Water and combustion engines generally have a complicated relationship. A little rain is harmless, but getting sufficiently deep can turn an ambitious river crossing into a very expensive recovery operation.
Horse Powertrain has developed an engine specifically for drivers heading considerably deeper. On paper, it looks like a fairly conventional turbocharged 2.0-liter four-cylinder designed for hybrid SUVs and pickups.
Its party trick only becomes apparent when the road disappears beneath the water. Because this engine is designed to continue operating while fully submerged, rather than simply surviving the occasional splash.
Called the B20, the new engine can operate at depths of up to 1.1 meters, or roughly 3.6 feet. That’s enough water to make most drivers seriously reconsider whether they should continue forward.
Horse Made The Entire Engine Waterproof
The B20 carries an IPX8 waterproof rating, with Horse Powertrain using a fully sealed structure to protect it during deep-water operation. Dedicated sealing between the engine and transmission helps keep water out, while electrical components and sensors are also designed to meet IPX8 requirements.
Those sensors continuously monitor the engine’s surroundings. When the system detects that the B20 is submerged, its control software can automatically alter throttle response or restrict power depending on the conditions.
Of course, having an engine capable of operating underwater doesn’t automatically make the entire vehicle waterproof. Cabin sealing, electronics, air intake positioning, and numerous other components still determine how deep a particular SUV can safely wade.
It Makes Up To 248 HP
Waterproofing isn’t the B20’s only interesting feature. The direct-injected 2.0-liter turbo produces between 188 and 248 hp depending on specification, along with 300-380 Nm (221-280 lb-ft) of torque.
The 130-kg (287-pound) engine is intended primarily for hybrid, plug-in hybrid, and range-extender applications. Horse says it can also function as a generator in a range-extended EV rather than directly powering the wheels.
Its Miller-cycle combustion process, high-tumble intake ports, and specially designed pistons contribute to a claimed thermal efficiency of around 48 percent. Horse also says the engine can support vehicles tackling a 100-percent grade, equivalent to a 45-degree incline.
It’s Already Going Into Production
This isn’t simply an engineering prototype built to look impressive in a water tank. The B20 has already found its first application in the Chinese-market Geely Galaxy Cruiser 700.
In the rugged SUV, the engine forms part of a plug-in hybrid system and works with Horse Powertrain’s three-speed hybrid transmission. The combination is intended to give electrified off-roaders the capability expected from serious combustion-powered 4x4s.
An Engine Built For The Deep End
Modern off-road vehicles increasingly combine electric motors and batteries with combustion engines, creating new engineering challenges when owners venture into difficult terrain. Horse’s solution is to make the combustion side of the equation unusually resistant to one of off-roading’s biggest hazards.
The B20 won’t magically turn every SUV using it into a submarine, and attempting to drive through floodwater is still extremely dangerous. In a properly engineered off-roader operating within its specified limits, however, knowing the engine itself can keep running beneath 1.1 meters of water is an impressive capability.