Of the four major forces of flight, none keeps the typical homebuilder awake at night more than thrust. After all, gravity is God-given and drag appears automatically. Lift must be generated by building wings, but thrust comes only after a seemingly endless circle of engineering compromises and intertwined consequences. It can cost a ton of money, and the choices made in those sleepless hours have performance and financial consequences that last the life of the airplane.
In short, no other single component of the building experience costs so much or has such a profound effect on the airplane’s personality and performance as its engine. And beyond the science of converting 100LL into a lot of noise and some thrust, there are the man-made considerations such as warranties and resale values and perhaps the psychological tug of a “free” core engine hiding in the back of some hangar.
In this buyer’s guide, we’re skipping over the engineering of deciding which engine is best for your airframe and flying direct to the commercial realities of what engines are available. In some ways it’s a wide field, with certified airplane engines at one end and auto conversions at another. This month we’re examining the traditional aircraft-engine market, the familiar Continentals and Lycomings, along with their aftermarket clones, plus engines that are becoming increasingly popular in the Light Sport Aircraft realm, and the vestigial radial offerings. Next month, we’ll present the alternative auto-engine conversions and cottage-industry specialty designs for those with a tinkerer’s heart.
State of the Market
Viewed from afar, the traditional airplane piston-engine business is a lonely hamlet hanging on to the old ways at the edge of the woods. For mainstream kit builders, there are but two manufacturers that have dominated, Continental and Lycoming, and their expected bread and butter—new engine sales to big airframe manufacturers such as Cessna and Piper—trickle along, but don’t have the flow to drive major innovations such as all-new engines. Compared to the frantic rush in the electronic, automotive and medical industries, the pace of progress in piston engines is glacial, chained by an unresponsive regulatory climate and market demand stymied by a shrinking pilot population and an uncertain world economy.
Now that we’ve cheered you up, let’s just say that we don’t want to blow a lot of smoke about exciting breakthroughs just around the corner. Yes, government drone development may spiral down to general aviation eventually, and a healthy number of evolutionary improvements are coming to market, but nothing revolutionary is popping out of the clouds. In a way this is comforting, for unlike avionics purchases, your 200-horsepower, four-cylinder powerplant won’t be going out of date anytime soon. Even considering the 100LL fuel availability question, there’s no reason an engine bought in 2013 shouldn’t be swinging a propeller long into the future.
If there’s any upside to the brutal market, it’s been cleansing in the same gentle way a warehouse fire clears out old inventory. Most of the marginal shops—and unfortunately some of the good ones, such as Mattituck—have closed since the economy faltered. What’s left in the Experimental Continental and Lycoming engine business are mainly the more-established, better-equipped shops with a history of both performance engines and a good base of certified overhauls.
And let’s not forget that while Continentals and Lycomings may be traditional, they are intelligently designed, highly developed and robustly rebuildable. It’s essentially impossible to beat these engines in the 200- to 350-hp range. For less than that, Rotax rules in Light Sport Aircraft, and UL Power is making a strong bid.
Continental O-200
The Experimental side of Continental engines is simple: There aren’t any, save for the O-200 Lightweight Aviation Engine. Otherwise, the company sells only certified engines and service parts.
This helps explain why Lycoming seems to romp freely across the Experimental landscape, but it has not kept many Continentals from achieving popularity in the homebuilding community. The big-bore IO-550 series, for example, is a major player in the go-fast composite crowd, often in stock, certified form, or as a custom build from an engine shop.
Continental’s mid-size mover is the intriguing IO-360. It’s smooth, powerful and boasts angled valves and tuned induction, but as a six-cylinder, it is heavier and more expensive than comparably sized four-cylinder Lycomings. It seems a natural starting point for a bold hot rodder to play with.
At the small end of the spectrum, the evergreen O-200 has taken another lease on life in Experimental trim for LSA use. Continental has trimmed fins and flanges to reduce its weight, but it’s still about 75 pounds heavier than the Rotax 912, so it competes as it can on price and “Made in the USA” heritage. It should prove indestructible at 75 hp and 2500 rpm, too.
