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Cessna 180

Scouter

Scouter

SPONSOR
Exeter Maine
I probably should ask this question on the 180 club site, but there is as much knowlege on this site from people who are flying them every day.
What is the key to get a Continental 0-470 to run to close to TBO? I have spent some time looking and researching Cessna 180, and it seems there hasnt been a better time to buy then right now. Most all I have looked at have not come close to TBO without being topped. A lot have been topped at 600-750 hrs. I have a friend here in Maine with a late model 180 that has one soft hole at 400 hrs SMOH, he is sick over it, he takes very good care of his plane as well.
Is the key to run the engine like it is stolen? Or baby at low RPM? I have watched a few local charter guys on floats, and understand that a working float plane with a lot of TO and landings might fall short of TBO without a top. Most of the local ones are weekend flyers that love and baby their planes, but still topping the engines somewhat early at a big expense.

BTW, saw a 180 last weekend, rebuild from a wreck with a 0-520 with 3 blade, the thing was a monster performer, very impressive with a good load. Thanks in advance

Jim
 
I think quality control is lacking. I had an exhaust valve that was shot after 200 hrs. running 100LL only with my O470K. It turned out that whoever ground the angle on the toe of the rocker arm did it wrong but the other 5 were alright. On a little Lycoming, I had a dead cylinder after a year and that was because whoever put the valve seats in didn't drive one in all the way and it moved.
 
I lost a cylinder on my 0320 A2B last winter because of a valve seat that lifted out. Cylinder ate itself nicely. Luckily there was a plowed road within 1/2 mile, but still a bitch to do cylinder removal and later replacement in a snowy field.
My O 470 R is 1350 since major without a top. Monitoring oil and will do a Pponk when indicated. Compressions all >72.
Matt
 
A lot depends on who did the overhaul. Was it operated on floats? Overloaded? Leaned too much? A key seems to be how much cooling air is rammed through the engine. Are the baffles in excellent condition? If it is flown at 110 knots or less, particularly on floats, it will not get enough ram air cooling. You want the CHTs, measured on all 6 cylinders, to be well under 400 degrees for longevity. With low cruising speeds on floats it is not unusual to only get around 700 hours on the top end. My opinion is don't baby it. But how do you know what the previous owner did before he put it up for sale. It would likely be wise to figure the cost of a top in your purchase price.

A good one will treat you well for a long time, without being a maintenance hog, if you treat it well.
 
Well, a Continental O-470 is just not as bulletproof as a Lycoming O-320 or O-360. But flown reasonably and regularly and with shock cooling/heating the first thing in mind, it will last close to its TBO, which is lower than Lycoming. (Presuming a good rebuild.)

A 180 has too much power for the airframe on low drag 8x6 tires; all that horsepower is only necessary for a few short seconds on takeoff. Even relatively high FPM climbs can be at reduced power. This is especially true at the low elevations and cooler temperatures you have in Maine. I run 17-19-23 inches at 2250-2350 rpm in cruise. More power is very little speed gain, and causes a harsh ride in any turbulence, so at comfortable speeds the engine is loafing.

So the next step is to keep the thermal state of the engine constantly in your mind, and this "engine empathy" goes beyond just shock cooling and shock heating. Cruise climbs, gradual descents, and with power on all the way to the ground. You don't need anything more than a single probe egt for mixture control (25-50 ROP), though some guys like the 6 cyl engine analysers to see if one cylinder is too lean. If you are going to deadstick it, cool it at 13 inches of MP and low RPM for several minutes first.

Bob Breeden

www.AlaskaAirpark.com
 
"Pour the coal to it" was the title of a story in one of the top aviation magazines about making and using Continental engines about 35 years ago by the company's boss of engineering. Engines in the half-dozen 180s I owned all went to time, never a top, never a ring off. Maine members here may remember Ed Tardi in Fredericton who ran a good overhaul shop. We watched a 180 being babied after take-off and he said, "Worst thing in the world for engines."
 
cessna 180

That story escaped from my files years ago. I remember it had a two-page photo of the Continental assembly line over the lead to the story. Seems also that the engineering chief said that for quality control an engine is taken from the line and run wide open for 12 minutes, stripped down and everything has to be within new limits. The quote I remember from him was something like there was more full throttle time on the engine before it left the factory than the pilot would use for years.
 
