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SinkorSwim
April 4th, 2012, 02:15 PM
Just curious if there are any owners or fliers of Cessna's with the P-Ponk 470?

Skylane81E
April 4th, 2012, 02:16 PM
Yes, I'm sure they will chime in in due time.


I want one.........

Tom-D
April 4th, 2012, 02:17 PM
Just curious if there are any owners or fliers of Cessna's with the P-Ponk 470?
I care for 2, can I help?

SinkorSwim
April 4th, 2012, 02:33 PM
The PPonk seem to be an outstanding hybird of aviation engines. Taking the 470 and marrying it to a 520; kinda sorta.. :)

In a Cessna 182 I imagine there are really no downfalls? :dunno:

thx

Skylane81E
April 4th, 2012, 03:00 PM
Burns more fuel with the go fast knob in.

I flew along with two other 182s once, both the same model, one with a fresh 470 and the other a fresh pponk. Every leg they bured with in a tenth for the same airspeed, but the pponk could climb faster and had the option of more speed.


Granted my newer plane with a nearly run out 470 burned 2-3 gallons less fuel per leg but I attribute that to aerodynamic clean ups between the early 60s and the 80s

denverpilot
April 4th, 2012, 03:17 PM
The PP is on our short list of what to do when it's time to replace our engine.

The only complaint I've heard is that you'd better buy all new baffling and get it right or it's going to cook itself, but that's true of any new engine. Some conversion purchasers have had to fuss with baffles for a whole to get temps right.

Putting the right prop on it also seems to change some people's view of them. Again, normal.

Skylane81E
April 4th, 2012, 03:19 PM
The right prop on a 470 is huge, we put a McCauley 3 blade on our school plane

Holly heck I want one now!

Jeff Oslick
April 4th, 2012, 03:40 PM
We've had a PPonk hung on our 'Q for the last 3-1/2 years, >500 hours, and it has been running like a top. Climbs like a homesick angel. We have the ECI Titan cylinders, which give about another 10 hp over the other cylinder options. I know, there have been folks with problems with their ECIs, but we have experienced no issues to date (and we do oil analysis with Blackstone at every oil change).

The heat problems some have experienced are largely attributed to too-small carb jets installed on some several years ago. I think all the shops who build them up have learned from that by now (ours was built by Steve Knopp's shop). We have not had heat problems. Sea level WOT fuel flow is 22 gph (the folks with heat issues were running <21 gph at WOT). On a really hot day in cruise we have one cylinder that gets a little warm, but I pop a couple notches of cowl flap and it stays below 370 F (my target max CHT).

I can cruise at 14,000' at 137 KTAS leaned out to 9.2 gph. We cannot run LOP, but over about 9,000' we're comfortable leaning it out to peak EGT (~65% power or less), and it runs well at pretty low fuel flows. The good part is you can get to that altitude much faster than a stock 182. High density altitude operations go very well too; we have regularly operated out of both Big Bear, CA and Mammoth Lakes, CA.

If you're just buzzing around at relatively low altitudes, it will burn about the same or just slightly more than a comparable stock O-470 at the same speeds.

Any other questions, fire away! Or, if you're seriously considering purchasing one, don't hesitate to call Steve Knopp directly. He and his whole crew were extremely helpful throughout the entire purchase process, and very professional. We did an engine swap, not a rebuild of our own. Absolutely zero complaints here.

Jeff

Tom-D
April 4th, 2012, 09:13 PM
the 0-470-50 is a new 0-520,

wabower
April 4th, 2012, 09:51 PM
My Cessna 180C has a 470-50. Great climb and surprisingly good cruise speed at 7-9k. 150 kts not unusual. Narrow fuse with 3-blade.

SinkorSwim
April 5th, 2012, 09:07 AM
Thx guys !

I hope to be able to report very soon on a Cessna 182 PPonk 470 3 blade Hartzell prop. :)

denverpilot
April 5th, 2012, 06:42 PM
Thx guys !

I hope to be able to report very soon on a Cessna 182 PPonk 470 3 blade Hartzell prop. :)

Looking forward to it. Are you having Steve's shop do the conversion or one of the licensees?

