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New PPONK

eskimo77 said:
What does it take to get the C66 approved for the PPonk? What about the newer 88" 2A34C203?
Click to expand...

My understanding is that Steve (or whoever) determined that the C203 is not compatible with the 470-50 engine,
I assume it's a harmonics / vibrational thing.
The 470-50 uses the same crankshaft counterweight configuration as the 470K,
I have an STC from North Sound Aviation approving the C201 & C203 props on the K engine.
There was an 82" C203 on my engine for like 1300 hours, starting back around 1993, then an 88" C201 for another few hundred.
I've only owned it for 5 years, but no issues that I can detect.
The C203 is a popular prop, installed on a lot of 180/182's--
if it can be approved for the 470-50, that'll save some folks a lot of money as they won't have to buy a new prop when converting to the -50.
 
hotrod180 said:
My understanding is that Steve (or whoever) determined that the C203 is not compatible with the 470-50 engine,
I assume it's a harmonics / vibrational thing.
The 470-50 uses the same crankshaft counterweight configuration as the 470K,
I have an STC from North Sound Aviation approving the C201 & C203 props on the K engine.
There was an 82" C203 on my engine for like 1300 hours, starting back around 1993, then an 88" C201 for another few hundred.
I've only owned it for 5 years, but no issues that I can detect.
The C203 is a popular prop, installed on a lot of 180/182's--
if it can be approved for the 470-50, that'll save some folks a lot of money as they won't have to buy a new prop when converting to the -50.
Click to expand...
I like the C203, too. I am using it on an IO470 install.
 
I just (last May) installed a 470-50 PPonk built by Ly-Con in our '73 180J. We went with higher compression pistons and overhauled cylinders. Supposedly dyno'd 310hp @ 2,700 but who knows...

Runs well and pulls strong with MT 3-blade. Took almost six months, if I recall, to get the engine built.
Would I do it again with Ly-Con? Yes, if I could have the engine done independent of an exchange and I had a decent running 470 already in the bird.
 
JohnnyR said:
I just (last May) installed a 470-50 PPonk built by Ly-Con in our '73 180J. We went with higher compression pistons and overhauled cylinders. Supposedly dyno'd 310hp @ 2,700 but who knows...

Runs well and pulls strong with MT 3-blade. Took almost six months, if I recall, to get the engine built.
Would I do it again with Ly-Con? Yes, if I could have the engine done independent of an exchange and I had a decent running 470 already in the bird.
Click to expand...

I'm wondering if anyone has a torque curve from LyCon's dyno after they did the work to their engine. And really interested in a before and after...
I haven't met anyone so far with that piece of paper. If RPM is limited, then extra HP must come from torque at a given RPM... If extra torque comes from cleaning up ports (more air) then why is there no mixture enrichment specified? These questions are what turned me away from this option but I really would be happy with a valid answer.
Jose
 
If the fuel flow remains the same as limited by carb parts how can more air from improved volumetric efficiency due to mods not require more fuel? Note the IO-520 to IO-550 increased fuel flow for example. That assumes ultimate fuel flow is limited by nozzle jet size.
Gary
 
BC12D-4-85 said:
If the fuel flow remains the same as limited by carb parts how can more air from improved volumetric efficiency due to mods not require more fuel? Note the IO-520 to IO-550 increased fuel flow for example. That assumes ultimate fuel flow is limited by nozzle jet size.
Gary
Click to expand...

Yep.. Just look at what Continental had to do to advertise a 10HP increase.. Crossflow heads etc. (IO550N) If it was as easy as cleaning up some ports, why on earth would the factory not choose to do so? I really don't believe any of it, in fact I wouldn't be surprised if the roughness on the ports actually helps with turbulation. (golf ball theory).
I asked LyCon if they enriched the mixture to offset the increased flow... answer is, "no we adhere to the type certificate" asked about before and after dynos for other IO520s, answer was, "that would be like searching for a needle in a haystack". Asked a friend about whether he had any dyno results (after his clients had bought more than a few engines from them) and he said, " ya know, I never did get one..."
Probably nice people there, and probably build very nice dependable engines, and I wish them the best, but I cannot connect the logic on the claims made.
As I said, I'd love to see a before and after dyno.. with fuel flow, egt, etc.. I'd buy one if I thought the physics were logical.
Jose

Jose
 
The flow went up considerably with the modified carb.

I flight plan for 15.5-16gph. Power isn’t free.

The type certificate calls for enriched mixture to match the larger heads. They (Ly-Con) do go with richer than earlier specified jetting because of field reports years back about engines running lean post-mod.

Ly-Con or anyone else will tell you that the larger power increases on these modified engines mainly come from three things - larger pistons/jugs; higher compression pistons; higher rpm (if your prop choice will support that).

There’s no wizardry in their claims or work (although dyno results are always suspect). You can analyze it all you want but most people who install the PPonk or TX Skyways mod’d engines feel after their first few flights that there’s no better mod for the $ for 180’s or early 182’s if your mission requires more oomph.

Our 180’s performance differences at high DA with heavy loads was easily discernible - both with the former 2-blade MT and the current 3-blade MT.

