I’m building an experimental airplane and went through the same thought processes, Ed. I really liked the idea of the Sube at first; the more I read though…there are LOTS of failures of the subes, just read about one TODAY on the air-soob forum, the pilot walked away fortunately. Between the PSRU issues and the injection failure modes that seem to be a constant problem, I eventually bought a continental 0-470. You can buy a mid-time lycoming or continental for a LOT less than $25K these days, in a recent airplane magazine i saw that continental is running a special on factory rebuilt engines for 17K.
8-10K will buy you a mid time REAL airplane engine where you don’t need a psru, that will be worth some wonderful peace of mind at 6000 ft AGL.
Best wishes, Ed, maybe I’ll see you at OSHKOSH in a year or two…work on it everyday, even if it is for 2-3 minutes, make it a rule! jaysmiths@yahoo.com
hello ed i being a mechanic for many years and pilot as well have what would be a good solution for you . you can use the subaroo engine it just great (but)you must have it rebuilt for the extra thrust bearing that it going to need for the prop thats going to fit it and youll have to go to a airplane mechanic shop and ask what kits they have for that know . because its not like just driveing a car in the air.that prop is going to put alot of stress on the engines bearings, and regular bearings wont work there not strong enough the thrust and vibration will pull the enging apart ,and you really dont wont that during flight… youll need all the extra reliable electronics associated with engine spark ass well. have fun and dont be affraid to ask the air mechanics for help they love to help…
have fun. and good flying…
Get the aircraft engine. If a Subaru engine quits on the ground then you can coast to a stop. If a Subaru engine quits in the air your family will be planning your funeral. The Subaru engine is in no way as reliable as an aircraft engine. It was not designed or built to power an aircraft.
All horizontally opposed carbureted aircraft engines are equipped with a de-ice mechanism which heats the area of the intake upon pulling a knob. It isn’t necessary to pull over and wait for the ice to melt. Fuel injected engines need no such device as they do not have a carburetor venturi. Carb ice is not an issue for either type of engine.
“I remember back in the early days of the VW Beetle, Popular Mechanics (or was it Mechanix Illustrated?) ran an article on a homebuilt using a VW engine.”
“If a Subaru engine quits in the air your family will be planning your funeral”.
After seeing Captain Sullenberger put an Airbus into the Hudson River, surely you realize that planes without power are capable of gliding. The lighter the plane, the farther it will glide. At an altitude of 10,000’ above the ground a light plane pilot has an option of landing somewhere in 100 square miles. I’ve practiced the maneuver many times. Most of the time it is necessary to “waste” altitude to get down to the best flat spot possible. I even know a pair of pilots who landed a fuelless Cessna Citation jet on an interstate highway without damage. While flying may be slightly dangerous, it is not inherently deadly.
I looked at the Subaru conversion also but opted for a non-certified version of the 0-320 supplied in kit form and assembled by an authorived shop for about $21,000. The Subaru is about 80 lbs heavier which could be a factor. I will be installing an engine cowl with the round inlets, diffusers and plenum to minimize cooling drag. I’m not sure how that would compare to the Subaru version although pictures I’ve seen on the website show normal inlet and exit areas as far as I can tell. Good luck with your project!
You’ve Carefully Selected A Couple Of The Successful Emergency Landings.
They don’t all turn out that way. I’ll bet someone could find some examples.
I will tell you that either of those could have ended in tragedy, quite easily.
I agree. Planes can glide to varying degrees, but losing power, especially at critcal points during take-off can make one home sick in a hurry ! That’s why aircraft are designed with several redundant safety features.
As with cars, aircraft incidents are monitored to see if a particular defect or problem creates a pattern triggering recalls or airworthiness bulletins for certain nearly identical factory manufactured airframes or engines.
When people try building their own planes or cars in their garages or living rooms it makes this nearly impossible. Every type problem imaginable can surface and they do.
Since the earliest days of aviation, automobile engines have been used in homebuilt aircraft. By far, the biggest reasons have been those Ed is concerned with, mostly being price. However, as noted by the hosts, the “tried and true” engines are antiquated by comparison with current automobile engine technology. And in addition to the initial buy-in of the certified engine, the costs to maintain and eventually overhaul is astronomical as compared to auto conversions.
But before Ed decides based only on these factors (cost and technology) he has to ask himself if he’s mechanically inclined enough to deviate from the plans far enough to (in essence) engineer the installation, setup (including troubleshooting) and maintenance of this unique installation.
From what I heard, and from the fact that he chose to ask “car experts” about aircraft engines rather than those who have successfully installed auto engines in airworthy aircraft, I’m thinking that Ed needs a lot more education before he can make that call.
With that, I would encourage Ed to make plans to visit a “fly-in” event that’s coming up at the end of March, where he’ll get to see (and potentially fly) several experimental aircraft with automobile engines installed and get to talk to the builders and pilots of these aircraft.
The event is called the Alternative Engine Round-Up, and will be held on March 27th at the airport in Jean Nevada, just a few miles south of Las Vegas.
