ROTAX Engines
Posted: Tue Aug 31, 2021 9:31 am
As a corollary to the recent discussion about the SEA DOO SWITCH boat as the new product from BRP that came from the their Project-M development, the new boat uses a ROTAX four-stroke-power-cycle engine, built by BRP's other engine maker, ROTAX of Austria.
ROTAX has been making modern small four-stroke-power-cycle engines for aircraft for 100 years. In terms of engine reliability, engine weight, and engine power-to-weight, an aircraft engine would seem to impose more stringent demands than an outboard engine. If an outboard engine fails in service, the boat continues to float, whereas an aircraft engine that fails in service presents a much more serious obstacle to a safe return to the ground.
These ROTAX engines are also quite fuel efficient, to the point that they have been used in military drone aircraft where long flight endurance is a very desirable characteristic. The smaller drones used a ROTAX 912 iS engine, which produces 100-HP using a four-cylinder-opposed design, uses fuel-injection and an electronic engine management module, has a rating of 2,000-hours between recommended overhaul, and has been see in some crashed drone wreckage photographs. For example, visit:
https://www.recreationalflying.com/uplo ... 1071c.jpeg
Once Bombardier found out that some non-US countries were using ROTAX engines in their military drones (notably Turkey), they stopped exporting them to those countries.
The 2,000-hours between recommended overhauls is also a very attractive specification. I don't know exactly what an aircraft engine "overhaul" consists in. (For some guidance, see the FAA Advisory on that topic.) In terms of service life, 2,000-hours would be reasonable for me as a recreational boater. My E-TEC engine is now in its 13th season of use and is still only at 535-hours of running time. Extrapolating my pattern or use of my boat to 2,000-hours suggests that I could get 48 seasons of recreational boating out of a ROTAX engine rated for that much use "between overhauls." However, I infer from the existence of "100-hour maintenance kits" that the ROTAX aircraft engine does need some attention every 100-hours.
The SEA DOO SWITCH uses a larger three-cylinder 1.630-liter engine which can produced up to 230-HP output without supercharging, and 300-HP with supercharging. For comparison, the Mercury four-cylinder in-line 1.7-liter VERADO with supercharging was sold at a top horsepower rating of 200-HP. To get 300-HP from the VERADO engines Mercury switched to a six-cylinder in-line 2.7-liter displacement engine, which they have since boosted to 400-HP in special race versions.
Even the non-supercharged 230-HP engine seems to be producing a lot of horsepower per liter of displacement: 140-HP per liter is no slouch.
Is there something from BRP in the future in the way of using their ROTAX engines in boats other than jet-skis? Again, one would have to think that putting a ROTAX engine on the transom of a BRP boat would be more profitable to the BRP corporation than buying engines from Brunswick to put on them.
ROTAX has been making modern small four-stroke-power-cycle engines for aircraft for 100 years. In terms of engine reliability, engine weight, and engine power-to-weight, an aircraft engine would seem to impose more stringent demands than an outboard engine. If an outboard engine fails in service, the boat continues to float, whereas an aircraft engine that fails in service presents a much more serious obstacle to a safe return to the ground.
These ROTAX engines are also quite fuel efficient, to the point that they have been used in military drone aircraft where long flight endurance is a very desirable characteristic. The smaller drones used a ROTAX 912 iS engine, which produces 100-HP using a four-cylinder-opposed design, uses fuel-injection and an electronic engine management module, has a rating of 2,000-hours between recommended overhaul, and has been see in some crashed drone wreckage photographs. For example, visit:
https://www.recreationalflying.com/uplo ... 1071c.jpeg
Once Bombardier found out that some non-US countries were using ROTAX engines in their military drones (notably Turkey), they stopped exporting them to those countries.
The 2,000-hours between recommended overhauls is also a very attractive specification. I don't know exactly what an aircraft engine "overhaul" consists in. (For some guidance, see the FAA Advisory on that topic.) In terms of service life, 2,000-hours would be reasonable for me as a recreational boater. My E-TEC engine is now in its 13th season of use and is still only at 535-hours of running time. Extrapolating my pattern or use of my boat to 2,000-hours suggests that I could get 48 seasons of recreational boating out of a ROTAX engine rated for that much use "between overhauls." However, I infer from the existence of "100-hour maintenance kits" that the ROTAX aircraft engine does need some attention every 100-hours.
The SEA DOO SWITCH uses a larger three-cylinder 1.630-liter engine which can produced up to 230-HP output without supercharging, and 300-HP with supercharging. For comparison, the Mercury four-cylinder in-line 1.7-liter VERADO with supercharging was sold at a top horsepower rating of 200-HP. To get 300-HP from the VERADO engines Mercury switched to a six-cylinder in-line 2.7-liter displacement engine, which they have since boosted to 400-HP in special race versions.
Even the non-supercharged 230-HP engine seems to be producing a lot of horsepower per liter of displacement: 140-HP per liter is no slouch.
Is there something from BRP in the future in the way of using their ROTAX engines in boats other than jet-skis? Again, one would have to think that putting a ROTAX engine on the transom of a BRP boat would be more profitable to the BRP corporation than buying engines from Brunswick to put on them.