® 2019 Engine Buyer’s Guide In search of the good stuff. BY DAN HORTON 22 KITPLANES February 2019 www.kitplanes.com & www.facebook.com/kitplanes The dirt road leads across the West- Continental, and Superior, which average expected to bring engine assembly skills ern desert to a gate in a chain link about $28,000…not outrageous, but not to the party. Quite a few builders will fence. There are no guards, only a single inexpensive either. All of these engines consider kit availability to be a plus, autonomous drone with a monocle eye. are top shelf boutique products for a very as they prefer to know exactly what is A freight elevator hidden in a lonesome specific application, made in infinitesi- inside their new powerplant. For others, tarpaper shack descends into a cavern so mal numbers when compared to the 97 the learning curve might be a little too secret only a few know of its existence. million cars and trucks produced world- steep, and a ready-to-run package is the Here, hidden in the darkness, is where wide in 2017. A price premium is to be better choice. they keep the good stuff. expected, and those with the means pay One would think the enormous In that room you’ll find the 100-mpg it because they work. Throw in the ubiqui- automotive production numbers could carburetor. Nobody cares about it any- tous 540 six-cylinder, and you’re looking provide a vast variety of inexpensive more, because just a few cabinets to the at the majority of the E/A-B fleet. engines for aviation. Twenty years ago it right you’ll find the 20-pound battery They also get the majority of the sure looked like a trend, but today, the capable of powering a car for a week. The ink, in both magazines and forums, Guide lists only two vendors for a sub- self-cooling beer bottle is in Area C (for so let’s spend a few moments on the $10K water-cooled four-stroke with “Curiosities”), along with the invisible really affordable end of the market, electronic fuel injection and ignition. duct tape. And just down the hall, you’ll engines priced at less than half the aver- Both offer an Asian-based inline three- find the prototype AAE…the Afford- age…$10,000 or less. cylinder four stroke. At this price point, able Airplane Engine. only one offers four-cylinder models The AAE is modular, thus horse- Frugal Flyers with 100 hp or more. power ratings from 50 to 1500 are pos- The Guide lists 34 choices offering 50 hp The key in this segment has been sible by merely adding sections. Being or more at less than $10K. Half are VW development of a reliable propeller speed multi-fueled, it will happily consume based, not a surprise given the mechani- reduction unit (PSRU) as, without it, no-lead gas, Jet-A, or whale oil. Ignition cal layout and the worldwide availabil- the engine rpm necessary for suitable is self-sustaining. All instrument send- ity of aftermarket parts. Despite overall power output results in an unacceptable ers are pre-installed; just plug the sup- similarity, the offerings vary widely in propeller tip speed. Buyers are cautioned plied cord into the EIS of your choice. component quality and design, so buyers to research the reliability of any PSRU Best of all, its Brake Specific Cash Con- are cautioned to do their homework. For application. Good gearing is certainly sumption (BSCC) is claimed to be less example, some choices are delivered with possible (consider the Rolls-Royce than $33 per horsepower per purchase… used, reconditioned stock rods, while Merlin, or the Rotax 912, or dozens of assuming production reaches 100,000 others get new, fully machined forgings. geared radials), but it’s a design chal- units per year. We’ve seen poorly sized cam gears from lenge that has confounded more than It’s not an impossible number. After the bargain basement shelf. There are one manufacturer, and the task becomes all, since WW-II the experts have been several different variations on prop hub more difficult with fewer cylinders. telling us everyone will want an airplane attachment. Support for the hub may be Two-stroke engines have always held in their garage, if they can be built for nonexistent, or a robust bearing. a price advantage. However, here again the price of a good family car. And we Many (but not all) of the budget VW the choices have been shrinking. Rotax, would be building them too, if all those choices are kits, so the builder will be the historical leader in this segment, rich liberal whale lovers hadn’t bought the patent. That’s right…they feared a run on the world’s supply of whales if the AAE came to