In addition to this, there is a collection of books published by CONTACT! Magazine called “Alternative Engines” of which there are three volumes covering 15 years of automobile engine conversions. These books are rich with information, a lot of which features the Subaru. http://www.contactmagazine.com/Vol3tableofcontents.html
Some tips for Ed. There are thousands of people killed in auto accidents, too (in fact, the death rate for motorcycle users is higher than for homebuilt aircraft, according to the NTSB), so those focusing on John Denver and John Walton accidents are working w/ bad info and their own biases. Get some good advice: Joining EAA is essential to use their tech counselor and flight advisor programs. I’d highly recommend a good community publications such as CONTACT! magazine that specializes in auto-conversion systems for aircraft. And decide whether the extra work to make the auto conversion vs. buying a well-maintained used aircraft engine is your better choice. Good luck!
Excellent information. The fact that Ed apparently hasn’t pursued all those available sources of advice for his project makes me glad I don’t live under his flight path! Both building and flying a plane requires a very high level of skill and attention to detail. Like you said, Ed needs a lot more education, not a good sign.
I really wasn’t trying to be rude. And clearly I’m not the only one on this thread who votes for the certified engine.
Production aircraft (Piper, Cirrus, Cessna, etc) get their engines from mfrs other than Subaru for a reason.
Click & Click mentioned that the O.C. was trying to save money, so I used the Alaska Airlines example to illustrate what can happen in aviation when people and organizations try to save money by taking short-cuts.
Sorry if you thought my comments were “snarky” but sometimes you just have to call it the way you see it.
I wanted to just throw in that in the aviation biz, $10k isn’t really a lot of money. Again, it will be money well spent for a nice aircraft engine that will be more reliable and efficient.
For the record, I really am sorry if I was rude to Ed in my original post, but I feel strongly about car parts going in airplanes. CSA myself and others pointed out what can happen to people & their machines (bad things happen to good people) in cases like this.
Even though the human element is the main killer in aviation, you certainly don’t want the chips stacked against you when you’re 300’ above a residential area on a hot summers day (where I fly there’s a neighborhood right off the end of the rwy, just beyond the airport perimeter fence).
Ed, good luck with your project, have fun and please put a good engine in there.
Hi Folks,
Heard the show (try not to miss one) this week. I want to pass on a contact that might be of great help to Ed. My long time friend, Mike Arnold, designed and built a plane that still holds (I think) the world’s record of speed for this type of plane. He will be a good one to talk with. Here is his website. Look it over and go from there. His contact info is on the site:
http://www.ar-5.com (don’t know how to make this a live link on this page, so just copy & paste. Good luck. And for goodness sake, don’t put the car engine in your plane.
Every aircraft engine will eventually need an overhaul. Ed should talk to A&P mechanic about how much cost and how often these engines need an overhaul. The subaru engine is modified. What are the modifications? Propeller shaft rpm’s determine what type of propeller Ed can use. If Ed’s plane is designed to accomodate either engine, are the weights and cooling system the same. Ed can talk to the Subaru engine modifier about a list of satified customers. Fuel injection, computer controlled ignition, and turbocharging are exciting incentives. If it was me, I would pay an A&P mechanic to do some research. How much fuel will be used? What is the most reliable engine? How much would each cost to repair?
I don’t see much of a problem with Ed using a [properly converted] Subaru engine in his plane. I once saw this exact conversion at the Oshkosh EAA fly-in several years ago, and talked to the owner. It was a very neat, well-thought-out installation, and included a radiator mount below the powerplant. I have a local acquaintence (Downers Grove, IL), who is building a plane with a 3-rotor Mazda rotary engine in it. By the way, most light planes can glide pretty far even if the engine does fail!
That is a provocative way to make your opinion known. I urge you research experimental aviation in the US. I think your opinion is based on ignorance, I do not mean this in a hostile way. If you look into it I think you will realize that experimental does not mean fake or dangerous. John Denver made a mistake that was aggravated by the location of a fuel valve he was trying to turn. If he had been killed on a motorcycle would you say he could have afforded a real car?
Building an airplane (and subsequently flying it) does not make you crazy. Homebuilders frequently build planes to as high a standard, if not higher, than the factory-built ones.
Tom and Ray are somewhat, shall we say, provincial on their opinions in this respect. They know a lot about cars but admittedly nothing about airplanes.
I would stick to an aircraft-specific engine. For an RV homebuilt that could be a clone of a Lycoming 0-320 or a mid-time or rebuilt certificated engine. Old tech they may be, but the Lycoming and Continental engines have been optimized for their job and are very reliable and efficient, if operated properly. The Subaru conversions sound good, but as others have pointed out, they were never designed to operate at 75% power for hours at a time.
Also, bear in mind that a gear reduction automatically costs you 10% loss in mechanical efficiency, as well as giving you something else to break. If the auto conversion weighs 80lbs more, that is huge in a 1,200-1500 lb aircraft.
Judging from the EAA’s Sport Flying magazine (and my trips to Oshkosh), enthusiasm for auto-conversion engines in homebuilts has declined since I joined in the early 1990’s. There is probably a good reason for that.
“Judging from the EAA’s Sport Flying magazine (and my trips to Oshkosh), enthusiasm for auto-conversion engines in homebuilts has declined since I joined in the early 1990’s. There is probably a good reason for that.”
Admittedly, the EAA is making an effort to resume proper coverage of true grass-roots aviation, which includes alternative engines. The newly revamped Sport Aviation, the EAA’s flagship publication and the eNewsletter, Experimenter, bear this out. http://www.eaa.org/experimenter/
Although it may appear that auto engine conversions have waned in the past few decades, the truth is, more auto engine conversion choices are available to the builder today than at any other time in experimental aviation history.
