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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.

FlyingBob
June 26th, 2014, 01:29 PM
Hi gang. It's my first post on here, and am excited to share info about our passion...flying.
I am on this forum because I own a 78' C-182Q with the P Ponk upgrade, as well as the Hartzell 3 blade scimitar prop, and speed mods. I have had this airplane for about a year now, and haven't done a lot of flying with it, but wanted to see what others think about this engine in a 182...specifically fuel burn/TAS.
Now, I have been calculating that my burn is about 15GPH, but the engine only has 60hrs on it, so it might be burning more fuel than normal during the break in period. I have been getting 140-150kts on average.

When is an aircraft engine typically considered to be "broken in"? Also what should I see for a fuel burn at normal cruise once it is broken in? I am getting a digital fuel flow gauge installed soon, so this will show me an instantaneous burn.

Looking forward to hearing from P Ponk fliers out there!

Henning
June 26th, 2014, 01:36 PM
Welcome. Never flew the PPonk, flew the 260 Katmai, it was beyond impressive. I'm interested to see what this thread brings.

FlyingBob
June 26th, 2014, 01:41 PM
I'm anxious to hear from people regarding this thread too!
I get very surprised reactions from other pilots when I tell them the numbers on the airplane. They all say they've never heard of a 182 averaging 145kts, let alone one with 270HP.

Jeff Oslick
June 26th, 2014, 04:47 PM
We have a '77 182Q w/Pponk. About 800 hours on it now after 5.5 years. That fuel flow for low to mid 140 knots sounds about right. During break-in (and *only* during break in) we ran it to 154 KTAS down low with some ridiculous fuel burn of around 19 gph. You can fly higher and lean it out - I like to fly high over the Sierras, 13K at 137 KTAS and 9.5 gph. Around 8K or so I'll do 137 KTAS and around 12.2-12.5 gph. I prefer to fly it at low power and lean to peak EGT (we have full engine monitoring equipment). LOP doesn't really work for me in this plane, and at the 60-65% power I cruise at, pretty much any mixture setting is safe.

At 60 hours, you are well past the break-in period. According to our CHTs, we were "broken in" at around 5 hours.

Jeff

denverpilot
June 27th, 2014, 01:41 AM
Want. :)

We've discussed that the P.Ponk is probably the right way to go when our engine says it's time. Not there yet.

Jeff Oslick
June 27th, 2014, 12:43 PM
Just so everyone doesn't think the Pponk is an infallible gift from the aviation gods, we are looking at pulling a couple jugs next week on ours. Possibly a valve issue in one cylinder (high CHT during climbs) and a ring issue in another (generating some metal flakes in the filter and elevated chromium and lead in our oil analysis). It is a mid-time big-bore Conti, and our use-hours fell off a bit the last couple years leading to some longer than desirable down times, so none of this is surprising to us.

Fortunately, with a 3-way partnership, the pain shouldn't be too bad.

Jeff

Ted DuPuis
June 27th, 2014, 01:13 PM
High CHTs are a common issue with increase HP STCs since there is rarely an improvement in the cooling department. Usually turning up the fuel flow a bit helps as does paying particular attention to cooling and doing a cruise climb vs. a max performance climb. In the 310, we'll climb between 140-160 MPH IAS at 25"/2500 RPM. We also have played with fuel flows a bit (on the up side) to get the CHTs down on climb.

Jeff Oslick
June 27th, 2014, 01:33 PM
High CHTs are a common issue with increase HP STCs since there is rarely an improvement in the cooling department. Usually turning up the fuel flow a bit helps as does paying particular attention to cooling and doing a cruise climb vs. a max performance climb. In the 310, we'll climb between 140-160 MPH IAS at 25"/2500 RPM. We also have played with fuel flows a bit (on the up side) to get the CHTs down on climb.

Since this engine was installed, we have EGTs and CHTs recorded on all cylinders, plus a fuel flow monitor. The high CHT we are seeing is a change in this cylinder from the past 800 hours of operation. There is no change in fuel flow, and we have checked the induction system. There also isn't any apparent change in the baffling, so we we're reduced to assuming there could be a valve issue developing in this cylinder. Note this is a small change at this point - unrestricted climb CHT under similar OATs used to peak around 385F in this cylinder, now we have to reduce climb rate to 500 fpm to keep the temp below 400F, which is what we consider our "warning" temp. Folks flying with a single CHT gauge would likely have no clue such a problem was developing, but we tightly manage the maintenance of this plane. 400F is also a conservative temp to use as a warning level.

