When it comes to modifying a classic air-cooled Volkswagen Beetle, most purists will upgrade to a slightly larger flat-four engine or perhaps dabble in a Subaru swap. But the chaotic mechanical minds at the YouTube channel CarsandCameras decided to go in a completely unhinged direction: stripping out the factory motor and replacing it with a screaming 670cc two-stroke engine ripped out of a vintage snowmobile."Today this Volkswagen Baja Beetle is getting three times the factory power output with an engine that's just half the size," the host announced at the start of the build.Going from the factory 40 horsepower to an estimated 120 horsepower on a lightweight Dune Buggy chassis is a recipe for absolute disaster. "We're going to absolutely destroy this transmission… maybe we will, maybe we won't," they laughed.The Tapered Shaft ProblemDropping an Austrian-built Rotax snowmobile engine into a German car chassis presents a massive engineering hurdle. Unlike most industrial engines that feature a standard keyed shaft, the snowmobile engine utilized a tapered output shaft.To connect the 120-horsepower engine to the Beetle's manual transmission, the team had to completely fabricate a custom adapter. Because they couldn't perfectly machine a tapered hole, they cut the center hub out of the original snowmobile clutch and attempted to press-fit it into a custom steel collar using a 20-ton hydraulic press and a thermal "heat and freeze" expansion method.When the press-fit proved to be slightly too loose to handle 120 horsepower, they resorted to drilling holes and filling them with heavy "rosette" welds to bind the adapter permanently to the shaft.Add in a massive aluminum radiator sourced from a '65 Mustang to handle the liquid cooling, and the Frankenstein build was finally ready to run.Pull-Starting a VolkswagenBecause the snowmobile engine did not come with an electric starter, the CarsandCameras crew was faced with one of the most hilarious realities of the build: to turn the car on, they had to stand behind the bumper and rip a pull-cord."Wait, this thing's a pull start?" one of the hosts realized in disbelief."You ever pull-started a car?" another joked before violently yanking the cord to turn over the entire engine, flywheel, and transmission assembly.After battling flooded carburetors and a few fuel leaks, the massive two-stroke finally roared to life, emitting a thick cloud of blue smoke and a deafening, chainsaw-like idle.The Narrow Power BandTaking the lightweight Baja Bug out for a shakedown run on the gravel road proved just how violent 120 two-stroke horsepower can be. When the driver mashed the gas pedal, the buggy ripped down the dirt path, spinning its tires effortlessly."When that power band kicks in, oh my god it's fast," the driver yelled over the screaming exhaust.However, they quickly discovered a major quirk of using a snowmobile engine with a manual transmission. Because snowmobiles use a Continuously Variable Transmission (CVT) to keep the engine RPMs locked at maximum power, the engine's power band is incredibly narrow."The power band, when it kicks in, it feels great, but it's only a short distance. You can tell it's tuned for a CVT," the driver explained. "When you hit second gear, [it] falls flat on its face again until you hit the power band again, which takes forever".Despite the peaky acceleration, the team deemed the chaotic engine swap a massive success. The adapter held, the transmission survived, and the two-stroke Beetle lived to see another day. With some serious carburetor tuning in the future to widen the power delivery, they are already eyeing a trip to the local drag strip to see if their 670cc snowmobile buggy can outrun a modern car.