SinkorSwim
April 5th, 2012, 10:44 PM
Looking forward to it. Are you having Steve's shop do the conversion or one of the licensees?

Purchasing ready made from a liscensee...

Henning
April 6th, 2012, 03:40 AM
the 0-470-50 is a new 0-520,

If I wanted to do the PPonk cyl kit on my 310 what all would be involved?

timwinters
April 6th, 2012, 07:47 AM
And the TBO (on paper at least) increases to 2,000 hours for a ponk if an oil filter is installed. That's quite an increase over the stock o470.

If I wanted to do the PPonk cyl kit on my 310 what all would be involved?

I think it's approved for 180s and 182s only.

Tom-D
April 6th, 2012, 10:26 AM
If I wanted to do the PPonk cyl kit on my 310 what all would be involved?

Developing a one time STC.

the 0-470-50 starts with a new set of 0-520 cases, because 0-520 cylinders won't fit the 0-470 cases. so, when you buy from PEEPONK you get a new engine. with your data tag.

denverpilot
April 6th, 2012, 04:52 PM
Developing a one time STC.

the 0-470-50 starts with a new set of 0-520 cases, because 0-520 cylinders won't fit the 0-470 cases. so, when you buy from PEEPONK you get a new engine. with your data tag.

Not according to their website.

http://www.pponk.com/HTML%20PAGES/O470_conversion.html

http://www.pponk.com/HTML%20PAGES/engine_overview.html

Tom-D
April 6th, 2012, 08:30 PM
Not according to their website.

http://www.pponk.com/HTML%20PAGES/O470_conversion.html

http://www.pponk.com/HTML%20PAGES/engine_overview.html

So, I said you get new 0-520 cases, he says

""To convert a stock Continental O-470 to a O-470-50 SUPER EAGLE several internal changes need to be made to the engine. First, and most obvious is to exchange the O-470 cylinders for O-520 cylinders which increases engine displacement by 50 cubic inches. O-470 models R and S require a new crankshaft. The crankshaft counterweights are reconfigured and case modifications are made. The cylinders are fitted with low compression pistons which are precision balanced to within .5 grams. The carburetor is also modified. All original external accessories are overhauled and used on the O-470-50. The end product is essentially a O-520 which is carbureted and derated to 265-275 hp. Recommended TBO for the O-470-50 is 2,000 hours.

He simply means they are brought up to 0-520 spec. Its easier and cheaper to buy a 0-520 case.

I watched Steve build the -50, they are beautiful engines.

wabower
April 6th, 2012, 10:52 PM
My engine was built from a TSIO-520 case, as noted at the end of the first linked article.


Not according to their website.

http://www.pponk.com/HTML%20PAGES/O470_conversion.html

http://www.pponk.com/HTML%20PAGES/engine_overview.html

denverpilot
April 6th, 2012, 11:01 PM
Haven't heard anyone unhappy with then yet. Hopefully Steve's still doing them when we need an engine.

wabower
April 6th, 2012, 11:04 PM
His licensees build them as well. They are extremely smooth engines. No comparison between this engine and the 470 on the prior plane.

Haven't heard anyone unhappy with then yet. Hopefully Steve's still doing them when we need an engine.

Henning
April 6th, 2012, 11:10 PM
Developing a one time STC.

the 0-470-50 starts with a new set of 0-520 cases, because 0-520 cylinders won't fit the 0-470 cases. so, when you buy from PEEPONK you get a new engine. with your data tag.

What difference/advantage from Cont 520?

Tom-D
April 6th, 2012, 11:30 PM
What difference/advantage from Cont 520?
READ

http://www.pponk.com/HTML%20PAGES/O470_conversion.html

Tom-D
April 6th, 2012, 11:34 PM
The 0-470-50 started with the need for a quick starting float plane engine, with more power. Thus the bigger displacement, and carb.

Henning
April 6th, 2012, 11:36 PM
READ

http://www.pponk.com/HTML%20PAGES/O470_conversion.html

Ahhh, thanks, basically what they are doing is building a carburetted 520.

kgruber
April 8th, 2012, 11:16 AM
Kenmore Air Harbor has a similar STC, but not nearly as popular.

