Vibration-Free 2-Stroke ICE Tech Returns in Hybrid Powertrain

Two-stroke internal-combustion technology could be making a return to mainstream powertrain production thanks to a new motor claiming to be as smooth as the benchmark V-12.

Austro-German powertrain innovation company, the Obrist Group, claims its new mini powerplant achieves the “champagne” zero-vibration standard where a glass of wine can be balanced on a running engine without spilling.

The company sees the compact engine being used as a “Zero Vibration Generator” coupled with hybrid electrified powertrains such as its HyperHybrid concept system.

As with some other hybrid generator systems, the Obrist engine is not connected to the vehicle's drivetrain at all but is used solely for power generation, feeding an electric motor that drives the vehicle via a compact buffer battery.

Its mini generator weighs just 242 lbs. (110 kg) and claims 60.3 hp running constantly in an optimum rev range. It is a 1.0L naturally aspirated ICE with multi-channel fuel injection. As such, there is no need for the complication of variable valve timing, which is common in drive engines.

Its two crankshafts operate in opposite directions, eliminating any vibrations. A rubber-damped gearbox on the second crankshaft minimizes the noise generated by the gearbox. An integrated flywheel compensates for the inertias of the rotating parts, including external forces outside the engine, such as the oil system with the oil pump. As a result, and with the unit housed in a soundproofing box approximately the size of a shoebox, the engine is billed as virtually noiseless and vibration-free.

When used with Obrist’s HyperHybrid powertrain, the system claims a purely electric range of more than 50 miles (80 km), enough for 90% of everyday trips. Test mules running the system using gasoline or carbon-neutral e-fuels claim fuel consumption of 157 mpg (1.5 L/100 km), providing an overall range of more than 620 miles (998 km) between refueling.

Obrist founder Frank Obrist says: “HyperHybrid combines the advantages of electric mobility with the simplicity of the familiar refueling process, thereby solving the problem of range anxiety that is inherently associated with electric cars.”