46 Cub said:
Yep.. Just look at what Continental had to do to advertise a 10HP increase.. Crossflow heads etc. (IO550N) If it was as easy as cleaning up some ports, why on earth would the factory not choose to do so? I really don't believe any of it, in fact I wouldn't be surprised if the roughness on the ports actually helps with turbulation. (golf ball theory).I asked LyCon if they enriched the mixture to offset the increased flow... answer is, "no we adhere to the type certificate" asked about before and after dynos for other IO520s, answer was, "that would be like searching for a needle in a haystack". Asked a friend about whether he had any dyno results (after his clients had bought more than a few engines from them) and he said, " ya know, I never did get one..."Probably nice people there, and probably build very nice dependable engines, and I wish them the best, but I cannot connect the logic on the claims made.As I said, I'd love to see a before and after dyno.. with fuel flow, egt, etc.. I'd buy one if I thought the physics were logical.JoseJose
Click to expand...
 
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JohnnyR said:
The flow went up considerably with the modified carb.

I flight plan for 15.5-16gph. Power isn’t free.

The type certificate calls for enriched mixture to match the larger heads. They (Ly-Con) do go with richer than earlier specified jetting because of field reports years back about engines running lean post-mod.

Ly-Con or anyone else will tell you that the larger power increases on these modified engines mainly comes from three things - larger pistons/jugs; higher compression pistons; higher rpm (if your prop choice will support that).

There’s no wizardry in their claims or work (although dyno results are always suspect). You can analyze it all you want but most people who install the PPonk or TX Skyways mod’d engines feel after their first few flights that there’s no better mod for the $ for 180’s or early 182’s if your mission requires more oomph.

Our 180’s performance differences at high DA with heavy loads was easily discernible - both with the former 2-blade MT and the current 3-blade MT.
Click to expand...

Yes, for Pponk modified, of course there are differences. I was referring to any engine in general after passing through their shop. My first inquiry was regarding a factory new IO520D. I was considering sending it to them after purchase for the extra power. They said they get about 20-30 percent more power after their re-work. That led to the questions.
Yes, Steve Knopp's mods involve more fuel flow, etc but that is separate from LyCons claims. I would love to see the dyno curve that shows a Continental engine of 520 inches displacement turning even 2850 rpm at 310 HP. The factory will promise that with a turbo but you're not going to see it with a carburetor and surely not at 2700 rpm.
Sorry, I'll go quiet again..
 
eskimo77 said:
What does it take to get the C66 approved for the PPonk? What about the newer 88" 2A34C203?
Click to expand...

Using Pponk's tip speed calculator, it looks like an 88" prop at 2700 rpm on a standard temp (59*) day
turns up to almost .93 mach-- just above their suggested sweet spot of .88-.92.
Trimming it back an inch to 87" would get it down to just under .92.

https://pponk.com/props/#1463774934977-1d7f57b4-6b2b​
 
No need to go silent. You're making assertions that are stimulating informative discussion - all to interested readers' benefit.
Here's the dyno report
View attachment PPonk Dyno.pdf

A pilot/mechanic near Boston had a similar PPonk engine built up (higher compression pistons, flow porting & polishing) that dyno'd at a different facility @ 302CHP @ 2700, if I am recalling correctly. http://bushwagoneast.com/category/pponk/

It's not rocket science - racers have done this for years. http://backcountrypilot.org/forum/porting-and-polishing-cylinders-15566 ​

46 Cub said:
Yes, for Pponk modified, of course there are differences. I was referring to any engine in general after passing through their shop. My first inquiry was regarding a factory new IO520D. I was considering sending it to them after purchase for the extra power. They said they get about 20-30 percent more power after their re-work. That led to the questions.
Yes, Steve Knopp's mods involve more fuel flow, etc but that is separate from LyCons claims. I would love to see the dyno curve that shows a Continental engine of 520 inches displacement turning even 2850 rpm at 310 HP. The factory will promise that with a turbo but you're not going to see it with a carburetor and surely not at 2700 rpm.
Sorry, I'll go quiet again..
Click to expand...
 

Attachments

  • PPonk Dyno.pdf
    110.2 KB · Views: 354
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Forgive me if I'm oversimplifying - wouldn't an increase in power (due to porting or whatnot) already be compensated by the carb? I'd think a free-er flowing engine would pull more air per engine revolution (and thus more fuel) through a carb.

I'm not a carb guy though, I grew up modifying EFI systems. Please tell me if I'm mistaken!
 
My Pponk has had the primary jet adjusted for more flow 4 times. At the end of the day fuel flow is about temp management, both for CHTs and ambient conditions. HP comes from displacement, compression, and RPM. Johnny should have a 3-4% advantage for 8.5-1 over my 7.5-1.

Engines are air pumps, not fuel pumps. If you want to make big power you need to pack more air into the cylinders. You need a blower for that. Porting and polishing make engines smoother and cooler running but big horsepower claims don't make sense. To me, anyway. Not until it makes a significant increase in manifold pressure.
 