The O-470, perhaps more than any other engine, can really use a six cylinder engine analyzer to stay healthy. It really helps to be able to see CHT and EGT on EACH cylinder at all times.

The mixture distribution on these big engines is about as uneven as it gets, and the distribution changes with different power settings.

A good graphic engine analyzer and a pilot who pays attention to temperatures will take an O-470 to tbo with little interim maintenance.

MTV
 
When I bought my 180 it had 87 hurs on a major done by the guy that used to build them for Kenmore. It is now pushing 1700 hours and I had to replace one exhaust guide so far, the rest of the cylinders have not been off. My procedure is to use takeoff power only as long as needed, and normaly cruse at 20 inches or less at 2200 RPM. My plane has an engine moniter and I climb 100* rich of peake and cruse at peake on number 3, my hottest cyclinder, usually burning 10.5 gph and trueing 135K at altitude. So in my experiance having an engine that is put together properly, watching the tempitures, and babying it is the way to go, which is what most of the above seem to be saying............
 
This question came up a few years ago and what I found out was the manufactures of these enjines recommend to reach TBO, that they are to be flowen every 48 hours, up to temperature,meaning, 1hour duration,to burn any moisture, , change oil as recommended. Not everyone can afford to fly like this nowadays.
 
Start with new cylinders, run it hard, run it often, and run plenty of gas through it. I've heard that MMO is good. This is with 100LL, never had a good source for clean car gas, that also might help. I never had any trouble until I started babying it. That is after owning 3 O470's, a -J, -L, and a -K.

Opinions vary. Seems like if you get a good one, you can do anything to it.

gb
 
I took mine to TBO running car gas, 100LL (and a little Marvel) by watching the cyl head temps closely.

I flew it oversquare much of its life, but had the 0470S engine.
 
I didn't mention that when I bought my 180 it had been sitting most of the time for 15 years and only had 87 hours. I've put the rest on with few trips over an hour, most 15 minutes just bouncing around the islands. Keep it cool, run it easy, save on gas........
 
The one I fly has 2400 hours on it, and the cylinders feel the same as they did a thousand hours ago. We run it at 10 gph.
 
My 1953 Cessna 180 sports a O-470A that has over 1650 hrs on it. It runs like a champ with all compression in the 70s. I have only owned it for 10 months and have put 150hrs on it so not sure how it was flown prior to me. I have to been told to run it like a bat out of hell, which I have done. I have also been told by a good friend that has had one since the 60s to run them at 2350rpm and 17" MP. I do both, it seems to like it either way.
 
Good Question,
Lot's of opinions.

Mine is over TBO, never had a jug off. Most times it only needs a quart of
oil in 20 hours. Good compression, very happy with it. It has been run
with heavy loads, on skis, (no floats :cry: ) Many hours low and slow
on wild life surveys. Some days I cruise at 2400 and max MP, other days
I loaf along with 19in MAP and 2200 rpm. (indecision may or may not
be my problem).

I change the oil at 25 hours. wish I had a fliter so I could go 50 hours,
but then would I have such a good motor..?

The 180 is a great airplane, get a good one, you'll love it.

In another thread, it was mentioned "running 2000 rpm and squared
or lower MAP...." (fuel economy) Is there not a lower redline on the tach...? such as for
harmonic vibrations and what not...? I think on mine it is 2200...???
I must look tomorrow. I did try it, the 2000 rpm and 19in MAP thing
a while back... it was slower going, still got there, have no idea what
gph I had, (fuel tank has no working guage).
Good luck and have fun..!

kem
 
The book on my 470L shows a best economy power setting of 18 inches and 2000 RPM. I use it sometimes if I'm not in a hury and don't have sugnificant headwind. It seems like it burns about 8 gph and makes about 100K..........
 
