I'm just coming off a lycoming 0-540 and going to a continental 0-520 (Texas Skyways conversion). I read so much about how reliable 0-540's are (and I never had a spec of trouble with mine - engine had 1500 hours on it and had never been touched) and I also dont think ive seen too many continentals that make 1000 without the top being done as a minimum. I've heard you need to watch overcooling the continentals when pulling the power. Can anyone tell me why the continentals seem this way and some pointers so i operate mine in a manner that will protect the engine as best i can?

garth

I sure wish I knew Garth. I'll be watching your thread for answers. I've always heard the same sorts of things. Heavy case this and that etc. I notice that most big Continental powered airplanes come up for sale at or near 1200 hours SMOH.

So Garth, why did you switch??

The IO-520s being operated by ham fisted aviators have given big Continentals a bit of a bad rap. One of the problems with the IO 520 is that takeoff rpm is 2850, and that's putting a lot of stress on those engines.

I know of operators in AK who operate IO 520s day in and day out, and take them to TBO all the time, often without changing a cylinder. The O-470 engines are bullet proof as any 180/182/Bonanza owner will tell you. TBO isnt' quite as high as Lycoming, but.....prices aren't either.

I once had a very similar discussion with a Lycoming tech rep, and his response was that he was pretty confident that Continentals are just as reliable in almost ever regard as Lycomings, all in all.

The big hoo haw over crankshafts in the big Continentals a while back?? Guess what--Lycoming uses the same supplier of crankshaft blanks, and had the same issue...They were just lucky enough to catch every one of the engines they built with those cranks before they were delivered to customers and fixed them. Quietly.

If you're going to run a 520 as a carbureted engine, you'll be running MUCH lower rpm at takeoff, like 2700, and I'd bet you'll find that engine will easily run reliably to 2000 hours.

But remember--the single biggest killer of engines is non-use. Let that thing sit in a hangar, fly it ten hours a year, and good luck.

As to shock cooling being responsible for cracking cylinders, I've been told by a couple of good engine experts that this is mostly a fairy tale, and when it DOES happen, or appears to happen, it's associated with engines that have cylinders that are VERY old, work hardened, and should have been trashed decades ago. I've seen Continental cylinders that were multiple runs, and literally decades old. This is specifically why Lycoming will not salvage ANY cylinder that comes into their plant for rebuild.

I'm not suggesting you should close the throttle in cold temps, and run it at idle in a rapid 4000 foot descent....you do have to apply a little common sense, after all.

Cylinders are tapered toward the tops. As the engine heats up, the head and top of the cylinder "grows" a bit due to heat. Pull the power off, and descend a long ways in cold air and you can change the choke of the cylinder.

BUT, the biggest issue with running long, idle power descents is that the propeller is now driving the engine, as opposed to the other way around, and THAT isn't real good for the engine. However, even that won't crack cylinders.

MTV

Speaking of Continentals... 3 hours ago, we just got back from picking up an E225, that was running when taken off for a re-power. 300 hours since major, but sat for 4 years? Also got an E185 case, crank, rods, etc thrown in, all for $450. My friend is putting it on his air boat.

The question...can a guy find an adapter to turn the spline crank into a flange for a standard propeller??

patrol guy wrote:So Garth, why did you switch??

Good question - i'm selling my maule (0-540) because i bought a 182 with a Texas Skyways 0-520. Im in no way regretting any of this but i was just curious. The AME where I bought the plane, told me that Continental has bullet proof bottom ends, but not so much on the top, and he said lycomings have bullet proof tops, but not so much on the bottom. He said the ideal motor would be a continental bottom end with a lycoming top.

when i was doing my research before buying, most 182's (that have continentals) seemed to list work done on the top end. , hence the question. I'm not real worried about it, and plan to fly mine regularly. The Texas skyways conversion is actually good for 2500 TBO, and mine had just over 600 hours on it, and the top was done just before i bought it so i'm hoping i should be good for a while.

garth

mtv wrote:Cylinders are tapered toward the tops. As the engine heats up, the head and top of the cylinder "grows" a bit due to heat. Pull the power off, and descend a long ways in cold air and you can change the choke of the cylinder.

MTV

How can I phrase this so as to not get anyone in trouble here. Hhmmph. The mechanic who used to work on my Mooney at the main FBO at San Carlos California had at one time worked for a well known, now defunkt, engine shop on The Bay a little further south. This was a big shop, specializing in big Continentals, big ad in TAP etc. He told me he found out that the shop had set up their cylinder hone to take out all the choke in the cylinders. He raised hell. He left their employ. It seems word got around about that and other issues and the shop went TU. New cylinders are best usually eh? Makes sense to me, unless you are positive that they are being machined right.

It's a bit like the recent revelations on this board about cam and tappet machining. Hard to believe that you can hang a shingle that says "engine shop" and be that misinformed about your product. In the case cited above, the hone machine was an automotive unit apparently. For water cooled engines. Cheaper. Beyond that I cannot say.

mtv wrote:The IO-520s being operated by ham fisted aviators have given big Continentals a bit of a bad rap. One of the problems with the IO 520 is that takeoff rpm is 2850, and that's putting a lot of stress on those engines.

They run 2850 to get 300 HP. I know Cessna used them in 185's and 210's for that purpose, others may have as well. Beech did not in the Bonanza. Power was limited to 285 HP at 2700 RPM. The main problem we see in the Beech community is Continentals inability to properly make and install a valve guide. The ECI's and Milleniums don't have this problem.

So in short the Lyc is more forgiving to abuse?

motoadve wrote:So in short the Lyc is more forgiving to abuse?

Not at all. NO engine is built to take a lot of abuse, though most aircraft engines are pretty tolerant.

