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Cessna 180

WSH

I've read the Service Bulletin. Are the low compression readings related to the O-470-U and is it due to the different pistons with steel ring lands they used in the U model?

Also can someone tell me how does the differential pressure tester with the Master Orifice Tool discussed in the S.B. work? How is it different?

It's my understanding the O-470-U was used from 1977 to 1981 when they quit building the 180 and it was a higher compression engine that ran at a lower (2400) rpm.
 
Mike

I have never heard that before and don't know the answer but I'm looking into now with the Cessna Pilot Association and will report back what I find.
 
Also can someone tell me how does the differential pressure tester with the Master Orifice Tool discussed in the S.B. work?
Click to expand...
I have one of those things and if I remember right, you hook it up to your differential tester and see what number you come up with and as long as your airplane cylinder is as good or better, you pass the test unless it's clearly going out the exhaust.
 
gbflyer said:
You guys are going to get me talked into buying one of those worry meters yet. :D

gb
Click to expand...


Why on earth anyone would like to save money and enhance their own safety is beyond me! :eek:
 
I'd think it's unusual that the valve stem/guide wears, gets sloppy, and the valve continues to seat properly. However, I don't have one shred scientific data to back that up, just my own anecdotal evidence. Clearly it can and does happen.
Click to expand...

Who knows, maybe that valve was seating most of the time and just not at compression test time. I didn't have six cylinder data to compare when running. I still have that valve and it looks usable----the guy in Omaha did a grind job on it before miking the stem and finding it was like an hour glass.
 
Skip,

Do you have any evidence or data that suggests engine monitors have improved aircraft fatality accident rates or general safety? I haven't seen any such report. Or any report that suggests reaching TBO is enhanced by monitors. Or that maintenance costs are reduced. Are there any objective reports out there?

The original question wasn't addressing instrumentation. Instrumentation will not prevent the common maladies that 0-470s experience. They may help the pilot identify them. That's a different topic in my book.

SB
 
[quoteWhen you fail to make products that meet established standards, re-write the standards.[/quote]


Or, just possibly, when the old "standards" have been found to be a poor measure, then a new standard is required. The alternative is of course to never learn anything from our mistakes or any new information and change, just continue to adhere to the old sub-"standards" because, that's the way we always did it. :lol:
 
Yet TCM cylinders met their own standards for decades. The standards weren't changed until their new cylinders started failing in epidemic proportions. You can operate your 50psi cylinders as you wish. I'll repair mine.

What about the question regarding evidence that bar graph analyzers improve safety? I'm genuinely interested.

SB
 
Stewart,

No, I don't have any scientific evidence, one way or the other, that engine monitors, do or do not, improve safety. However, the anecdotal evidence is rather overwhelming that they do help find little problems before they turn into big ones. Now what one does with this information is entirely up to them.

Does your oil temperature/pressure gauge enhance safety?

Many would think finding a problem early is a good thing and in turn would enhance safety, save money, apparently you don't?

Well, You can change your cylinders when they drop below 79 if you like, it's your airplane. For me, I'll continue to save my money and spend it only when it's necessary, on a real problem, not imagined ones.
 
Skip,

I'll wait for that evidence. Meanwhile, as my original post said, the two major issues with 0-470s will continue to happen and will, with or without your instrument, require repair. As for my desire to repair cylinders that may be deemed "legal"? Guilty as charged. I'll spend the money to repair them. With respect to my engines I will not be satisfied with minimum standards of compliance. The top of the scale is what I demand. If you believe there is no difference? Like I said, run yours as you wish. But let me ask you, if you need a replacement cylinder, would you consider a 50psi cylinder of equal value to a 79psi cylinder? If you bought a reman engine and all cylinders showed 50psi after 100 hours would you be satisfied? Be honest.

Some may think I'm opposed to bar graphs. Nothing could be further from the truth. I just recognize their flaws and limitations. I do not think those who don't incorporate them into their panels are reckless or irresponsible. For what it's worth I have a JPI EDM-700 sitting at Merrill Field Instruments with my name on it. It will accompany three Aerospace Logic instruments into my 180's new panel and will eliminate all the stock gauges on the right side. Why the JPI? Because I can replace my current 7 instruments with 4 new ones that are approved as primary replacements. I'll have TC required info plus additional desired info, all displayed in a pleasing and consistent way.