Kit, Complete, Overhauled or Certified
Traditional Continental and Lycoming aircraft engines can be broadly categorized as either certified or Experimental units. The certified engines (and propeller combinations) are exactly what they sound like: FAA-recognized engine and prop combinations fitted to certified airplanes. When transferred to Experimental aircraft, certified engine and prop combinations have the advantage of, well, not being so experimental. Unfavorable harmonic speed ranges and other lurking demons uncovered only by thorough engineering are known and addressed with certified powerplants, meaning you don’t have to play test pilot quite as convincingly. The FAA recognizes this advantage by requiring a shorter flight-test phase for certified installations, typically 25 hours instead of 40 hours for Experimental engines. Later on, you’ll find a certified combination is a good thing at resale time.
Not surprisingly, buying a new certified engine and prop combination is a bracing splash of financial ice water, and is not the most commonly exercised option. Sourcing a timed-out certified combination in the classified ads is perhaps more common, though good core engines are not as plentiful as they once were. But if you have a good core, it can be rebuilt to certified standards to preserve its certified status; modify it, and it becomes just another Experimental engine.
For those building a well-proven design—an RV comes immediately to mind—there is little experimental in the finished airplane when fitting a certified engine and prop combination. Such planes cost more initially but shouldn’t require anything more than regular maintenance, and they boast good resale value because in many people’s minds they are technically equivalent to the most proven certified airplanes. Van’s reports that most of its customers purchase new engines through Van’s, while some international customers are forced to purchase new certified engines due to regulations in their home countries.
Lycoming’s Thunderbolt line begins with the 233, seen here in 120-hp, AEIO-233-EXP trim on an FK12 Comet biplane. At the other end, Thunderbolts range up to 400-hp, eight-cylinder IO-720s.
Lycoming’s Experimental offerings are offshoots of its certified engines and are offered via two avenues: the OEM Experimentals mentioned earlier and the Thunderbolt series. Like Lycoming’s certified engines, the Thunderbolt line ranges from the LSA-targeted O-235 on up to the IO-720 eight-cylinder monster.
Thunderbolt engines are built in their own section of Lycoming’s factory by two-man teams using regular Lycoming parts, but to tighter balancing tolerances, using ported and polished cylinders and with custom choices in color, chrome and configuration. The latter is one of the Thunderbolt’s main advantages: Lycoming has a huge inventory of sump, intake and accessory locations available, accommodating almost any need. Slick magnetos, harness and spark plugs, Volare carburetors, mechanical fuel pumps, Airflow Performance or Precision Airmotive fuel injection, plus spin-on oil filters are Thunderbolt standards.
Thunderbolt engines are available in Signature, Extreme and Competition trim. The Signature is the bread-and-butter, standard-performance Thunderbolt and carries a two-year, 200-hour warranty; the Extreme engines employ power boosters such as higher compression or boost and have a one-year, 100-hour warranty. The Competition engines are all-out and un-warrantied.
Because they are so popular in both the certified and Experimental worlds and provide the basis for the entire clone-engine movement, we’ll note Lycoming’s O-320 and O-360 four-cylinders share the same crankcase and 5.125-inch bore. The difference is the stroke, which is 3.875 inches on the 320 and 4.375 inches on the 360. Both engines are available in a large number of carbureted, fuel-injected, aerobatic and sump/fuel servo configurations. The 360 cylinder is also used on the six-cylinder 540, making it the most widely used cylinder in the Experimental engine world.
Something to remember when going the certified route is that aside from oil and spark-plug changes, a kit builder with repairman’s privileges can’t legally maintain such an engine. And, as just noted, any modifications at any time, even long after the airplane is flying, must have an STC—or the engine changes to an Experimental.
Builders interested in the 225- to 400-hp range gravitate toward six-cylinder Continentals and Lycomings. Almost to a one, these engines are built by private engine-overhaul shops, such as this IO-540-EXP Lycoming from Barrett Precision Engines.
Not certified, but certainly familiar, are aftermarket versions of the 320 and 360 Lycomings. Such EXP “clone” engines can actually come from Lycoming in the case of its Thunderbolt line, or just as easily from ECi (Engine Components International) or Superior. Sometimes these clones differ from certified engines only in their paperwork because the component parts are all certified.