If you buy the PPonk three blade prop, be aware that it will slow your cruise down considerably, add cost, noise, and weight. It does have better initial acceleration, but I wouldn't swap one again.

Jeff Oslick
April 8th, 2012, 10:08 PM
Our Pponk is an O-470U (heavy case) with ECI Titan 520 cylinders. This was not our engine core, this is one Steve built up on his own, so starting with a 520 case is not a preference for him.

I don't understand the above post regarding more noise with the 3-blade prop. We have a 2-blade, with 2700 rpm (5 minute) rating. Now, that is loud. The 3-blade is comparatively quieter. Pponk has a prop tip speed calculator on their website.

Jeff

kgruber
April 9th, 2012, 11:12 AM
I don't understand the above post regarding more noise with the 3-blade prop. We have a 2-blade, with 2700 rpm (5 minute) rating. Now, that is loud. The 3-blade is comparatively quieter. Pponk has a prop tip speed calculator on their website.

Jeff

Jeff,

What is the diameter of your 2 blade? It is the diameter and RPM which determines the noise. Tip design as well.

The McCauley "403" factory 3 blade on my 185 had a 80" diameter. The PPonk "401" replacement is 86". I bought one. There is no question that the PPonk is very much louder.

My opinion comes from having owned, operated, and flown 135 with Cessna 180s, 185s, 206s and 207s.

The PPonk 86" "401" MCauley is great for pulling a heavy floatplane on the step. After that, it takes a back seat to the factory 2 blade in every possible performance category. They are expensive to buy and overhaul. They add weight (especially to a 182) just where you least want it. And,they are WAY slow in cruise.

The main objection the average person living near an airport has against airplanes is their noise. The "401" at 86" is just way too loud, even at 2700RPM. At 2850RPM, in a 185 it is completely unreasonable.

Jeff Oslick
April 9th, 2012, 12:04 PM
Jeff,

What is the diameter of your 2 blade? It is the diameter and RPM which determines the noise. Tip design as well.


We have a McCauley D2AA37C230/90REB-8 prop. When you plug the numbers into Pponk's calculator you can see that at cooler temps, this prop is not efficient at max (2700) RPM so we dial it back a bit. At hot temps, which aren't usually for us, it is in the optimally efficient range.

Jeff

kgruber
April 9th, 2012, 09:59 PM
It looks to me that you are good for full RPM at just about any temp. I could/have be mistaken, but a 90 -8 is a 82" diameter prop. Plug 82/2700/10deg into Steve's calculator.

http://www.pponk.com/HTML%20PAGES/propcalc.html

The way they do that is to start with a 90 inch prop. That is what a late model Cessna 180 with an O-470U/2400RPM would come from the factory as a seaplane prop. That is an EXCELLENT prop.

Yours has been shortened by 8 inches, thus the -8. I think that must be your factory prop, shortened by Cessna because of the reduced ground clearance for the tri-gear. I'd never give that prop up!

Jeff Oslick
April 10th, 2012, 01:42 AM
Not the factory prop. The stock prop for the 77Q model is not on the STC list for Pponk. This was a new one (ours was pretty well run-out when we did the engine swap).

Ted DuPuis
April 10th, 2012, 08:08 AM
A lot of these older STCs will use props that may not be the best as far as noise is concerned. Why they chose the props may have other factors (it's what the prop manufacturer was pushing, cost, etc.).

You may be able to get another prop approved by working with your local FSDO and the prop manufacturer of your choosing. I have thought about trying to do that on the 310 - the McCauley 3-blade props on it are quite noisy, and I'd rather replace them with some quieter Hartzells (Hartzell being my prop manufacturer of choice). They also have lots of hours left on them, so we're keeping them for the time being.

As to noise, the primary factor in noise is diameter. However, design is also a big deal. The purpose of the Hartzell Q-tip props, for instance, is using the curved ends to reduce noise. It does so reasonably well. However, I wouldn't want those props because they are also less forgiving with respect to getting dings from stones, etc. This is important to me since I go to gravel strips semi-routinely.