Big Continental engine reliability

woxof

Pre-takeoff checklist
Joined
May 6, 2015
Messages
124
Display Name

Display name:
woxof
Someone on another forum wrote this which I found interesting. Is this pretty much your take on things?

"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."
 
Probably true, in all.

Kinda like voting for either party... In the end, the politicians are all the same.

Not intended to be political. Just analogous...

Ford/Chevy/Mopar same deal. In the end they all last as long as they're treated well.

But boy, can we argue about the differences, can't we?
 
Someone on another forum wrote this which I found interesting. Is this pretty much your take on things?

No. I neither agree with the statements, nor do I subscribe to the false equivalence of all GA engines are equally reliable. But, it doesn't matter, because of captive audience. If we could swap engines like the EAB guys, this would be much less of a head-in-sand dynamic. Stockholm Syndrome abounds on this topic. The industry doesn't really care, as they're not incurring the expense of crappy design re-formulation, nor do they have to in present circumstances.
 
I question everything but especially this: "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".

Where is the proof? The analysis? True in all climates or just in certain climates? I may not fly at all this year or just a couple of hours because no where to fly to since everything is pretty much shut down but I don't think this is going to affect my engine life here in the ultra low humidity of the Arizona highlands. I especially question the logic of flying around in circles putting extra hours on your engine and consuming all that AVGAS unless you just want to fly around in circles.
 
If you've been around big Continentals for 30 years you've seen their poor cylinder honing, 520 cylinder cracking near the injector bosses, and bad cranks. In that time Lycoming has had cam corrosion and follower spalling issues, and bad cranks. Neither manufacturer is perfect. I hear the answer is to keep them plugged in all the time.
 
I question everything but especially this: "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".

Where is the proof? The analysis? True in all climates or just in certain climates? I may not fly at all this year or just a couple of hours because no where to fly to since everything is pretty much shut down but I don't think this is going to affect my engine life here in the ultra low humidity of the Arizona highlands. I especially question the logic of flying around in circles putting extra hours on your engine and consuming all that AVGAS unless you just want to fly around in circles.
You may be right... But I wonder if the higher fatality rate was (and will be after the COVID lockdown nonsense) is non-use of vaporizing skills?
 
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."
An interesting distinction that I hadn't considered. Thanks.
 
When I was flying out of KBFM, (once Brookly AFB) I usually came to work before dawn. The TCM test cell was a stone's throw from our flight line. The sound of a big engine at full tilt was hardly muffled by it being in a building. That roar was there when I left. For 4 days. I am aware that an engine has to be run at one hundred hours at 100% power for certification. Hearing that howl for four days straight gave me new respect for Continental.
 
When I was flying out of KBFM, (once Brookly AFB) I usually came to work before dawn. The TCM test cell was a stone's throw from our flight line. The sound of a big engine at full tilt was hardly muffled by it being in a building. That roar was there when I left. For 4 days. I am aware that an engine has to be run at one hundred hours at 100% power for certification. Hearing that howl for four days straight gave me new respect for Continental.

Four days at full load really isn’t much. I’d bet the engine design that is in your car got a longer durability test at full load than that.
 
You may be right... But I wonder if the higher fatality rate was (and will be after the COVID lockdown nonsense) is non-use of vaporizing skills?
A point to be considered so when I do fly again I will be extra careful. However, flying in circles just to supposedly increase engine life seems a bit illogical since you have to consider those extra wasted hours in the cost benefit (if there is any benefit) analysis. And the most dangerous flying is take off, landing and close to airport traffic. I find it amazing all the the things we are told about GA with no real supporting data.
 
An interesting distinction that I hadn't considered. Thanks.

I have my doubts that having the propeller "driving" the engine causes any significant wear that would cause failure given the limited amount of time an engine is subjected to it. I understand that it would load the bearings differently, but I can't see how it's even worth mentioning.
 
Continental is currently offering a promo of 4 years warranty on new engines. They only way I buy a new TCM engine is with their extended warranty promo like this one. They seems to develope issues with cylinders about 2 years in lately reading the Pireps on BeechTalk.
 
I question everything but especially this: "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".

Where is the proof? The analysis? True in all climates or just in certain climates? I may not fly at all this year or just a couple of hours because no where to fly to since everything is pretty much shut down but I don't think this is going to affect my engine life here in the ultra low humidity of the Arizona highlands. I especially question the logic of flying around in circles putting extra hours on your engine and consuming all that AVGAS unless you just want to fly around in circles.
Because flying anywhere and takeoffs and landings are fun....and good practice. We know Arizona is dry, but surely you see dew in the morning? Flight schools often get 2400 before they need an overhaul. What's the average for GA planes? 20 hours? If they make it to 2000 they're doing well. So a 20% increase above TBO due to routine use is a pretty good data point.

"YOU MUST EXERCISE THE GASKETS"
 
Correlation is not causation so the underlying reason be verified but in any case flying unneeded wasted and dangerous hours to supposedly increase total hours may well create a net economic loss. Also can you document those flight school hours and, if true, it could be that flight schools are simply willing to push their engines further before a major OH.
 
Correlation is not causation so the underlying reason be verified but in any case flying unneeded wasted and dangerous hours to supposedly increase total hours may well create a net economic loss. Also can you document those flight school hours and, if true, it could be that flight schools are simply willing to push their engines further before a major OH.
I think it is probably dependent on other factors as well... But we all know trainers take a beating, in every conceivable way. Engine abuse, airframe abuse, tire abuse....

But they go through, in most cases, 100 hour inspections. For most GA pilots that milestone (100 hours) might not be met biennially... Or even farther apart.

An unused engine is a boat anchor sooner than one used frequently. (IMHO).
 
Correlation is not causation so the underlying reason be verified but in any case flying unneeded wasted and dangerous hours to supposedly increase total hours may well create a net economic loss. Also can you document those flight school hours and, if true, it could be that flight schools are simply willing to push their engines further before a major OH.
All I know is there's a lot of ramp rats that turned into such because the owner didn't have anywhere to go. Then fell behind on maintenance. Then it became too expensive to get caught up. Fly because it's fun. Because it's good practice talking to towers and approaches and take offs/landings. Enjoy a sunset at dusk from the air. I'm not sure how that can be construed as dangerous.
 
Flying is nowhere is not that much fun after 8000 hours but traveling somewhere is usually fun. I bought my first plane ($500, 1946 Aeronca Chief) for weekend trips from college to ranch to save money and ,yes, I did. 22 MPG vs. 16 MPG in my car and 80 octane AVGAS as cheap as MOGAS then since you got an AVGAS tax refund since not using the public roads.
 
Flying is nowhere is not that much fun after 8000 hours but traveling somewhere is usually fun. I bought my first plane ($500, 1946 Aeronca Chief) for weekend trips from college to ranch to save money and ,yes, I did. 22 MPG vs. 16 MPG in my car and 80 octane AVGAS as cheap as MOGAS then since you got an AVGAS tax refund since not using the public roads.
I'd like to get that 8000+hours under my belt before I agree with you.... Please hold.
 
Back
Top