jsstevens
June 27th, 2014, 02:18 PM
Since this engine was installed, we have EGTs and CHTs recorded on all cylinders, plus a fuel flow monitor. The high CHT we are seeing is a change in this cylinder from the past 800 hours of operation. There is no change in fuel flow, and we have checked the induction system. There also isn't any apparent change in the baffling, so we we're reduced to assuming there could be a valve issue developing in this cylinder. Note this is a small change at this point - unrestricted climb CHT under similar OATs used to peak around 385F in this cylinder, now we have to reduce climb rate to 500 fpm to keep the temp below 400F, which is what we consider our "warning" temp. Folks flying with a single CHT gauge would likely have no clue such a problem was developing, but we tightly manage the maintenance of this plane. 400F is also a conservative temp to use as a warning level.

Curiosity side question: What is the mechanism for valve problems increasing CHT? I can understand a leaky exhaust valve causing a rise in EGT.

John

Edit: Change "amusing", thanks autocorrect, for "causing".

Ted DuPuis
June 27th, 2014, 03:03 PM
Could also be an ignition issue, worth looking into. But if you're seeing 385F in normal unrestricted climb, that's pretty good.

Jeff Oslick
June 27th, 2014, 03:37 PM
Curiosity side question: What is the mechanism for valve problems increasing CHT? I can understand a leaky exhaust valve causing a rise in EGT.


A valve problem (e.g., sticking) can lead to excessive pressures during the combustion cycle, elevating CHT. The last borescope look we had a few weeks ago didn't reveal anything obvious. Changed the oil and ran for another 10 hours.

We have also checked the timing and put in new plugs, doesn't appear to be an ignition issue, unless it is a hidden issue with the spark plug lead.

Jeff

Jeff Oslick
June 27th, 2014, 03:46 PM
But if you're seeing 385F in normal unrestricted climb, that's pretty good.

It's been a nearly-perfect engine until this issue. Only other issues we've had were a few minor oil leaks (which I learned about 10 years ago is the sign of a big-bore Conti that has actually been run...).

jsstevens
June 27th, 2014, 03:47 PM
A valve problem (e.g., sticking) can lead to excessive pressures during the combustion cycle, elevating CHT. The last borescope look we had a few weeks ago didn't reveal anything obvious. Changed the oil and ran for another 10 hours.

We have also checked the timing and put in new plugs, doesn't appear to be an ignition issue, unless it is a hidden issue with the spark plug lead.

Jeff

Thanks. I read, I learn. Someday I might own one of these beasts and need to know this stuff.

John

Henning
June 27th, 2014, 04:50 PM
Just so everyone doesn't think the Pponk is an infallible gift from the aviation gods, we are looking at pulling a couple jugs next week on ours. Possibly a valve issue in one cylinder (high CHT during climbs) and a ring issue in another (generating some metal flakes in the filter and elevated chromium and lead in our oil analysis). It is a mid-time big-bore Conti, and our use-hours fell off a bit the last couple years leading to some longer than desirable down times, so none of this is surprising to us.

Fortunately, with a 3-way partnership, the pain shouldn't be too bad.

Jeff

Out of curiosity, how rich do you run?

Jeff Oslick
June 27th, 2014, 05:55 PM
Out of curiosity, how rich do you run?

I run ~125 ROP at >70% power. In cruise (<65%), I run at peak or if the engine is cooperating, a bit lean of there. One of the partners is more aggressive than I in the leaning category than me. I haven't flown with him enough recently to really know what if anything he is doing differently. That may or may not be a subject of discussion on further examination of the engine, but I have no reason to believe he is operating it too lean at too high a power setting. We started in this plane with a stock O-470, and in cruise run the same TAS as we used to, just with more hp on tap up front for climb.

I suspect our issues are more related to reduced hours on the engine in the past couple years more than anything else. A 2-3 week layover between flights hasn't been uncommon.

Jeff

denverpilot
June 27th, 2014, 08:10 PM
It's been a nearly-perfect engine until this issue. Only other issues we've had were a few minor oil leaks (which I learned about 10 years ago is the sign of a big-bore Conti that has actually been run...).