Furthermore, these clone engines are also typically sold disassembled as kits. The idea is that everything required to assemble a new engine is delivered at one time, saving the hassle of separately sourcing every bolt and washer, then verifying each part, rebuilding what’s usable and replacing what isn’t. Such kits may seem expensive at first, but they can be a huge timesaver.
ECi uses the Titan brand name, most famously for its cylinders, but also for its Experimental engines such as this IOX-360 Titan EXP.
Lately, the major initiatives at San Antonio, Texas-based ECi have been extensive testing and updating of its cylinders, a new 409 stroker engine and a goal of assembling and dyno testing as many of its kit engines as possible in-house.
ECi’s engines start with clones of Lycoming’s 320 and 360, then add a stroker version of the 320 measuring 340 cubic inches, a 360 with 0.125-inch extra stroke measuring 370 cubic inches, and the latest 360 stroker measuring 409 cubic inches. The 340 is very popular with builders of Carbon Cub-type aircraft, and the 370 is a hit with traditional 360 applications.
The 409 is rated at a muscular 230 hp while weighing about the same as a 360. It boasts a sporty 10.5:1 compression ratio and should prove irresistible to hot rodders.
ECi is proud of its newly upgraded cylinders. These were born from adversity, after a rash of failures in ECi’s previous jugs. The company built a cylinder-fatigue testing rig, made the necessary corrections and reports that its Titan brand cylinders now outlast any competitor’s. ECi is also back in the O-200 Continental cylinder business, but doesn’t have a complete O-200 engine. ECi also confirms that it’s done some development of a 540 clone, but won’t comment further. Our bet is there isn’t enough demand to justify the expensive new six-cylinder engine case.
In fact, the time and hassle savings are so great that in a few instances where all of the clone parts are certified, shops can “rebuild” an original certified Lycoming by removing its data plate and attaching it to a new clone engine. It’s no different than if the parts had been sourced separately, and everyone saves a bunch of time. It’s certainly a quick way to return to new tolerances and upgrade to roller lifters.
Experimental engine shops say approximately 80% of their business is for 360 Lycomings, and, naturally, most of those are going into RVs. This Aero Sport Power IO-360-M2S, destined for John Tierney’s RV-7A, is about as typical as they come.
Getting back to the disassembled kits, we’ll note the number of engine kits screwed together in homebuilders’ garages is tiny. More typically, builders order the kit engines through an engine shop, which then does the assembly. That’s probably a smart idea for all but the most experienced amateur builders.
Yet another option, just developing at our press time, was a kit engine-build school Superior is considering. Like builder-assistance workshops from airframe builders, the assisted engine assembly would join your labor and the engine manufacturer’s knowledge and facilities in a compelling combination of education, lower cost and time savings.
The “Great Recession” was hard on Superior, which reemerged under Chinese ownership. This has given the company a newfound stability, resulting in a touch of profitability and growth in late 2012. Company insiders say the Chinese are mainly interested in their long-term ability to supply their home market and leave the U.S. branch’s activities in North America up to the folks in Coppell, Texas.
And they’ve been busy in Texas with continued production of the XP-320 and XP-360 engines, along with a resurrected angle-valve 400, the elimination of the much-advertised but never delivered 408 and a new low-octane fuel initiative.
Like Lycoming, Superior offers its garden-variety 320 and 360 engines in complete, OEM-certified and Experimental guises, with the Experimentals available as complete engines or as kits. Superior makes all of its own parts from the case up, and all parts enjoy dual citizenship as both PMA-approved Lycoming replacement pieces and Superior Experimental parts.
Superior reports the 180-hp 360 is easily its bestseller, and they cover the market with 184 models of this engine when all mounting, accessories and compression ratios are accounted for.
Although the company’s web site is out of date, speaking directly to Superior confirmed that the 408 engine is a dead issue. Engineering resources are instead going into the interesting XP-400, an engine Superior sold a handful of in 2008 before its change in ownership. It’s based on the traditional 360 architecture and uses roller lifters, a front governor pad and 8.5:1 compression to allow use of either 100LL or mogas. Notable are angle-valve cylinders for good power—it’s rated at 215 hp—and a shallow, forward-facing, cold-air Silverhawk fuel-injection induction that eliminates the need for a deep cowling. There is no carbureted version.
