A Lot Of Engineering In A Little Car


I’ve often wondered what might happen to these all-electric cars when the batteries are toast. Much like a fuel-powered vehicle, when the engine is gone, they sell for pennies on the dollar.

-By Kelly Kirk

Derek Young of San Francisco picked this Nissan Leaf up for a steal because the battery had no range left, only around twenty-five miles. As an all-electric car, that range makes it almost worthless and the perfect candidate for recycling, or in this case, up-cycling into something that is kind of cool. Derek seized the opportunity and got to work.

The back of the car was fitted with the modified rear subframe from a Lexus IS350, and a Kawasaki ZX-10R motorcycle engine was mated to it with a chain-driven Quaife differential. With the stock electric powertrain remaining up front and the motorcycle engine now installed out back, the Leaf was legitimately all-wheel drive and technically a hybrid. Although I don’t fully understand how it works, a knob on the dash allows the driver to go from all-electric front-drive to hybrid all-wheel drive to fuel-only rear-drive. It’s such a wild concept.

Obviously, the Leaf brakes weren’t up to the task of slowing the speeds that the sport bike engine was capable of, so a simple brake upgrade was in order. Out back, the Lexus IS350 brakes that came with the subframe were deemed sufficient, but up front, Mustang rotors are clamped down with Nissan 370Z calipers.

Although the easy thing to do would be to just have the engine out in the open in the back, that would make the passenger compartment incredibly hot, loud, and smelly, no matter how well-tuned. To help with this, a piece of acrylic is installed in the same fashion as in a taxi or a cop car. Fresh air is fed to the radiator through a side scoop installed where a window would typically be, and hot air exits through a flap in the rear. Although it mostly lives on the track, I believe it can also be driven on the street.

Motorcycle engines in cars fascinate me. They make great power-per-inch, and they’re light, but they lack appealing torque due to their small size. I remember a picture of a Ford coupe with a Harley V-twin in it, and although it was unique and likely sounded great, I’m sure it was too much car for that engine. British car enthusiasts have also embraced modern motorcycle engines due to their small size, lightweight, and high-rpm horsepower. I’ve watched a lot of videos and read a lot of write-ups, as I’ve had an engineless British car sitting around forever. It seems like a fun swap, but only at ultra-high speeds. As someone who isn’t against cutting a hole in the hood (it’s already cut, FYI), I’m still leaning toward a big V6 or small V8.

This Leaf has the advantage of electric torque to pull it until the engine can get revving to make the big horsepower. If you’ve got a car that you want to put a motorcycle engine in, or if you’re looking for a differential setup for almost anything, check out Quaife. They make a lot of really cool stuff that I would never have expected to see.