, so I can only assume they used a 520 crank. I also reviewed the invoice, and there was no mention of case modification to accept a 470 crank.
 
550 crank is like 12 pounds heavier than the 520 crank. add a 3 blade prop and the cg moves forward quite a bit.
i have a heavy case 520 and 86" 401, cg is pretty far forward, another 12 pounds (might be 15) would be quite nose heavy.
 
I recently installed a Texas Skyways O-520 in my 182P.
I’ve flown it about 14 hours so far, so I’m in the breakin period.
During such a time they want you to run more rich and heavy on the throttle, so I can’t give an accurate fuel burn. However it averages out to about 19gph currently.

One thing I wish they provided was a graph that shows what throttle/manifold at different altitudes gives power percentages.

I will say that there’s no greater feeling than taking off and climbing out at 1000fpm at 100kts.

The problem is that now I tasted a little speed and want something even faster like a mooney. Lol
 
Wagondriver said:
550 crank is like 12 pounds heavier than the 520 crank. add a 3 blade prop and the cg moves forward quite a bit.
i have a heavy case 520 and 86" 401, cg is pretty far forward, another 12 pounds (might be 15) would be quite nose heavy.
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What’s your empty CG? My 180 is equipped the same, has a firewall Odyssey, and hydraulic ski plumbing in place. Empty CG is 38.7”. No problems with any flight loads except running really light with Fluidyne skis. That empty CG is 33.2”, and that’s simple to manage.
 
ktup-flyer said:
Do you have a stol kit?
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For myself, the Pponk/C401 upgrade is the best STOL mod going. Most pilots can get a Cessna in shorter than they can get out. Especially with obstacles. More power and thrust fixes it.

Keep in mind the early 180 gross was 2550#. Mine is 3190#. Most other guys’ are somewhere in between. The same range applies to 182s. The plane’s gross weight and how a guy uses it are factors to consider.
 
Stewartb said:
For myself, the Pponk/C401 upgrade is the best STOL mod going. Most pilots can get a Cessna in shorter than they can get out. Especially with obstacles. More power and thrust fixes it.

Keep in mind the early 180 gross was 2550#. Mine is 3190#. Most other guys’ are somewhere in between. The same range applies to 182s. The plane’s gross weight and how a guy uses it are factors to consider.
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Yea, my 182 is 3110 mtow, and has the factory cambercuff wing. It does fine on short fields, but could definitely use a PPonk. The O-470-U is better than the earlier 470s though, imo
 
Did you make up your mind yet? I just put a 520 in my 58. I like the simplicity of it.

Not that it’s a significant improvement but you’ll actually burn less fuel than the 470. About a gallon an hour less at most airspeeds.
 
Whitewaterraftr said:
Not that it’s a significant improvement but you’ll actually burn less fuel than the 470. About a gallon an hour less at most airspeeds.
Click to expand...
What power settings and altitude are you using to get less fuel burn?
At 7000’, 22”MAP, 2400RPM I was only able to lean back to around 17gph. O-470 would have been around 12-13gph

I notice about a 3-4GPH increase in all types of flight..
however I don’t complain one bit about the climb power
 
Pretty much all power settings and all altitudes my 520 burns an average of 1 gallon less. Unless I’m pouring the coals to it.

470 was around 13 gallons at at 135 indicated, 520 is around 12 gallons at 135 indicated.

My dads was the same way and that’s what Steve Knopp used to say.
 
Just curious, what power settings are you comparing?

23 squared with the 470 is about the same as 21 squared or 2200,19” with the 520
 
Whitewaterraftr said:
Just curious, what power settings are you comparing?

23 squared with the 470 is about the same as 21 squared or 2200,19” with the 520
Click to expand...

I never thought about just doing a speed comparison for GPH. Now I feel like a dingus. Lol

But in reality, all of my standard power settings. 23sq/2350sq,3000sq all yield higher fuel burn.
One issue that may be compounding this is that if I lean too much, CYL 6 likes to climb up to 380+ on the temp gauge quick. The others will hang back at 340-350.
Very frustrating
 
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