Also in development is a low-octane 360 using a larger bore. The idea is to supply backcountry pilots, missionaries and anyone else faced with sketchy fuel supplies. At deadline, a single test engine had run well on 100LL and was awaiting dyno time with lower octane fuels, so don’t expect it to go on sale soon.
Curiously, over the last year or so Lycoming may have priced itself out of the kit engine business. Shop owners report they can rebuild a core engine, build an engine from their existing core stockpile, or use an ECi or Superior kit for considerably less than going with a Lycoming kit. Lycoming’s Thunderbolt engine line remains competitive, so perhaps the company just wants control over assembling the engines.
Once past the certified and clone engines, there is the option of custom building an Experimental engine using any combination of OEM and aftermarket parts. This is a popular path for those wanting something special, such as racers, aerobatic competitors and the power-jaded, as well as those whose engine shop can put together a nice powerplant from their parts pile for a competitive price. This is also popular with parts scroungers and traders who have accumulated a pile of core engines or components; they can trade in parts to an engine shop, along with some money, and come out with a traditionally based Experimental engine for relatively little cash.
No matter where you purchase your engine, breaking it in on a dyno is money well spent.
Ly-Con says most of its Experimental customers these days choose to buy a core engine from Ly-Con rather supply their own. It’s simple economics: The Ly-Con core has a known, set price (around $5,000-$6,000). But when the customer supplies the core, there are often expensive surprises inside, and in any event, insisting on rebuilding the exact engine you walked in with will almost always slow down the process, even if there is nothing other than normal wear.
Playing the 900-pound gorilla in the Light Sport market is Rotax, with a dominating lineup that grew to three engines in 2012. Much is right with the Rotax combination, including a demonstrated ability to deliver on promised future product, good capitalization, technical sophistication and worldwide distribution, but the overwhelming advantage the Austrian engines have enjoyed is a lopsided power-to-weight advantage over the competition. In the weight-crazed Light Sport Aircraft world, this is vital and has put Rotax at the top of the heap despite moderately high pricing.
The big news from Rotax in 2012 was the debut of the 912 iS fuel-injected engine. Whether the sophisticated, electronically controlled engine’s easier starting and fuel consumption advantages (it will burn noticeably less 100LL, 91-octane and E10 mogas, in any combination) outweigh its higher price, bulkier packaging, weight gain and unchanged (or slightly lower) power output is the current debate. It seems scratch-built or new design airframes are needed to logically fit the new engine—Van’s says it would take a full redesign to fit it to the RV-12—so as long as the carbureted 912 ULS is available, we expect it to be Rotax’s most relevant engine in North America. One real-world bellwether to monitor is the 912 iS-powered Flight Design CTLSi, the first of which arrived in the U.S. the day before our deadline.
In the meantime, Rotax continues to offer compelling features via 2000-hour TBOs, a proven reliability record and that best-in-class power-to-weight ratio. For two-stroke fans, the 447 and 503 engines were discontinued in 2011; the 582 continues unchanged.
Rotax’s 912 iS has all the electronic injection and engine controls the market says it’s been waiting for. We’ll see how many are ready to pay for all this goodness.
Engine Trends
Although development is slow, there is still a demand from buyers for better fuel economy and especially for more power (what else is new?), and the industry is working hard to respond. For several years, the main talking point from Lycoming and Continental has been roller cams. This more-efficient technology is now well implemented in new engines, and the custom rebuild shops have developed their own take on retrofitting roller lifters to existing engines, so there’s little need to do without them.
What roller lifters do is reduce friction between the highly stressed cam lobe and lifter for a resulting gain in efficiency. A secondary, but still welcome, advantage is that roller cams are less susceptible to damage from corrosion caused by the number one killer of airplane engines, inactivity.
Looking like it’s going to rewrite the rulebook, UL Power has one of the newest, most advanced and widest range of sport aviation engines. With the introduction of its six-cylinder family last summer, UL Power now offers 97- to 200-hp engines fit to duke it out with everyone from Rotax in the LSA market to Lycoming et al. in the homebuilt field.
