f1rocket said:Oh boy, where do I start.
Automobile engines may be of a higher technical level than a Lycoming, but they are NOT superior when it comes to driving an airplane through the sky. Take a look at the main crank bearings and the engine block of a Subaru and compare them to the Lyc. When you are swinging the weight of the prop out front, it requires some hefty support. Lyc's also deliver peak power at low RPM, while the Subies need to scream along at much high RPM to deliver peak horsepower, hence the gear reduction units. I contend that automobile engines are very poor airplane engines because they need to be jerryrigged to make them work.
The benefit they have is that they are cheap because they are mass produced. Can't beat that. They also have great reliability when used for their intended and designed use. Start sticking them in airplanes and you are bringing along a whole additional set of engineering problems to be solved. I don't know any engine engineer that thinks gear reduction units are the best way to turn a prop. No, it's just a band-aide stuck on an engineering problem that otherwise, can't be fixed.
The whole 100LL thing has become the enabling battle cry of the alternate engine groupies. Unfortunately, it doesn't hold water. No one is going to wake up one moring to find that hundreds of thousands of engines that use the product suddenly are silent because no one is making it any longer. I don't doubt that there will be a transition to other fuels in the long run. That's probably why the diesel engine is looking like a viable engine alternative. But you and I will be able to buy 100LL for many, many years to come. Now the price of that gallon of 100LL may be another issue.
Finally, the reason I fly a homebuilt and not a Cessna 150 is because I can upgrade my Lycosaur with electronic ignition, FADEC, etc and get the best of both worlds----newer features and capabilities with proven reliability.
Oops, screwed up the quote in the last post there:
I fly a Sube and rebuilt the engine myself being a racecar engine builder by profession. The engineering, metallurgy, choice of materials, machining and balance of the Sube is far superior to anything seen in a Lyc. I have never heard of a bottom end failure on the EJ series Subes. There is no doubt that they can take much higher continuous stress. This was proven by their wide open run : http://www.subaru-global.com/about/history/1989-001.html#subhead-001
Anyone who thinks that modern auto engines are not capable of spinning at 4500 rpm all day, all month, all year long is simply ill-informed. I built and road raced Japanese engined cars for 13 years making over 5 times their naturally aspirated stock power and running them 2500 rpm over the stock redline. Not one ever suffered a catastophic failure.
What is this? Every Pratt, Wright, Allison, and Merlin had a reduction gear. You call that a band-aid?
My Sube runs on 100LL just fine or 91 octane if I choose.
Proven? Every 24 hours, there are more high speed hours put on cars running in Germany alone, than all the Lycoming engines ever built have accumulated in the last decade. For every hour that Lycs have, cars have accumulated millions of hours. You don't think Lycs break? Better brush up on those accident reports. There are plenty of fatals caused by catastrophic failures and don't forget the class action suits brought against Lyc and their turbocharged 540s where dozens blew up or went only a fraction of the time to TBO. Let's not forget the recent judgement against Lyc for the crank problems and all the other problems these "proven designs" have suffered in the last 5-6 years. This is a joke when you are paying $30,00+.
Some might find this interesting: http://www.sdsefi.com/air7.html