CHATSWORTH, Calif. — A vintage Fiat 124 Spider — so pretty you could pinch its little orange cheeks — accelerates up a canyon road in the San Fernando Valley. But there’s something strange about this Pininfarina-designed Italian roadster. First, it feels downright peppy as it chugs uphill. And there’s actually no “chugging,” but rather a spacey, high-pitched whir.

Inside this 1982 Fiat is a modern battery-powered drive system designed by Electric GT, a California company that has created a “crate motor.” Electric GT’s version of the crate motor, a term long associated with hot-rod gasoline engines sold in crates by automakers, allows professional restorers or even enterprising home mechanics to convert vintage gasoline cars to run on electricity.

“A lot of guys go out in a classic car that’s 40 or 50 years old, but it’s a one-way trip — they get a ride home with AAA,” said Eric Hutchison, who founded Electric GT in 2014 with a partner, Brock Winberg. “This is for enthusiasts who love their cars but want something reliable that’s good for a weekend drive.”

The company garnered attention when it took a junkyard 1978 Ferrari 308, perhaps best known as Tom Selleck’s car in “Magnum, P.I.,” and swapped out its V-8 engine for electric motors. So transformed, with nearly double the torque of its gasoline forebear, the Ferrari trimmed a remarkable 10 seconds per lap from its times at a Las Vegas-area racetrack.