ROFL! :)

Dr. O
June 27th, 2014, 08:48 PM
Having owned Lanes and various Continental engines over the years this thread has been interesting.
The loudest Continental engine I had was an IO-520D in a super viking with the long 2 blade prop. It would shake the airport on takeoff. But it cruised like a scalded cat.
In a P-Ponk I would tend to prefer the 2 blade for the cruise efficiency over a 3 blade, even if the 2 blade gives up a bit of climb. I spend way more time in cruise than I do in climb.
The fastest stock Lane I had was a 56 model with the lower hp engine but the straight tail. It annoyed our local Chevy dealer with his brand new, slickly styled, swept tail Lane that I would slide right past him by a few knots. (I was lighter also)

I always said, and still do, that if I had to pick just one airplane for my entire life it would be the Skylane.

Ted DuPuis
June 27th, 2014, 10:00 PM
It's been a nearly-perfect engine until this issue. Only other issues we've had were a few minor oil leaks (which I learned about 10 years ago is the sign of a big-bore Conti that has actually been run...).

That isn't necessarily true, although leaks are common. But for reference, the 2100 SMOH factory remans on the 310 didn't leak a drop of oil when we pulled them for overhaul.

It really does depend on who does the work.

Henning
June 28th, 2014, 05:06 AM
I run ~125 ROP at >70% power. In cruise (<65%), I run at peak or if the engine is cooperating, a bit lean of there. One of the partners is more aggressive than I in the leaning category than me. I haven't flown with him enough recently to really know what if anything he is doing differently. That may or may not be a subject of discussion on further examination of the engine, but I have no reason to believe he is operating it too lean at too high a power setting. We started in this plane with a stock O-470, and in cruise run the same TAS as we used to, just with more hp on tap up front for climb.

I suspect our issues are more related to reduced hours on the engine in the past couple years more than anything else. A 2-3 week layover between flights hasn't been uncommon.

Jeff

75°-125° ROP is the absolute worst temp range to run at. Try 150° and see what happens.

Henning
June 28th, 2014, 05:09 AM
A valve problem (e.g., sticking) can lead to excessive pressures during the combustion cycle, elevating CHT. The last borescope look we had a few weeks ago didn't reveal anything obvious. Changed the oil and ran for another 10 hours.

We have also checked the timing and put in new plugs, doesn't appear to be an ignition issue, unless it is a hidden issue with the spark plug lead.

Jeff

:confused: How? Valves stick open, not shut. If a valve sticks shut, you will immediately break something in the valve train, usually bending the push rod. Once it happens, you lose that cylinder until repaired. Sticking and burnt valves cause high EGT, not CHT.

Ted DuPuis
June 28th, 2014, 09:47 PM
75°-125° ROP is the absolute worst temp range to run at. Try 150° and see what happens.

Most people figure it's about 25-80 ROP is the worst. That's when CHTs and ICPs peak.

txflyer
June 28th, 2014, 10:29 PM
Tagging in because we put an MT prop on our C-180G in anticipation of a PPonk or 0-550 upgrade when it's time. The mating of the two blade MT to the 180 frame I haven't regretted. It's quiet, it pulls hard, and it will handle an 0-470-50 or 0-550 upgrade with superior cruise over most three blades. It ain't as sexy, but hey, it's a skywagon. :rolleyes: Plus, it shaved nine pounds off the very front C.G. station. A perfect match for our nose heavy ground looper.

It's hard to decide. I've read Grandpa's shtick that the stock 0-470's in the Cessna 18x series have their virtues as well as the intoxicating lust for more power. They burn less, you can keep your auto-gas STC, they run cooler, less weight, and are a cheaper and trusted bullet-proof design that's been tested by time. And they're not THAT much slower in the grand scheme of things. If it ain't broke .. yada yada ...

But I still want more power and speed on tap. Who doesn't? :yes:

Jeff Oslick
June 28th, 2014, 10:33 PM
:confused: How? Valves stick open, not shut. If a valve sticks shut, you will immediately break something in the valve train, usually bending the push rod. Once it happens, you lose that cylinder until repaired. Sticking and burnt valves cause high EGT, not CHT.

We're not seeing a huge increase in CHT here, just about 20F or so at full power. Anything that messes with the F/A ratio can cause a higher CHT. We're (obviously) not certain of the cause, which is why that cylinder is coming off.

Jeff Oslick
June 28th, 2014, 10:38 PM
75°-125° ROP is the absolute worst temp range to run at. Try 150° and see what happens.

125 is as lean as i would run it >75% power. It's not really relevant though, our plane spends very little time over 65% power unless in a climb (where we run quite rich).

