I'd rather have an LS than any aircraft engine. It sucks that they really stopped major development 50 years ago. A water cooled, injected engine would out perform almost any aircraft engine.
Honestly one of the reasons I don't own a plane is that everything in GA is basically from the 50's unless you are buying new. And then the engine is still from the 50's.
In reply to Teh E36 M3 :
We prefer reliability over innovation. Those old engines get you home. Think of how many bad engines we experience as enthusiasts. Now imagine Subaru ring land or Porsche IMS failures...at 10,000ft.
BTW, aero engine innovation didn't stop in the 50s, just by Continental and Lycoming. I see plenty of innovation every year at Oshkosh. You'd be astounded.
Appleseed said:In reply to Teh E36 M3 :
We prefer reliability over innovation. Those old engines get you home. Think of how many bad engines we experience as enthusiasts. Now imagine Subaru ring land or Porsche IMS failures...at 10,000ft.
BTW, aero engine innovation didn't stop in the 50s, just by Continental and Lycoming. I see plenty of innovation every year at Oshkosh. You'd be astounded.
I'm a pilot... prefer turbine to anything but I'd still take an LS than any LY-Con air cooled antique. I understand there is innovation, but there is only so much that can be done with that tech.
The thing to remember with the Lycoming style engine vs something like an LS is there is a LOT less to potentially fail. The Lycoming just needs a fuel supply, that it! It will run without an electrical system (uses magnetos) or a radiator or water pump (obviously). There isn't even a fan (like a car air cooled car motor)! The engine is direct drive, so no reduction drive to fail, and it will turn at about half the RPM of an LS, so less general wear. It also has an almost completely redundant ignitions system (two magnetos, two spark plugs per cylinder). They are, in general, insanely reliable (e.g. most engine "failures" are the result of running out of fuel)
Yes, the LS is a very reliable engine, but it will have a lot of electrical components attached to it. Certainly you can likely build up an LS to, maybe close, level of reliability, but it will be costly. The last I read about the LS conversions is they got them reasonably good, but the cost of the conversion was basically the same as a similar Lycoming! (you need to get it certified) and I suspect they still fall very short in pure reliability.
I guess, given all that, would you rather be in a Lycoming powered single engined plane crossing the northern Atlantic (as someone here's plane did at one point) or one with an LS?
aircooled said:I guess, given all that, would you rather be in a Lycoming powered single engined plane crossing the northern Atlantic (as someone here's plane did at one point) or one with an LS?
Not sure since I'll never fly a kit plane across the atlantic, but for flying within 2 hours of Richmond, VA, and divert airports every 5 miles or so, I'd rather have the cool factor and sound of an LS in my RV8/T51/etc. kit plane.
R985s came out before the second world war. They're still reliably powering aircraft today.
In reply to aircooled :
Yes. There are a lot fewer single points of failure, but a much much worse MTBF on each of them.
I would rather fly behind any uncertified engine released after OBD2 than behind any certified piston engine.
In reply to chaparral :
I am curious what you base that on. The O-360 Lycoming (that is a carbed engine btw) has a TBO (time between overhaul) of 2000 hours. Perhaps you are confusing that with MTBF? They are very, very different. Depending on how you calculate that, that's sort of equivalent to 100,000 miles for a car, which doesn't sound great, but....
- That's 2000 hours at mostly 75% power, with a decent amount of time (maybe 10-15%?) at 100%. Street car engine get nowhere near that 90% of the time, and it is closer to an endurance racing engine... in a 100,000 mile race (obviously not quite as strained as a race engine).
- The TBO is recommended, not required. My brother in law had a Cessna 172 that was over 2500 hours and was ready for a rebuild, but still ran very good. The idea is to rebuild them to keep them at 100% (ish), not when they drop a valve or destroy its rings, which more how cars engines are dealt with.
- The need for a rebuild is because of almost any reduction in output, in airplanes, especially small ones, is rather significant. They need all the power they can get. Also, avoiding almost any possible actual failure is the goal. Breaking something like a rocker arm on a car, or loosing 25% of power because of worn rings isn't as big of a concern. It's a huge concern in a plane.
I completely get it if you want to criticize classic Lycoming style engines as inefficient, which they are, especially in comparison to modern car engines, but I really don't see reliability as one of their downsides. They are also, insanely expensive, but at is mostly because of certification and insurance concerns.