What Belgium-based UL Power doesn’t have is time in market. A new company, it sold its first engine in 2006 and there likely aren’t 50 UL engines flying in North America yet. But the company is well organized with diversified income and now enjoys an energetic U.S. distributor, so its numbers are growing faster than June corn. UL Power engines may become a familiar sight soon.
Technically, UL’s engines are the answer for those who have been crying for a “modern” engine. They follow the familiar air-cooled, horizontally opposed layout, but reviewing the details (see KITPLANES® June 2012 “Engine Update”) reveals their thoroughly modern design. Highlights are a seven-main-bearing crankcase, single-lever FADEC engine management and a power-to-weight ratio rivaling Rotax’s. Limitations are few: Electric props are the only practical controllable pitch option so far (the crankshaft is hollow and could transmit oil, but there is no provision for a hydraulic prop governor); there’s no ability to select economy or power modes (you get whatever the computer is programmed for), and there’s a need for redundant batteries and fuel pumps, as with all electronic fuel injection.
That said, UL’s numerous advantages have attracted wide attention across the industry and numerous fitments, and FWF kits are appearing. UL engines vary the specifications by juggling two strokes, two compression ratios and the number of cylinders (four or six). We’re listing the eight most popular combinations; not listed is the UL350iHPS, a fan-cooled, 150-hp, high-rpm variant for helicopters or pushers.
UL Power 350iS.
Another significant bump in efficiency comes from the movement by the more experimental among us to higher compression ratios. This isn’t Lycoming’s and Continental’s favorite subject, as they view the increased stress on fundamental engine parts such as the pistons, rods, crankshaft, bearings and case as outside of their comfort zone, but the custom shops have broad experience with 9.5 and 10:1 compression ratios and they’re not losing any sleep over it. There’s no consensus whether these bumps in compression reduce the time between overhauls. Some shops say TBO is unaffected, while others disagree by an unspecified amount, which we take to mean several hundred hours, so that’s something to discuss with your engine builder. On the other hand, the increase in performance is indisputable, especially for those cruising in the 7000 and up altitudes. The gain in speed, climb and fuel economy at altitude makes a bit of compression the poor man’s turbo-normalizing.
Very much part of the Experimental engine scene today is increased displacement. This trend has no clear-cut impetus behind it, say the engine shops, other than the general trend toward more horsepower. As always, there is no replacement for displacement when it comes to making power, as a few more cubic inches are almost always the least expensive, most dependable route to increased power. The extra inches are coming mainly from longer-stroke crankshafts, as the cylinder bores are already at their maximum in most aircraft engines. The poster child for the breed is the 360 Lycoming, stretched to a tad over 400 inches, though there are definitely other combinations available.
Jabiru 3300.
Putting the light in Light Sport Aircraft is Jabiru, the Australian engine and airframe builder with a bent for simplicity. Relying heavily on CNC machining from billet, Jabiru’s two air-cooled, direct-drive aircraft engines eschew complexity, and so are lightweight and cost competitive. Now in its 20th year, Jabiru has some 2000 engines flying in the U.S., and they are proven, understood and well-developed powerplants. In 2012, they even lost a couple of pounds thanks to the elimination of external oil lines to the valve train in favor of hollow pushrods.
Not to beat a hole in the simplicity drum, but the Jabiru really keeps the cost and complexity spirals in check. In fact, the 2200 and 3300 engines are nearly identical, differing only in that the 2200 is a four-cylinder and the 3300 is a six. Either 100LL or 91-octane mogas is acceptable.
U.S. sales and support are handled by Jabiru Sport Aircraft in Tennessee, which has developed a large number of firewall-forward kits to speed Jabiru installations on the Zenith 601, 650, 701 and 750; RANS S-6, S-7S and S-19; Van’s RV-12, Kitfox, Avid Mk 4 and the Arion Aircraft Lightning. Prices for the FWF kits vary, but hover around $4,000 and typically include a battery and carb-heat boxes, fixed-pitch prop, spinner, oil cooler, cowl and more.