Our 180 is a 76 and we have had it since 79 with 300 hours on it. We run it on floats in the summer and skiis and wheels in the winter. A lot of full throttle time especially in the summer on floats. The engine is an O-470-S. We went 200 hours past TBO without haveing to go into the engine at all. No valves, no cylinders, no top work. We don't always fly it regularly. Sometimes it sits for 2 months without flying. I was also doing 100 hour oil changes with oil analysis (changed that after the overhaul). We do have a graphic engine monitor of egt and cht on all six simultaneously and we monitor it constantly. The engine is very smooth and at overhaul I paid to have it balanced and blueprinted so it is still very smooth. We do pay very close attention to engine thermal cycles as mentioned in the above responses, and plan well ahead and make no more than 3" mp power changes about every 2 or three minutes. We have an oil dilution button on the dash if anybody remembers that and I use it at every oil change to dilute the oil and I get a better oil drain and clean out all the galleries too. We have a 500 gallon gas tank for fueling on floats with auto fuel and we put Mystery oil in the gas when it is delivered so it gets a constant diet of that at least half of the year. I started running autofuel before the STC came out in one tank and we have had no problems. We use the no alcohol premium. Not sure what the formula is but that has been my experience. Our engine has been very good to us!
Captain Ron
8)
 
Thanks everyone, great responses. Capt ron, can you explain the dilution button a little bit? Does that mix avgas with the engine oil? You do it only at at oil change I suppose.

Jim
 
skywagon8a said:
If it is flown at 110 knots or less, particularly on floats, it will not get enough ram air cooling.
Click to expand...

I should clarify this statement which I made. This situation is only likely to occur if you are flying on floats with HEAVY loads and high power settings to keep it moving. If you are lightly or normally loaded you will not need the high power, with the low speed result.

Be very careful with a rebuilt wreck. There is nothing wrong with getting a rebuilt, just be very careful. Some are better than new. And, there are some who do a beautiful job of rebuilding wrecks except that they are not put back together straight and will never fly correctly. It can be extremely difficult to find the errors. I have seen one of these both before and after. It did not fly straight. It took a lot of time to find what was wrong. ( The cabin top was put on crooked ). The seller had to take it back. I don't know where it is now. Scouter- This plane came from Maine. I will not reveal who the perpetrator is on line. He has a reputation. You likely know who it is. :bad-words:
 
Reading all this, you've stirred the juices and I have to say the 180 is the best aircraft I've owned. The Cubs set me up for perfection. I sure knew it when I saw it. The 180 doesn't fit my missions now but if I had the money I'd buy one and steal the money to fly it. The 180s had everything.
 
Scouter,

Many airplanes which were destined for the far north were equipped with an oil dilution system. The way the system was INTENDED to be used is that prior to shutdown, when the airplane is to be parked out in very cold weather, you'd use the dilution system to introduce gasoline into the oil system. This thinned the oil, and thus made cold starts easier.

After the next start, the avgas cooks off from the oil fairly quickly.

I think everyone agrees that preheat is a better idea. Never heard of using it prior to oil drain, but....why not?

Many Beavers, 180's and 185's came equipped with oil dilution.

MTV
 
MTV is exactly correct. I heard they don't even offer the dilution button anymore. We rarely used it for that and now that we have the preheat system on it, I only use it at oil drain time. I think the good cleaning it gets and the smoothness of a balanced engine and the attention to thermal cycling has had a positive effect on my engine but I do not know if that is the definitive reasons. I have heard that using unleaded gas has a big positive effect on maintenance costs over the life of the engine also but don't have any way to evaluate that statement.
Captain Ron
8)
 
mvivion said:
Scouter,

Many airplanes which were destined for the far north were equipped with an oil dilution system. The way the system was INTENDED to be used is that prior to shutdown, when the airplane is to be parked out in very cold weather, you'd use the dilution system to introduce gasoline into the oil system. This thinned the oil, and thus made cold starts easier.

After the next start, the avgas cooks off from the oil fairly quickly.

I think everyone agrees that preheat is a better idea. Never heard of using it prior to oil drain, but....why not?

Many Beavers, 180's and 185's came equipped with oil dilution.

MTV
Click to expand...

Hmm. I never knew there was such a thing as oil dilution.

Thanks for sharing that.