SB
 
Stewart,

[/quote] As for my desire to repair cylinders that may be deemed "legal"? Guilty as charged. I'll spend the money to repair them. With respect to my engines I will not be satisfied with minimum standards of compliance. The top of the scale is what I demand. If you believe there is no difference? Like I said, run yours as you wish. But let me ask you, if you need a replacement cylinder, would you consider a 50psi cylinder of equal value to a 79psi cylinder? If you bought a reman engine and all cylinders showed 50psi after 100 hours would you be satisfied? Be honest.
Your good at asking questions, when are you going to start answering some?

As for this latest question, of course I'd want the higher compression cylinder but that isn't the point and you know it.

Once you own the cylinder and it's on the engine, when does it become a safety/performance issue?

If you demand "Top of the Scale" as you say you do, they when do you pull the plug on a cylinder? "Top of the scale" suggest nothing less than 80/80 will do for you. That's the top of the scale, 80, maybe it's a floating scale for you?

Since you seem to know more about the subject than TCM and why they came out with the newer limits in the SB03-3, please enlighten us and tell us all what that limit should now be and why?
Click to expand...
 
My experience the day I pulled off an airworthy 0-470 with compressions in the low 60s and replaced it with a new engine with compression near perfect? There was absolutely no question that the new engine spanked the old one in every power-related parameter. Absolutely no question. And yet the new engine was expected to improve on power as the bearings and cylinders ran in.

When I had one cylinder drop into the low 60s a couple of years ago the issue was announced to me by a new vibration and reduced cruise speeds. Since my TO weights are always changing I never really noticed TO performance degradation. Once that cylinder was repaired the vibration ceased and normal cruise speeds returned. In fact I've had that experience twice with my current engine. Neither cylinder was required to be repaired using the new TCM standards. I don't regret doing so.

On what my personal limits are? It depends on how we got there. I become uncomfortable with compressions in a single cylinder deviating from the rest. That's what I've experienced. If I have 5 in the 75-76-77 range and one in the mid or low-60s? It's coming off. See the pirep on single cylinder repairs above.

Does that help explain my attitude? What questions have I failed to answer?

Stewart
 
cessna 180

mvivion, an old pilot friend of mine always rinsed his engines with diesel fuel until they ran clear after his oil changes, everything from cubs to 414's, i have been doing the same for 12 years
 
Stewart,

I've heard that story before and I believe, you believe that. The science, and there is a study and data on this, suggest otherwise. I can't point you directly to the studies finding, however, IIRC, Mike Busch and the GAMI guys have talked about and I trust their opinion and am going with it as fact. If you have any data to the contrary, I'd like to see it.


I've replaced cylinders, one at time, two at a time, even topped an 0300 with all new cylinder and didn't see one bit of improvement. None, zero. I'd say what you experienced was a "placebo" effect. I am sure you feel otherwise but, to use an old APS quote, "the data doesn't lie".

You said TCM changed the standard because they couldn't meet the old one anymore. Do you have proof of this or is that just your opinion?
 
Sorry Skip, but this topic has run it's course. I participated to help answer the original question. I'm done.

SB
 
And for me both of your 0-470 insights have been helpful, since you both have "been there, done that" with TCM, and I have not.

Jim
 
0-470

Thanks for a good discusion. Good timing for me.
I found a 1976 180J, its been sitting since 2003. 1080 TT, no mods, one owner, same hanger, never left out side over night. NDH. Still looks new.

I flew this plane home and did about 8 flights and 8 hours. Did a compresion ck, it had 20/80, 60/80, 72/80, 72/80, 74/80, 70/80, compression. I took the two low ones off and had them reconditioned. Just put the engine back together this evening.
I hope to fly this airplane some before having to take the other four cylnders off. Haven't started it yet. maby tomorrow.
 
OKMike,

okmike said:
What about low compression readings on the later model O-470-U?
I was told the steel ring lands don't seal well under 80# pressure during compression tests but seal OK under combustion pressure.
Is this true?
Click to expand...

This is the response I recieved from Bob Moseley. Bob worked for TCM for some 35 years and was their SE Regional head honcho when he retired. He and his wife now run thier own engine and cylinder shop in Fulton, MO. Skytek I believe.