In reply to Flynlow :
I get it, but the FAA very much does not agree with you. Having planes with the plan of "hoping" they can make it to an airport is not a thing they want. Some of those planes can easily end up in someone's living room in Richmond (i.e. in a built up area where there are almost no good option to put down on)
Curtis73 (Forum Supporter) said:mfennell said:APEowner said:wae said:I find it bizarre that I'm the guy to say this, but wouldn't it be a really good idea to not add to the number of engines that are sending lead particles out their tailpipes?
Yeah, I don't feel good about that. In fact the whole racing thing is ecological disaster. Driving a truck and trailer hundreds of miles to drive an old car around a closed circuit for hours before driving the truck and trailer back the same distance. I try and mitigate that by being responsible in other aspects of my life but still.
FWIW, leaded race gas is worse than Avgas. 100LL is about 2 grams/gal of TEL. Sunoco 110 is about 4.
I believe the new Avgas spec is 0.56 grams/gal. I think that started in 1998. I remember pilots complaining about their old Lycomings not being able to run with that low lead content without re-doing the valves and seats.
It's 0.56g/liter. 2.12g/gal according to the infallible Internet.
I've seen a number of O-360s with 3000hr+ SMOH with compressions still in the 70s.
Would anybody really wanna be over the Appalachians in an airplane powered by a 5.2L Voodoo, LT1, Subaru EJ/FA, etc etc? That's a no from me, dawg.
With a homebuilt, there's no reason that a Lycosaurus needs to be completely ancient. It's trivial to build one with electronic ignition and fuel injection using ECUs adapted from the automotive world. This is my plan--you still get a reliable engine designed and built with aircraft use in mind, but modern engine tech. You make it reliable with dual ECUs and dual alternators. This makes far more sense than putting an LS in an airplane.
In reply to Berck :
Now that's what I'm talking about.
In reply to aircooled :
This is kind of why there is/was a bunch of people putting rotaries in airplanes. They prefer to be run at 70-100%, they are reliable, and the neat thing is, if you lose all your coolant for whatever reason, they won't seize when they get extremely hot. The iron rotors won't expand so much that they seize in the engine, unlike an aluminum piston. They will run at least long enough for you to find a safe place to put down. Might not ever start again without an overhaul, but that's a secondary goal at this point.
Teh E36 M3 said:I'd rather have an LS than any aircraft engine. It sucks that they really stopped major development 50 years ago. A water cooled, injected engine would out perform almost any aircraft engine.
From what I've read, the LS doesn't have the success rate you'd expect. Several people have died when the ECU went into limp mode, for example. As someone else pointed out, there are a lot of things that can go wrong and you'd hate to be the person who discovered a new failure mode.
Berck said:The trend now, of course, is to put Rotax snow mobile engines in light aircraft, which requires a gearbox.
Rotax has a whole line of aircraft engines, from 80-160hp. At least some of them have 2000hr TBOs. Liquid cooling, dry sump, electronic ignition, fuel injection (in most). They do all have a gearbox. https://www.flyrotax.com/p/products/engines
Rotax aero engines have been around for a long, long time. The ultralight community owes much of its existence to them.
Teh E36 M3 said:I'd rather have an LS than any aircraft engine. It sucks that they really stopped major development 50 years ago. A water cooled, injected engine would out perform almost any aircraft engine.
People have swapped LSes into airplanes, it doesn't work as well as one would think.
Water cooling adds weight. LS motors need more revs to make power, which means you need a gearbox, which means even more weight. By the time you've done the conversion the plane is a couple hundred pounds heavier than it was before, and it only had about 300-400 pounds of payload (which includes pilot & passengers) capacity before, so you've cut that in half. Sure it has a lot more power, but you've lost a lot of the utility.
Piston powered GA airplanes use big, low-revving, air-cooled engines for a reason, and it's not only because of the FAA being conservative (although that is definitely part of it).
In reply to mfennell :
Yeah, I've flown a CTLS with the Rotax. Really not an engine for airplanes. Water cooled heads, air cooled cylinders. Screams at 3600rpm at redline, sounds like it's going to blow up and is anything but confidence inspiring. Takes forever to get hot enough for takeoff. On a cold day, it's pretty much impossible to keep enough power in for it to not complain about being too cold on descent. I'd prefer the comperable Continental IO-240 any day.
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