The 2016 Sea-Doo lineup was easily one of the most anticipated PWC lineups in history. Rumors of a 300-plus-horsepower Sea-Doo powerplant were tossed around for months, and fans were certainly not disappointed to hear about the new 300 horsepower 1630 ACE Rotax engine being dropped in the Sea-Doo RXP-X, RXT-X, and GTX performance models.
Sea-Doo upped the displacement from 1494cc to 1630cc. They also have swapped to the extremely efficient and innovative ACE (Advanced Combustion Efficiency) engine design, similar to what is used in the entry level Sea Doo Spark. But unlike other BRP utilized ACE engines, the 1630cc retains a single camshaft, rather than a DOHC design.
In addition to the displacement increase, the pistons are 20 grams lighter. Connecting rods are also lighter, albeit shorter as well. Also cutting down on weight, the heavy steel cylinder sleeves have been replaced by plasma coating. The engine’s cylinder head also underwent some revisions, featuring a redesigned combustion chamber quench, larger injectors, and new ignition coils that produce double the ignition energy for a hotter, cleaner and more efficient burn.
The supercharger was significantly improved over the previous supercharger, which is a big reason for the 40 horsepower increase. It features a lighter, more efficient 32-blade supercharger wheel, which is capable of producing a whopping peak 18psi. Sea-Doo also wanted to make this supercharger more durable than the previous, so they equipped the blower with 8 steel washers and two composite composite bearing packs on each end of the near 1-inch thick supercharger shaft. According to Sea Doo, this supercharger is 100% “maintenance free.”
Of course, the biggest factor directly responsible for the new ACE Rotax’s gain in horsepower and engine efficiency is the dramatic improvements made to the core’s cooling and internal temperature management. Coolant and oiling passages are increased, a massive external oil cooler dwarfs the outgoing unit, and the intercooler is literally twice the size of the previous unit and is made from superior materials for greater longevity and added performance.