There are several meaningful advantages to stroker engines, not the least being the bigger engines fit in the original engine’s footprint, so there is no need to enlarge the cowling, change the cooling baffling or deal with other fitment issues. Furthermore, the larger-displacement engines gain little weight in the processes, so performance isn’t compromised by increased mass.
The downsides are that strokers cost more and drink a little more fuel, so big displacement is more of a power grab than an increase in efficiency. Interestingly, the shops report no loss in TBO due to the larger power pulses. After all, in a typical 400+-cubic-inch four cylinder, each cylinder is a little over 102 cubic inches, or the displacement of an entire economy-car engine. That’s a lot of bang per power stroke.
As recently reported in KITPLANES® (March 2013 issue), one fallout from the Red Bull air races was a movement to lighten aircraft engines by trimming excess weight from internal parts such as pistons and pins, along with cutting of unneeded bosses, lightening flanges and using lighter-weight accessories. The Red Bull competitors were looking for snappier turning, but aerobatic and backcountry pilots appreciate the overall increase in performance too.
Buying an Engine
Engine manufacturers and rebuild shops say the majority of complete Experimental engine purchases are by kit aircraft builders, which logically leads to the airframe kit manufacturer as the source for engines. In fact, Lycoming, which embraces the Experimental engine market, has specific part numbers for several of the more popular kit planes. Lycoming labels these specific engines OEM Experimentals because they are, in essence, the Original Equipment Manufacturer engine for that kit aircraft, yet are Experimental engines as far as the FAA is concerned.
In the lead in this regard is Van’s Aircraft, which makes engine selection as easy as ticking off another box on the order form. This is often a cost-effective decision because the engine is guaranteed to be correct for the airframe. The aggravation and time lost to chasing down small parts, or dealing with difficult-to-foresee surprises, such as a magneto that wants to be in the same place as an engine-mount tube, are avoided, and generally life goes much more smoothly.
Thanks to its high volume, Van’s can offer competitive pricing on both certified and Experimental engines. And as you’d expect, Van’s, Glasair and other kit makers are excellent sources to consult when it comes to selecting accessories such as induction and exhaust because they know what fits their engine mounts and airframes.
Experimental engines all offer long option lists for things such as custom paint, electronic ignitions and higher compression ratios. Typical of the breed is this OX-360 Titan on display at AirVenture.
Otherwise, the traditional path to engine ownership is an engine shop such as Aero Sport Power, Barrett Precision Engines, Eagle Engines and Ly-Con Aircraft Engines, to name a few. These specialists are dealers for the two OEMs, plus the ECi and Superior lines (often for all four), plus they offer a wealth of knowledge about what works, what doesn’t and what’s cost effective. Also, most are dealers for accessories such as starters, magnetos, etc., and can handle custom installations and accessory service long after the initial engine sale. These shops are where the innovations such as adjustable oil-pressure relief valves and cold air intakes come from too. In short, if it’s firewall forward, these guys know what’s up.
The Hirth F-23 50-hp two-cycle. Recreational Power offers a variety of engines for light aircraft, all with AI-Nikasil coated cylinders.
Another major plus for an engine shop is engine break-in. For our money and hide, the $1,000 it typically takes to have your engine installed on a dyno and run-in by a pro is the best insurance policy going. It allows for making that first flight knowing it isn’t your engine’s first time running, it isn’t leaking, infant mortality isn’t lurking in the magnetos or carburetor, and above all, it frees the test pilot from the overwhelming task of simultaneously evaluating a new airframe and breaking in a new engine. Traditional aircraft engines hate low-power operation during run-in—it’s begging for glazed cylinders—yet do you really want to blast around in your new speedster at a minimum of 75% power on the first flight? Half a day on the engine dyno means your powerplant has a good start on break-in and already has its first oil analysis done before the tires leave the runway.
It’s guaranteed you’ll want the engine on the airframe long before the first flight to install systems and fit the cowling, and that means a long time between the engine dyno and first flight. To avoid corrosion, have the engine shop “pickle” the engine with preservative oils.
Still Cloudy, But No Turbulence
After transiting several years of nasty economic cumulonimbus, the recent stability and occasional modest profitability reported by traditional engine makers is comforting. Likewise, Lycoming’s drone business bodes well for electronic engine controls actually debuting from the OEM giant.
