Is an Automobile Engine Conversion for You?
By Patrick Panzera, EAA 555743, firstname.lastname@example.org
Since the earliest days of aviation, automobile engines have been used in homebuilt aircraft. By far, the biggest reason has been cost. However, some will say that technology is the key reason for using an automobile engine, pointing out that the “expensive” certified engines are antiquated when compared with current automobile engine technology. A perfect example of this would be the Wankel, overhead cams, combustion chamber design, water cooling, and the use of electronic fuel injection or electronic ignitions. But no matter who you talk to, all will agree that in addition to the initial buy-in of a new certified engine being substantially higher than an auto conversion, the costs to maintain and eventually overhaul that certified engine is astronomical as compared to auto conversions. Is an auto engine for you?
Before deciding based only on these factors (cost and technology), we must ask ourselves if we are mechanically inclined enough to deviate from the plans far enough to (in essence) engineer the installation, setup (including troubleshooting), and maintenance of this potentially unique installation. It’s a pretty huge undertaking.
If the answer is yes (and I hope it is), I would still recommend finding other like-minded individuals to confer with, hopefully those who have either already been successful with the same engine/airframe combination you’re contemplating or at least are familiar with the firewall-forward (or -aft as the case might be) installation of the engine you’re considering. There really is no good reason to reinvent the wheel. If the engine has never been used in an aircraft before, that might be a clue that maybe it’s not the best idea after all, but not always. Someone has to be the first; are you that person?
Many might say that it would be best to ask an A&P his or her opinion of installing that engine in your plane. Unless you know the person to be a strong advocate of auto conversions, or potentially knowledgeable with the proposed airframe/powerplant combination, asking for an opinion would be as pointless as asking a goldfish the same question, except the goldfish probably won’t insult you with an answer. It’s my experience that most A&Ps are: 1) not interested in homebuilt aircraft and 2) absolutely not interested in auto conversions even if they are interested in experimentals. There are always exceptions to this rule, and those are the people to seek out. One of two personal favorite examples of this is when I asked the A&P at my local fixed-base operation, the man responsible for keeping airworthy the plane I learned to fly in (so I totally respected his opinion), what he thought of the Corvair engine. His reply: “It’s a great engine...in the car.” Not long after that, I was at an EAA lunch barbeque, and a crusty ol’ A&P was holding court with a bunch of aviators eager to learn from his decades of experience. With all authority he proclaimed that no wooden propeller can survive over 2,450 rpm. So just because they have the paperwork necessary to wrench on planes for a living, it doesn’t automatically make them experts when it comes to installing automobile engines in experimental aircraft.
So if the local A&P is not the person from whom to seek advice, who should you talk to? As I said before, seek out those who are doing it successfully. Is there someone in your chapter that’s “been there, done that” successfully?
The fly-in season has begun. Virtually every event on the horizon will have its share of auto conversions in attendance. One particular event is the Alternative Engine Round-Up. For the past six years (this year will be the seventh), experimental aviators from all walks of the homebuilding community have converged on the southern tip of Nevada to spend the weekend with other automobile and alternative engine enthusiasts. Although the event started at Laughlin/Bullhead, it has now made a home in Jean, just south of Las Vegas.
In addition to this, there’s 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 and are a great place to start your education. http://www.contactmagazine.com/altengines.html
In addition to Jean, this year I plan to attend Sun ’n Fun at Lakeland, Florida, ,Golden West; Arlington; EAA AirVenture Oshkosh; Flabob (EAA Chapter 1 Open House); COPPERSTATE; and perhaps a few small events related to soaring and type gatherings. I hope to see some of you at these events, all of which will be great for learning about automobile conversions; feel free to look me up.