market, so now it sits, rusting quietly in the dark. Well, OK…it’s a fantasy. There is no cavern. However, there are some afford- able engines, and no cetaceans need be harmed to run them. If we remove a few rare diesels and turbines from the calculation, the aver- age price for all entries listed in the KITPLanes® Engine Buyer’s Guide is a little over $20,000. The highest volume units are the 100-hp 912 from Rotax at around $18,000, and the 160- to 210-hp flat fours fromL ycoming, Lycoming YIO-540 from the Thunderbolt shop. Photos: Dan Horton KITPLANES February 2019 23 today only produces a single aviation the line has begun to blur, particularly Flat Four-Stroke Gas two-stroke. Hirth alone remains as a in the world of diesels. Japan-based design firm AC Corpo- full-line producer of 50+ hp two-strokes The marketplace includes a wide vari- ration continues to offer high-perfor- for sport aviation. There are signs of a ety of interesting small engines. Many mance updates to existing flat-motor resurgent U.S. ultralight market, and if don’t produce enough power to fly a typ- architecture. A monolithic air-cooled true, perhaps we’ll see vendors return- ical E/A-B aircraft. We don’t have space aluminum cylinder with a pressed-in ing to the arena. to list them all anyway, so here we draw liner is the signature product, but AC The bright new spot in the budget an arbitrary line at roughly 50 hp. Some also offers a fresh crankshaft design, segment? It’s now possible to order an listed manufacturers also sell smaller some interesting intake manifolds, and attractive five-cylinder radial for less engines; call or check their websites for a even oil-cooled cylinders. than $10K, built in the Czech Republic complete list, or contact dealers in your AC Corporation split with its previ- by an established manufacturer. They’re part of the world. ous U.S. representative, Advanced Com- light, simple, and sound great! Prices and weights are supplied by the ponent Engineering (ACE), in 2017. vendors. Some prices are MSRP, while Until a new North American distributor The Rules others may be a street price. Quotes to can be found, complete engines will be Before proceeding to the 2019 Engine us in euros or other currencies were con- sold manufacturer direct, with shipment Buyer’s Guide, let us first address the verted to U.S. dollars using exchange rates from an assembly facility in the U.K. rules. The Guide is limited to engines in effect at the time of writing. All prices Even with an overseas shipping cost, available now or in the near future, as are subject to change. As priced, engines the factory-direct pricing is competitive more or less complete units marketed are supplied fully assembled, unless with traditional offerings. Individual to the experimental community. We’ve marked as a “kit.” We’ve tried to deter- components for air-cooled engines are skipped engines marketed as “certified mine exactly what accessories are included available on a limited basis to qualified only,” and those deemed impractical or at a given price and weight, but in the end, engine builders. unavailable. Along the same lines, we what you see in the tables is largely man- BRP Rotax continues as the domi- can’t list every individual engine varia- ufacturer-supplied data. Trust, but verify! nant supplier of piston engines for Light tion a manufacturer may offer. Don’t The Engine Guide is a source of basic Sport and microlight class aircraft. The worry, if you want a particular feature, information. It is not an endorsement. long-awaited 135-hp 915 iS is now in just pick up the phone and ask. Someone Here at KITPLANES®, we have per- production. Rotax reports several have will be happy to supply it. sonal opinions like everyone else, but passed 2000 hours on test stands, and You’ll find engines logically sorted by in the Guide we make no judgments. more than a few airframe manufactur- configuration or family, then listed in You are the aircraft builder, so please, do ers are showing them on their demo alphabetical order. We’ll make no dis- your homework. models. Turbocharged, intercooled, and tinction between traditional “aircraft And now, ladies and gentlemen, in fuel injected, the 915 iS delivers 135 hp engines” and “alternative engines,” as alphabetical order…the Guide. all the way to 15,000 feet. The best selling Rotax continues to be the 100-hp carbureted 912 ULS, by about 2 to 1. The fuel injected 912 iS is in many respects a better engine, but adds about 30 pounds in all-up installed weight due to additional support systems.