In the meantime, Rotax and UL Power are already there. They look to mark 2013 as the breakout year for electronics in Light Sport and compact two-seat sport planes. One wonders how long it might take the higher-powered examples of these engines to move into the Van’s Air Force heart of the kit-building movement?
Engine-savvy visitors at AirVenture last summer feasted on the Raikhlin Engine Development (www.red-aircraft.com) RED A03 V-12. Displayed on a simple stand, the all-new engine slots below turbines and above the deepest-breathing Continentals and Lycomings with a 500-hp takeoff rating. It is aimed at drone, ag, warbird replica and light turboprop markets. It would also make a nifty prime mover in some playboy’s composite go-fast.
Raikhlin Engine Development’s diesel V-12 has the look and detailing of a world-class automotive race engine.
Debuted at AERO 2010 in Friedrichshafen, Germany, the engine has been in development since 2009 but had not been previously seen in North America.
Displacement is small at 374 cubic inches (6134cc), but turbo boost makes up the rest. The hardware specs are a wish list of four camshafts, four valves per cylinder, dry sump oiling, common rail diesel (Jet A) fuel injection and FADEC single-lever control. Sitting there in the aluminum, it’s almost like a WW-II-era Merlin or Allison downsized and modernized for the 21st century.
Designed from the beginning strictly to swing a prop, the A03 V-12 incorporates a built-in, RED-designed 1.88:1 prop-reduction gearbox and combination dry sump oil tank. The tight tank packaging means no provision for hydraulic propeller control, so only electric props may be used.
Complete redundancy is provided, so there is more cozy packaging for two alternators, two fuel pumps, two coolant circuits and two engine-management computers (mounted off-engine). Compression is a low 16.5:1, indicating generous boost from the twin Garrett turbos is planned. This implies intercooling chores for the airframe liaison engineer; RED develops a specific PSRU output shaft to control propeller torsionals for each application.
Silver Atena, a large OEM supplier of automotive electronics, developed RED’s sophisticated engine management computer. Using 115 I/O channels, the engine-control unit (ECU) runs each bank of the V-12 separately. It also provides data acquisition for fault detection, plus intelligent failure management, should anything go wrong.
So far nothing untoward has happened, according to RED. Dyno and flight testing in a Yak 52 have proved the accuracy of performance projections. European certification testing began in August 2012, with FAA certification to follow. As of last summer, RED said it had already built a total of 20 V-12 engines in three development batches.
Overall the RED V-12’s layout and detailing simply ooze high-end motorsports, and unsurprisingly, several RED principals boast Le Mans and F1 auto racing experience. Most notably, Chief Engineer Norbert Kreyer was general manager of Toyota’s F1 V-10 engine program from 2001 to 2004. This also shows in the RED V-12’s low mass. All-up with propeller, coolant, etc., the installed weight is reported at approximately 850 pounds.
Equally impressive are the quoted fuel-consumption figures of an astonishingly low 25 gph at takeoff, and 15.5 gph at 400 hp in economy cruise at sea level. That’s a claimed brake-specific fuel consumption (BSFC) of 0.339! Besides the 500-hp T.O. rating, RED lists 460 hp as maximum continuous at altitude (BSFC of 0.355). Clearly real-world fuel-consumption testing will be something to see.
Raikhlin Engine Development was founded in 2008 and is headquartered near the famed Nurburgring racetrack in Adenau, Germany. Owner Vladimir Raikhlin is Russian, and Russia is also the source of much of the private investor funding. Baltic, German and other European investors are also involved. The company says the V-12 should go on sale in 2013; preliminary pricing is estimated at $185,000 per engine. This will change depending on build volume, so pray for government contracts!
Another moving target is TBO. Initially the EASA requires a low 800- to 1000-hour overhaul time. As experience grows, RED expects 2000- to 3000-hour TBOs. Furthermore, when RED returns to Oshkosh this summer, the company plans to show a V-6 built from half of the V-12.
—T.W.
TRACE V-8
Big-engine fan boys may recall the TRACE V-8, now out of Midland, Texas (www.traceengines.com). This 494-cubic-inch V-8 boasts roots all the way back to the mid-1970s, when big-block Chevys roamed North American racetracks in the Can-Am race series. Starting as the Thunder engine, then further developed by Orenda and now TRACE, little remains of its automotive heritage; it is a pure aviation unit with built-in prop-speed reduction unit (PSRU) and 600-hp takeoff and 500-hp max continuous ratings. An Experimental version with a special camshaft has raised power to 750 hp.
To many, the Thunder/Orenda/TRACE experience has been the great hope for piston-engine replacement of ancient round motors or eye-wateringly expensive turboprops. It’s proved an incredibly long, expensive and mechanically troublesome journey, but in the end, the big V-8 delivers on its promise of massive fuel, maintenance and acquisition cost savings to commercial operators. As such, TRACE the company seems to stay busy certifying firewall-forward kits for ag and charter aircraft, but not sport planes. An exploratory display at the Reno Air Races netted no interest in 2009, turning the company back to its core commercial market. But it still offers a ready powerplant in the elusive 500+ power level for those with a real need for speed.
—T.W.
Specialty-engine fans have been keeping an eye on a new Lycoming parallel-valve cylinder for 360 and 540 engines. Under development by Andy Kanehl of Phoenix Power Products (262/255-0800) and to be sold through Barrett Precision Engines, the new cylinder is a radical departure from standard practice and, for a price, promises a new level of power and efficiency.
Keys to the new cylinder are all-new intake and exhaust ports developed by Kanehl. The new ports share nothing with Lycoming’s, utilizing a D-shape for a flat port floor along with an overall raised height for a more gentle short-turn radius. These changes improve breathing, yielding a fundamental increase in performance and efficiency.
In the combustion chamber, two flat quench areas have been added to promote motion in the air/fuel mixture and thus suppress detonation and generate more complete burning of the mixture. Other improvements are more extensive cooling fins between the valves, and high-quality valves contoured for superior airflow, made taller to mate with the vertically deeper ports and longer valve guides.
To accommodate the raised ports, the cylinder is an inch taller than a stock parallel-valve Lycoming, or 5/8- inch shorter than an angle-valve cylinder, depending on how you want to look at it. Of course this means a 2-inch-wider parallel-valve engine, along with the need for longer pushrods and pushrod tubes, plus reshaped oil drain-back tubes to match. Phoenix Power Products is currently developing all of these necessary parts.
Carryover items are the stock rocker arm and shaft.
The taller cylinder also means more surface fin area for improved cooling, along with the need for longer intake tubes. Also, the better-breathing cylinder heads will make intake and exhaust choices more critical. Kanehl is working on adapting all currently available cold-air intakes to his cylinders and has been testing exhaust systems to determine the most efficient pipe lengths and diameters.
Phoenix is also making its own cylinder barrels with tapered fins. Weight is up for the complete cylinder assembly compared to a stock parallel-valve jug, but is 3-5 pounds lighter than an angle valve.
To date, a first batch of 24 production cylinders has been completed and a second batch of 100 cylinder heads has been cast and machined and is ready for the second batch of cylinder barrels. Preliminary testing on one 540 was done on Barrett’s engine dyno, and at our deadline, Phoenix was installing an engine dyno in its Menomenee Falls, Wisconsin, facility to allow extended durability testing.
The preliminary testing at Barrett showed the cylinders easily make 315 uncorrected horsepower in the Oklahoma heat (at 90˚ F or more) and humidity; a power rating of 340 hp seems reasonable with a stock displacement 540. Kanehl also reports his cylinder cools better than stock and responds eagerly to aggressive leaning, which we’d expect given the fin, porting and quench improvements.
As you’d assume, these are not inexpensive cylinders, at $3,200 apiece (includes the piston, rings, pin and valves, plus assembled springs and retainers), but Kanehl believes they will compete favorably against angle-valve cylinders or large-displacement options such as 580s or 390/400-inch four-cylinders. Kanehl figures on aerobatic and some backcountry aviators as the target market for his high-performance cylinder, a niche used to dealing with the custom nature and higher costs of such installations. Phoenix expects its cylinder to be on sale this summer.
—T.W.