Henning
June 29th, 2014, 04:25 AM
We're not seeing a huge increase in CHT here, just about 20F or so at full power. Anything that messes with the F/A ratio can cause a higher CHT. We're (obviously) not certain of the cause, which is why that cylinder is coming off.

Have you checked out the spark plugs?

Ted DuPuis
June 29th, 2014, 07:05 AM
Tagging in because we put an MT prop on our C-180G in anticipation of a PPonk or 0-550 upgrade when it's time. The mating of the two blade MT to the 180 frame I haven't regretted. It's quiet, it pulls hard, and it will handle an 0-470-50 or 0-550 upgrade with superior cruise over most three blades. It ain't as sexy, but hey, it's a skywagon. :rolleyes: Plus, it shaved nine pounds off the very front C.G. station. A perfect match for our nose heavy ground looper.

It's hard to decide. I've read Grandpa's shtick that the stock 0-470's in the Cessna 18x series have their virtues as well as the intoxicating lust for more power. They burn less, you can keep your auto-gas STC, they run cooler, less weight, and are a cheaper and trusted bullet-proof design that's been tested by time. And they're not THAT much slower in the grand scheme of things. If it ain't broke .. yada yada ...

But I still want more power and speed on tap. Who doesn't? :yes:

People make that same sort of argument relative to the 310s and 470s vs. 520/550s. I think for the most part they're right, but the real benefit is for takeoff/climb if you tend to fly hot/heavy or short fields. Twins get the added benefit of better OEI performance. So I think it's a no-brainer. A lot of me wishes we'd done the 550 upgrade in the 310 when we did the engines, but the cost delta of that vs. the 520s was going to be too much to be reasonable, and since the 520s are already 300 HP (just at 2850 RPM instead of 2700), the benefits of the 550s would've been much lower than from the 260 HP 470s to either 520s or 550s.

Skip Miller
June 29th, 2014, 09:18 AM
Hi gang.

Hi back! and welcome!

When is an aircraft engine typically considered to be "broken in"?

Generally "broken in" means your oil consumption has stabilized. It will be higher immediately after new/overhaul, and should subside to a stable level after five or ten hours if you followed proper break-in procedure.

How has your oil consumption been?

-Skip

Henning
June 29th, 2014, 09:44 AM
People make that same sort of argument relative to the 310s and 470s vs. 520/550s. I think for the most part they're right, but the real benefit is for takeoff/climb if you tend to fly hot/heavy or short fields. Twins get the added benefit of better OEI performance. So I think it's a no-brainer. A lot of me wishes we'd done the 550 upgrade in the 310 when we did the engines, but the cost delta of that vs. the 520s was going to be too much to be reasonable, and since the 520s are already 300 HP (just at 2850 RPM instead of 2700), the benefits of the 550s would've been much lower than from the 260 HP 470s to either 520s or 550s.


Yeah, I don't miss the 80hp at the weights I fly at, by 700' I am already 2500rpm and going for 15°LOP climbing nicely enough. Until I can replace with Diesels, I'll keep these 470s running. She just passed annual with no hassles and got a few known squawks worked out. $5500 total. Might have him handle a couple more little projects.

Jeff Oslick
June 29th, 2014, 11:28 AM
Have you checked out the spark plugs?

Read above, they were replaced, and the timing checked.

txflyer
June 29th, 2014, 11:43 AM
People make that same sort of argument relative to the 310s and 470s vs. 520/550s. I think for the most part they're right, but the real benefit is for takeoff/climb if you tend to fly hot/heavy or short fields. Twins get the added benefit of better OEI performance. So I think it's a no-brainer. A lot of me wishes we'd done the 550 upgrade in the 310 when we did the engines, but the cost delta of that vs. the 520s was going to be too much to be reasonable, and since the 520s are already 300 HP (just at 2850 RPM instead of 2700), the benefits of the 550s would've been much lower than from the 260 HP 470s to either 520s or 550s.


The 550 upgrade is an involved and much more complicated install compared to the Pponk upgrade from what I read.

Fuel pumps must be installed for the 550 with return lines. The good ol' Cessna gravity feed system that is so simple and reliable is gone.

And the cost is 100% different. The 550's can cost upwards of $60,000.00 to convert, while the PPonk can be had all day long for half that. I'm preaching to the choir, but you better either have oil wells or have some serious flying to do to warrant a $60K engine upgrade on a $100K bird.

Henning
June 29th, 2014, 11:54 AM
Read above, they were replaced, and the timing checked.

Injector plugged?

Jeff Oslick
June 29th, 2014, 01:29 PM
Injector plugged?

