Jay Leno attempts to win a Datsun 510 by guessing its weight

The Datsun 510 is quietly getting more popular in the collector market, but thanks to its sizeable production run the punchy little Japanese car can still be found and enjoyed for a reasonable price. One such example is the khaki-painted two-door owned by Jonathan Lessner which visited Jay Leno’s Garage this week—and almost ended up in Jay’s collection.

The 1970 model has an understated stance and paint, but the interior and engine compartment show that this car is all business. Lessner has been working on this “five-and-dime” since 2015, when he finally rounded up enough cash to buy the car he desired since childhood. He mixed in a bit of his own taste as he completed the build on this car.

The big change is the engine. This 510 had its L-16 four-cylinder yanked in favor of a KA24E sourced from a Nissan 240SX. Though it’s not the hotter KA24DE that sports a turbocharger, the single-cam KA24E is still a significant boost in power over the factory mill. The engine is backed by a five-speed transmission as well, giving the import coupe better cruising manners with the addition of an overdrive.

The shell and drivetrain are pretty lightweight, and the interior is sparse, sporting just two vintage Recaro seats, a bolt-in roll bar, and three additional modern gauges. When asked the overall weight, Lessner tosses out that he thinks the total weight is sub-2000 pounds. Jay seems skeptical, and plays along with a friendly bet for the car as they drive over to the other side of the shop to put the car on the scales.

Lessner seemingly stripped all the sound insulation, because between the engine and road noise the car sounds pretty darn loud. That extra bit of weight savings didn’t tip the scales in Lessner’s favor for the wager, as Jay wins the impromptu game of ‘guess the weight,’ with the car settling in at just over 2200 pounds. Still light by modern standards, but a few hundred higher than what Lessner predicted. Obviously, Jay let Lessner keep his car and settled for the satisfaction of winning the bet.

The additional road noise must not bother Lessner, though—after all, he built the car to drive it. He also has plans to autocross and track the 510 in the future. With the chunky 225-series tires and disc brakes on all four corners combined with the engine swap, it has all the makings of a fun car to whip around just about any track or parking lot course.