BM,

You're correct. Beech chose to run the IO 520 at 285 hp instead of trying to drag 300 hp out of it, and as a consequence they have had many fewer problems with those engines.

I'm sure all other Continental issues will be corrected, now that the Chinese own the company......

MTV

When I had my 470 overhauled the advice I got was if I put new Continental cylinders on it I could reasonably expect them to go about half way to TBO. Milleniums could be expected to go all the way to TBO. Greater upfront cost but lower long term cost. No idea what Millenium availability is now given what Superior has been through or if their products will change with the new owners.

Ya and ECIs can be expected to go half way to your destination!

ccurrie wrote:Ya and ECIs can be expected to go half way to your destination!

They'll at least get you to the scene of the crash. Just kidding.

wasn't a crash just two forced landings in 300 miles then a new engine later on .

I haven't had any reliability problems with my o-470s or 0-520. I have had a couple of exhaust valves need attention and learned that big TCM cylinder valve guide wear, and subsequent valve leakage, is usually attributed to off-center rocker arm contact with the valve. Mine were corrected and it's been happy days since. And for what it's worth, the geometry problem isn't limited to one brand of cylinder.

As for the RPM comment, if you read the PPonk service letters regarding higher compression cylinders and higher than 2700 rpm issues, they specifically discuss o-470 cranks and bearings. So what about those of us with IO-520 cranks? I had a bad tach that had my engine spinning at 2900 at take-off for some time before the error was discovered. Man, that thing performed well. Still does at the legal limits, but the stories some guys tell about these engines pulling harder at 2700 that at higher speeds are bunk in my opinion. I liked the high rpm performance, but these days the gravel dings have slowed down and that's a welcome change. Historically the TCM cylinder failures in IO-520s were from cracks. But those engines are high compression, too. Not many TSIO-520s around here. I wonder if they had the same problem (lower compression). Then they changed their hone procedures in all their engines and compressions sagged prematurely. These days you don't hear much about those problems. Now TCM cylinders are the ones without one run life limits like the Milleniums and ECIs have. Perfect. After guys like me went aftermarket to avoid the TCM headaches. Who'd have guessed? Aren't airplane engines fun?

I can't offer decades of technical background, I can only offer another data point. In April of 1996 I had a Lycoming IO-360-A1A crankshaft shear in half while flying straight and level at 14,500 over Green River, UT . I glided 17 miles and put her down with out a scratch .

Currently I am flying a Continental PPONK converted 0-470-50 in my 182B. I don't know how to explain it but I feel really comfortable while flying in the backcountry with that big Continental out front.

I currently have the sheared portion of the lycoming crankshaft sitting on my desk at work. Some friends of mine fabricated it into a pencil holder. So when I think I am having a bad day at work.......

The Lycoming 0-540's that are not asked to produce 300+ horsepower probably have the best reputation of all the big bore engines. They are overbuilt for the simple task of producing 230, 250 or 260hp. Everyone talks about this series of engines as being bullet-proof reliable which is well deserved, but the I0-540's that produce big hp and have turbos installed have similar reliability to the big Continentals.

My brother in law has flown thousands of hours in 402's and Navajo's and always said the Lycomings were always less temperamental but they flogged all of their motors and generally had similar reliability. He wouldn't worry about who's name was stamped on the cases as much as how they were overhauled and flown.

Many overhaul shops report that crankcase cracking problems with TCM (360 vs 470 vs 520) engines are usually proportional to horsepower, more power more cracks. However, the 520 engines have front mounted, gear driven alternators. They tend to break and shed parts into the engine, which could be bad news . The 470's have a rear mounted, belt driven, alternator that won't ruin your engine. The P-Ponk option looks better all the time.

There are no absolutes when it come to engines though. Any can fail in the hands of humans. Fly often, as was mentioned above.

I spoke to my hangar neighbor yesterday who owns a Turbo Arrow. The manual wastegate TSIO-360 installed in his plane is one of the most pissed-off and miserable engines in GA...cylinders cracking, oil leaks, loss of compression, cracked cases, turbos that grenade..bad rep-
He installed a factory reman in 2000 and reported that he now has 1480 completely trouble-free hours. Who would have thought? That restores my faith that diligent engine management and smart piloting can make any engine last.

SixTwoLeemer has it exactly right! I've never really noticed a big "brand" trend in reliability as much as an "expectation".
The "Turbo Edsel" can be a real pig about cylinders! We had 3 of them of our own and took care of 4 more as well as 2 Seneca II's (same engine) and they were all real cylinder hogs....until we started paying alot of attention to baffels and cooling, as well as beating pilots over the heads with operation procedures!
Any engine's reliability goes down just a bit when you ask the same cubes to produce more power...that's sure no secret. That's also not saying that it can't be done, and with good reliability...it just takes a bit of work and care.
John

I premise this by saying I am knocking so hard on the wooden table that it is shaking.

Our normal run is thee villages out and back in one hour. 15 minutes to the first one, six to second, three to third, back to second and back to first and then home. That is six starts, six take offs and six landings. We are now on our short schedule due to daylight (lack thereof) and run that route 8 times a day.

We get some strong winds, those combined with the mountains make for strong down drafts on final at two of the airports ie full throttle and off...fast. Our schedule is tight, so it is start to full throttle within 60 seconds max. We get cold here but not interior Alaska cold for us -10 on cold cold days, winter is usually around 20s. In other words, the flying we do is the definition of a ham fisted, hot-to-cold, cold-to-hot, engine-abusing operations.

I have now around 3500 hours flying these 206s and have lost one cylinder (the table is now about to break). I came into the Continental with the same mis-conceptions that they would not take the abuse that a lycoming, however, I am now a true believer in the IO-520 (knock, knock, knock). Having said that, we are on a 50 hour maintenance cycle so they do get a lot of good loving.