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More air flow or more properly air mass will cause the carb to add fuel. But there's a limit to fuel flow (carb or injectors) that's determined by the diameter of the hole the fuel has to pass through in a carb and some by the viscosity/density of the fuel - avgas versus auto fuel. In FI system pressure is variable and that plus orifice diameter determines flow. Autos can incorporate an air mass flow sensor to help adjust FI flow.

Gary
 
… and for those that are wondering about dyno testing - Ly-Con has a dynamometer with a load cell that tests torque directly.
From them when queried about "plumping up" dyno results, which probably happens more often than not in high perf build shops: "​That’scorrect – thereare “correction factors” that can be plugged in based on various assumptions,but our torque numbers are referenced against a dead-weight calibration. Recalibrated daily at a minimum, sometimes multiple times per day depending onconditions."
 
46 Cub said:
Yep.. Just look at what Continental had to do to advertise a 10HP increase.. Crossflow heads etc. (IO550N)
Click to expand...

What a leap for Continental. Cold air induction from the top. Exhaust out the bottom. Common sense in Mobile! I saw on the Skywagon site that some guys have installed those motors in Skywagons. Sounds fun!
 
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46 Cub said:
Yes, for Pponk modified, of course there are differences. I was referring to any engine in general after passing through their shop. My first inquiry was regarding a factory new IO520D. I was considering sending it to them after purchase for the extra power. They said they get about 20-30 percent more power after their re-work. That led to the questions.
Yes, Steve Knopp's mods involve more fuel flow, etc but that is separate from LyCons claims. I would love to see the dyno curve that shows a Continental engine of 520 inches displacement turning even 2850 rpm at 310 HP. The factory will promise that with a turbo but you're not going to see it with a carburetor and surely not at 2700 rpm.
Sorry, I'll go quiet again..
Click to expand...

I would be curious who at LyCon told you they get 20-30 percent more power? I talk to Ken several times a week and I have never heard any claims like that. Their flow matched cylinders run way smoother and having run the same prop on a 160 hp Lycoming and a 160 hp LyCon engine there was no comparison, it got off quicker, hands down. There are so many parameters that you can't compare apples to oranges. If I have earned anything that is that there are a lot of variables.
 
stewartb said:
Where's the science?
Click to expand...
So are you saying that flow matching cylinders doesn't make an engine smoother? Flowing and balancing and paying attention to lots of little things doesn't make any difference?

I can post all kinds of articles explaining all kinds of this stuff but my opinion has come from flying lots of airplanes and these engines consistantly standing out.
 
stewartb said:
Where's the science?
Click to expand...
Really Stewart. A Laminar flow stream moves more quantity and turbulent flow stream, learned that basic of flow dynamics long before I took it in class. In a pipe, channel or induction manifold the sides, bends, fittings and yes the cylinder valves and the shape of their seats induce turbulence and reducing that turbulence by smoothing and easing the angles makes them run smoother by reducing turbulence and thus improving flow. So to your point more flow = more potential hp and the potential gains are there but yes they are not as dramatic as hanging a turbo.
 
Stewart, it's just 7th grade science - probly before that, but that's the lowest grade level I taught - science is about trying stuff to see what happens. That's where.

You were asking about empirical evidence, not science - i.e. engineering which is my background - but you didn't recognize that you were doing so, or recognize the evidence, so didn't understand the answers.
 
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We make improvements to affect a result. Theorize-experiment to validate. With respect to engines I've had an interest all my life and a very specific interest in high performance airplane engines for the past 3-4 years. I've talked to the big engine builders (dealt with a few) and have talked to some of the premier aerobatics guys about how to wring out power. In my own engines I've got limits on manifold pressure (normally aspirated), RPM, and known displacement and compression. The big factories know precisely what their engines will develop before they put them on the dyno. The dyno is mostly to prove the engine is producing rated power. In my Superior engine we added a new fuel servo that was said to increase power, and sure enough it made 5 HP on the dyno, which Superior was very impressed with. All cool stuff. With respect to well known engine shops that consistently report approx 10% more power than the factories I've asked the factories what the variable is. They're very hesitant to say anything but my own take on it (and the take of several in-the-know friends) is that the variable is the dyno. That may be in the dyno itself or in the setup, because there are ways to cheat to get higher numbers, but those cheats aren't applicable to a normal installation. Obviously my curiosity and questions have struck a nerve with some guys. I'll leave it alone. I have a really cool high performance engine to install and when it warms up... to fly. I did my research, I asked the questions, I spent my money. The end. Adios, gents. Happy flying.
 
Some here remind me of my drink’n days and walking into a hole in the wall bar where ya ain’t known... piss’n contests to suit every ol farts desire!
Love the video Steve,Over on another thread, Should post more of’m, proves that flying still takes place occasionally
 
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stewartb said:
They're very hesitant to say anything but my own take on it (and the take of several in-the-know friends) is that the variable is the dyno. That may be in the dyno itself or in the setup, because there are ways to cheat to get higher numbers, but those cheats aren't applicable to a normal installation.
Click to expand...
True. And to get an apples to apples comparison, bike guys ask for a certain set of dyno parameters (SAE correction factor, standard CF, smoothing, tire pressure, etc., etc.)
 
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