Yes, keen Honda aficionados: not every Z pictured is a Z360, and not every Z pictured is a GS or TS variant from after 1971 (or so.)
But I'd like to talk about one very special engine fitted to a very special microcar coupe from back when the name Honda came after Soichiro, its founder. For those of you confused as to what Honda was trying to do with the modern CR-Z should look back to their first real crack at a sporty hatchback coupe.
Based on the Honda N360 microcar, the Z is rare as one of the few classic J-Tin cars that had been sold in the U.S. when new. Many of the rare and desirable models from Japan stayed within the borders of the small island nation because Japan's automakers preferred to create different cars for different markets.
Also surprising is that the U.S. and other export markets like the UK and Australia got a desirable version of the Z. Equipped with a 598 cc 2-cylinder single overhead cam engine, the coupe was advertised as making a punchy 36 horsepower. With just 595 kg (1,320 lbs) to lug around, performance would have been a few notches quicker in a straight line than the later 602cc Citroën 2CVs—but in corners, the Honda lacked the French icon's firm-as-cookie-dough suspension.
I have a feeling you've already concluded the Z wouldn't have been too popular in muscle car-loving America, and you'd be right. But its diminutive size and jewel-like construction quickly made many Japanese buyers happy, where it was classified under tax and license-friendly kei car regulations when equipped with its smaller 354 cc engine.
But Honda, the world leaders in motorcycle technology and a former Formula 1 constructor couldn't just leave the base engine with 31 horsepower alone. For the really hot Z trim levels, buyers got a 5-speed manual transmission and a revised 354 cc engine that made 36 horsepower at 9,000 rpm. Honda eventually added water cooling (benefitting reliability and emissions) to the sewing machine-like powerplant, but its output and maximum rpm stayed the same.
Though just a 500 rpm and 5 horsepower bump over the base versions, I find it amazing that Honda took an engine related to those in its motorcycle range, plopped it into a sports coupe, and called it a day. You could get a version of this engine in the squarer, more conventional N360 coupe, where period road tests noted its 116 km/h (72 mph) top speed.
The swoopy Z is probably a few ticks faster.
These days, its performance statistics are pretty comical in isolation, but when compared to the top engines of the era, Honda's engineering talent shines through. How many horsepower made per litre of engine displacement is a great way to judge an engine, and the little Z in its top trim made an incredible 101 horsepower per litre—and it wasn't even the sportiest model Honda was making at the time.
Until I get around to other classic Hondas, enjoy some old brochure scans of the Z that I managed to dig up, trying not to fall in love with this sweet, small, and sporty microcar.