Tim
 
The two items that have bit me with my 0-470s have nothing to do with operating technique or instrumentation. The average 0-470 will suffer from valve guide problems. That's well known. Through the years valve guide materials have improved. Many still fail. The cause in my experience has been poor rocker arm geometry. That problem can be corrected by a good cylinder shop. The other problem is the rubber induction connectors. Keep them tight and inspect them regularly. Big problems can come from little leaks.

SB
 
Stewart,

StewartB said:
The two items that have bit me with my 0-470s have nothing to do with operating technique or instrumentation. The average 0-470 will suffer from valve guide problems. That's well known. Through the years valve guide materials have improved. Many still fail. The cause in my experience has been poor rocker arm geometry. That problem can be corrected by a good cylinder shop. The other problem is the rubber induction connectors. Keep them tight and inspect them regularly. Big problems can come from little leaks.

SB
Click to expand...

This is not directed to you as I already know your view on the subject, just a general comment for anyone lurking.

Both of those problems can usually be caught early with the proper use of a multipoint engine monitor.

Worn vale guides start showing up as jittery EGT readings as the valve /seat interface starts getting sloppy and begin to leak. There is generally about a 20-25 hour window from when a valve starts to show signs of a problem to the point of failure. With a engine monitor, you can usually see the problem starting, long before the valve actually burns to the point of failure, i.e. swallowing a valve.

Induction leaks show up immediately on the monitor as abnormally high EGT and CHT's. With the factory single point CHT gauge you could be cruising a long, fat, dumb and happy literally burning up the other 5 cylinders and be completely clueless until the damage is done.

There is no logical reason not to have a multipoint engine monitor today. They pay for themselves by catching "little" problems before they turn into "big" ones. By simply finding an induction leak early before burning a couple of cylinders or a burning valve before it fails while " on the road" in the middle of nowhere, you have saved enough to pay for the monitor.

What else can you put in your airplane that enhances safety and ends up paying for itself?
 
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?
 
Mike,

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...

In general, the static compression test is a poor indicator of a cylinders overall health. It's all we had before so, we're still hanging on onto it as the "Gold standard". There are better ways to judge a cylinders health today.

Have you seen/read this?

http://www.tcmlink.com/pdf2/SB03-3.pdf


A combustion event can generate 800-1000+ PSI. Rings and valves that leak at 80 PSI won't necessarily leak at 800-1000 PSI. With TCM cylinders somewhere in the mid-40's is acceptable.

There was a test done sometime ago where they ran an engine on a dyno with steadily decreasing compressions. The engine continued to make rated power all the way down to Zero static compression. They even did without rings, and it still made rated power! They just couldn't keep enough oil in it to keep it running for very long. :lol:
 
There is generally about a 20-25 hour window from when a valve starts to show signs of a problem to the point of failure.
Click to expand...

You are most likely right but my experience was a little different. Majored engine in 1995 and ran it on 100LL exclusively for 200 hours and number 1 cylinder is 30ish/80 compression leaking past exhaust valve. IA says to run a while longer so I start using auto gas and after a little while comp. comes back to mid 50's. Thinking things are getting better run it for most of another 200 hr's and end up at less than 10/80 so pull cylinder and find exhaust valve stem is worn funny even though where it touchs the valve seat isn't too bad---not really burned. Valve guide is shot also because of the geometry thing Stewart talks about.
 
Marty,

180Marty said:
There is generally about a 20-25 hour window from when a valve starts to show signs of a problem to the point of failure.
Click to expand...

You are most likely right but my experience was a little different. Majored engine in 1995 and ran it on 100LL exclusively for 200 hours and number 1 cylinder is 30ish/80 compression leaking past exhaust valve. IA says to run a while longer so I start using auto gas and after a little while comp. comes back to mid 50's. Thinking things are getting better run it for most of another 200 hr's and end up at less than 10/80 so pull cylinder and find exhaust valve stem is worn funny even though where it touchs the valve seat isn't too bad---not really burned. Valve guide is shot also because of the geometry thing Stewart talks about.
Click to expand...

Roger that.

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.

And, I should and need to clarify my "20-25 hour window" statement a little. I meant that the "window" is AFTER the telltale signs start to show up on the monitor. The reality is, some go much longer before failing, some won't go as far, however, the valve has already started to fail/burn before the symptoms are severe enough to show up on the monitor. If that makes sense?
 
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