"Actually, TCM introduced the steel insert in the top compression ring land only due to the fact that wear issues in that area caused low compression readings and the steel insert virtually eliminated those issues. Compression readings are mainly used as a tool to determine engine health, not airworthiness in itself. Piston skirt scuffing is usually caused by overheating if severe, and light scuffing will be noted on the thrust side of the piston which is not a cause of concern. TCM has leaned to less and less choke during manufacturing, and, the issue of choke compatibility of inserted pistons has been a subject of possible concern in years past. However, I can tell you with absolute confidence that .008 taper, (not choke) with an inserted piston works very well with an oversize set of rings fitted to min specs. Taper started about 4" from the bottom of the cylinder. I have also had good luck with compression staying higher longer. With that being said and knowing that compressions have to be understood of what they mean, if the engine runs up to higher times, and many of the TCM's do, it also works."

mose
 
OKMike,

okmike said:
What about low compression readings on the later model O-470-U?
I was told the steel ring lands don't seal well under 80# pressure during compression tests but seal OK under combustion pressure.
Is this true?
Click to expand...

This is the response I recieved from Bob Moseley. Bob worked for TCM for some 35 years and was their SE Regional head honcho when he retired. He and his wife now run thier own engine and cylinder shop in Fulton, MO. Skytek I believe.

"Actually, TCM introduced the steel insert in the top compression ring land only due to the fact that wear issues in that area caused low compression readings and the steel insert virtually eliminated those issues. Compression readings are mainly used as a tool to determine engine health, not airworthiness in itself. Piston skirt scuffing is usually caused by overheating if severe, and light scuffing will be noted on the thrust side of the piston which is not a cause of concern. TCM has leaned to less and less choke during manufacturing, and, the issue of choke compatibility of inserted pistons has been a subject of possible concern in years past. However, I can tell you with absolute confidence that .008 taper, (not choke) with an inserted piston works very well with an oversize set of rings fitted to min specs. Taper started about 4" from the bottom of the cylinder. I have also had good luck with compression staying higher longer. With that being said and knowing that compressions have to be understood of what they mean, if the engine runs up to higher times, and many of the TCM's do, it also works."

mose
 
Hey Jay

Just curious, did you pull all the tappets/lifters?

Find any spalling from sitting for that long?
 
Thanks for the great information
I bought a 79 182 with 1500TT, it has a O-470-U with 150 hrs SMOH w/new Millinimum steel cylinders, the MOH was in 2003 and the plane was only flown 115 hrs SMOH when I got it in late Oct, 2009. I've put 40+ hrs on it and the compression hasn't changed much and is in the low 60's with one at 58 (standard test without master oriifice tool). The engine uses no oil, puts no oil on the belly and has plenty of power. Custom AreoMotive in Tulsa did the MOH and they say it's typical of the U series with the steel ring lands and to just fly it and check it per the TCM S.B.

If I thought someting was wrong I'd have it re-ringed but it runs great and uses no oil so I think I'll just watch it. I've got a trade working with it for a 180 with the O-470-U, and don't know the compression readings on it yet.

Any advice is appreciated concerning the later model O-470-U high compression low RPM engine.

Mike
 
only 2

Could not look at all lifters. Only removed two cylnders.
Had em fixed up and put them back on.
The inside of the engine looks good, from what we can see looking in through #1 qnd #4.
If ? doing this dosent fix it up I will pull the other four. Since this 180 is new to me ,,, I am willing to do the work twice ,,, just to see if I can save a little money. Its only sweat equity.
I had a quart of oil blowing out and coating the belly after each hour of flight.

#1 20/80 had a leaking exhaust valve. #4 60/80 was blowing past the rings.
 
180

My C185 - 520D with over 1500 hours and never touched a millenium cylinder yet [compressions are all in the 70's] carrying heavy loads on floats and doing float training, not a easy life. My 54- C180 - 470-U has over 800 hours on milleniums [ compressions low 60's] float training and solo rentals - great engine with 90" 2 blade mac prop, my C172 - 180hp lyc - ECI's, a few stuck exhaust guides, ream them out and good to go. [compressions 70's] over 2000 hours in 4 years all float training and solo rentals, thousands of take-offs and landings. Fly the heck out of them, sitting is the worst thing!
 
Re: 180

Brian Schanche said:
Fly the heck out of them, sitting is the worst thing!
Click to expand...

Ditto. Looking through the logs on my plane every engine went to tbo and most without pulling a cylinder. The vast majority of the time on my plane was .7 hour trips to the guy's favorite fishing spot every other day.

"top of the green, all day every day" and "cool cylinders and plenty of cool, clean oil."

The only engine that had cylinder problems and needed a top was when it was not flown weekly.
 
I know an engine that sits will get condensation and is likely to start corroding but what would you suggest for an airplane that sits from fall to spring over the winter? When it's on floats and your waiting for spring what's the best thing to do for your engine?

thanks
 
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