Carbed. Induction lines already checked. Only other thing I can imagine is a compromised ignition wire. Our current harness has around 7 years and 1,100 hours on it, so that is certainly possible.

Jeff

Henning
June 29th, 2014, 01:36 PM
Carbed. Induction lines already checked. Only other thing I can imagine is a compromised ignition wire. Our current harness has around 7 years and 1,100 hours on it, so that is certainly possible.

Jeff

Yep, a bad wire can cause this. I would do a bore scope inspection on the cyl before pulling it. If there is something wrong with the jug that is starting to make it run hotter, you'll see evidence of it.

Another thing to check is valve/ cam lift. If the exhaust lobe is giving up or pushrod worn/bent, that will bring up the CHT in that cyl.

Jeff Oslick
June 29th, 2014, 02:10 PM
Yep, a bad wire can cause this. I would do a bore scope inspection on the cyl before pulling it. If there is something wrong with the jug that is starting to make it run hotter, you'll see evidence of it.

Another thing to check is valve/ cam lift. If the exhaust lobe is giving up or pushrod worn/bent, that will bring up the CHT in that cyl.

Was borescoped a few weeks ago. Nothing obvious, but the borescope setup used was less than ideal. Will be done again before pulling. Again, this is a fairly subtle issue that anyone without closely monitored CHTs would likely never see until the problem got ugly.

FlyingBob
June 29th, 2014, 09:16 PM
Hi back! and welcome!



Generally "broken in" means your oil consumption has stabilized. It will be higher immediately after new/overhaul, and should subside to a stable level after five or ten hours if you followed proper break-in procedure.

How has your oil consumption been?

-Skip

I haven't flown more than 20hrs yet since owning it, so no oil consumption yet.

FlyingBob
June 29th, 2014, 09:19 PM
Yeah, I don't miss the 80hp at the weights I fly at, by 700' I am already 2500rpm and going for 15°LOP climbing nicely enough. Until I can replace with Diesels, I'll keep these 470s running. She just passed annual with no hassles and got a few known squawks worked out. $5500 total. Might have him handle a couple more little projects.

$5500 for an annual? Holy, what did your A&P do?

Ted DuPuis
June 29th, 2014, 10:19 PM
The 550 upgrade is an involved and much more complicated install compared to the Pponk upgrade from what I read.

Fuel pumps must be installed for the 550 with return lines. The good ol' Cessna gravity feed system that is so simple and reliable is gone.

And the cost is 100% different. The 550's can cost upwards of $60,000.00 to convert, while the PPonk can be had all day long for half that. I'm preaching to the choir, but you better either have oil wells or have some serious flying to do to warrant a $60K engine upgrade on a $100K bird.

Agreed, for that price difference the PPonk makes far more sense than the 550 conversion. I'm not familiar with the different options on that airframe since it's not one I deal with much.

On the 310, current prices for the 520 and 550 conversions are the same. The difference is that the 520 conversion came out first, and most converted 310s have 520s. Rs are a different story, but they came with 520s from the factory.

The issue is that, even though there's really nothing different besides the engines on the 520/550 conversion, they won't give you a "returning customer" discount, so basically to go from 520s to 550s you're shelling out as much as from 470s to 550s.

And then that gets into that $120k to put into an $80k bird deal...

txflyer
June 30th, 2014, 01:32 AM
Agreed, for that price difference the PPonk makes far more sense than the 550 conversion. I'm not familiar with the different options on that airframe since it's not one I deal with much.

On the 310, current prices for the 520 and 550 conversions are the same. The difference is that the 520 conversion came out first, and most converted 310s have 520s. Rs are a different story, but they came with 520s from the factory.

The issue is that, even though there's really nothing different besides the engines on the 520/550 conversion, they won't give you a "returning customer" discount, so basically to go from 520s to 550s you're shelling out as much as from 470s to 550s.

And then that gets into that $120k to put into an $80k bird deal...



I know on the 18x frames, the 550 upgrade I think I read requires a new beefier engine frame, mounts, and some cowl work. Along with all the fuel line re-working. So, it's not near as plug and play as the 0-470-50 upgrade.

And then of coarse every 550 must have GAMIjectors and an engine analyzer so you can go LOP to wring every drop of go juice out of that chunk of gold you just installed up front. As if to say, " hey! look! I'm saving money! :lol:

$30,000.00 will buy a lot of Avgas. That's the going price of an 0-550 upgrade over a Ponk on a 180 today. :dunno: