4 Of The Most Powerful Rotax Engines Ever Made For Aircraft

For the better part of the past century-plus, Rotax has been one of the most prominent names in the small aircraft engine market. While the company has changed its base of operation several times since its founding in 1920, Rotax has never wavered in its dedication to producing powerful, reliable engines for vessels like light aircraft and single-engine airplanes. If Rotax bosses have their way, the company will no doubt continue in that endeavor throughout the Century ahead. 

Over the years, Rotax has developed and manufactured dozens of different engines that have helped light aircraft enthusiasts and airplane home builders across the globe take to the skies. Of course, the aviation game is a far cry from what it was 100 years ago. As times have changed, so too have the power needs of even the smallest of aircraft. Rotax has, in turn, continued to refine its own engines to meet the needs of the times. The company has expanded the reach of its engine market, having developed powerful builds for other small vehicles like snowmobiles, jet skis, and side-by-side UTVs. They've even powered KTM motorcycles.

At the moment, the manufacturer continues to build engines to meet the needs of vehicles in all of those market segments. And yes, a few of those engines rank among the most powerful Rotax has ever made. 

Given Rotax's long history of manufacturing engines for aircraft, it seems only fitting to begin with one of the more powerful offerings in its current lineup of builds made to give flight to light airplanes. Among the offerings in that line, the 915 iS engines are pretty punchy, to say the least, offering light aircraft aviators an impressive 141 horsepower at 104 Kw. 

Most Rotax aircraft engines are largely designed for 600+ weight class CS-23 and CS-24 models, and the 915 iS models are no different. This four-stroke piston build also boasts four air and liquid-cooled cylinders and is touted alongside other Rotax engines as boasting best-in-class power-to-weight ratio. Yes, Rotax's 915 iS engine is also equipped with a turbocharger, which is largely responsible for its robust power output. The engine also offers 12 or 24-volt electric starter options and packs a 24v power supply that can produce up to 800w of energy, leaving plenty of room to power vital instruments and potentially even an extra gadget or two.  

The 915 iS also comes with an Engine Management System (EMS) that should help with fuel economy and overall performance, an option that will no doubt be of use when operating at a maximum altitude of 23,000 ft. And with an estimated TBO (Time Between Overhaul) of 1200 hours, this Rotax should safely keep your plane in the sky for years before it's time for a revamp. 

Just FYI — the 915 iS is not currently the most powerful engine in Rotax's small aircraft line. That title actually belongs to the 916 iS/c, which, at a surface level, has a lot in common with the 915 iS. For instance, the 916 is also a four-stroke piston design with four air and liquid cooled cylinders. It also comes with redundant electronic fuel injection and a turbocharger, as well as an EMS, an electric starter, and a 24-volt power supply that might allow for extra creature comfort in the cockpit.

Apart from those similarities, the 916 iS/c is a very different animal, and, unlike the two-seat friendly 915 iS, it is designed with 4-seat aircraft in mind. Yes, that means the 916 iS/c requires a little more power than its counterpart and is capable of pushing the ponies up to 160 HP while producing up to 142 ft-lb of torque. Perhaps more impressive than that uptick in power is that Rotax's engineers managed to deliver it without adding too much weight, with the 916 iS/c clocking in at 85.8 kg (or about 189 lbs) to the 915's 82.2 kg (or 181 pounds).

Those stats have led Rotax to label its potent 916 iS/c as both a "milestone" and a "masterpiece" of small engine ingenuity. It's easy enough to see why they're so proud of the build, particularly as it also boasts a TBO of 2,000 hours.

As noted, even as the aviation arena remains a sweet spot for Rotax, the company has indeed looked away from the skies to help power vessels bound for both land and sea over the years. As for vehicles in the former category, at a whopping 240 horsepower, the engine Rotax designed to power Can-Am's Maverick R side-by-side UTV — which, for the record, is dramatically different than an ATV — is easily one of the punchiest it's ever made. 

In fact, according to Can-Am, Rotax's turbocharged 240 HP 999T power plant is actually providing industry-leading power to its Maverick off-roader. The engine's dynamic output is only bolstered by the inclusion of Rotax's 54 mm tubeless turbocharger, and the build's actuated wastegate — a device that helps regulate the turbocharger's boost pressure — is apparently a first for the side-by-side sector.

On top of that, the inline three-cylinder, four-stroke, fuel-injected engine is also the first of Rotax's off-road power plants to utilize a seven-speed Dual Clutch Transmission (DCT), which is available in automatic or paddle shifter. Coupled with the engine's dedicated drive modes, it makes it possible to tailor the driving experience to whatever you need on the day. With a trove of design features meant to bolster the engine's durability in the wild, you should be able to tackle whatever high mountain roads or dusty dunes you tackle in your Maverick R without worrying too much about damaging the powerful engine, giving it all that get-up-and-go.  

With Rotax providing some serious punch to the land-bound Maverick R, the manufacturer has developed an even more powerful engine for vessels primarily used in the open waters of the world. Said vessels are made by Sea-Doo, who has been manufacturing personal watercraft (PWC) for the thrill-loving masses since 1968. Despite a lengthy history in the water sports arena, the Sea-Doo may have reached its peak when it recently began offering the Rotax 1630 ACE 325 engine in certain jet skis, with that engine capable of producing a staggering 325 horsepower.

At present, that powerful Rotax is only available as an option for three models of Sea-Doo: the RXP-X, the RXT-X, and the GTX Limited. As for that 325 HP, per Sea-Doo, it is indeed a record-setter in the personal watercraft game, with the purpose-built 1630 ACE 325 currently standing as the most powerful engine ever built for a PWC. Just for reference regarding the engine's power capabilities, the 1630 ACE 325 is capable of providing a Sea-Doo with legitimately head-spinning acceleration, going 0 to 60 mph in just 3.4 seconds.

It is, of course, worth wondering whether or not your average Sea-Doo rider actually needs or can even safely handle the sort of acceleration the Rotax engine delivers. But if you're a seasoned PWC enthusiast looking for the ultimate ride or a racer looking for a competitive edge on the water, the 1630 ACE 325 should more than suit your needs.