(first posted 8/16/2014) The Honda S600 is a small and sporty roadster that outwardly does not look too different from an Austin Healey Sprite or Triumph Spitfire. It is, however, much more unusual and innovative under the skin. Perhaps this is not so surprising when you consider the company it came from was one of the most interesting and unconventional (at the time). Its leader, Soichiro Honda, was arguably the most successful among unconventional automotive engineers and leaders.
Our story starts with Soichiro Honda, who was born in 1906 to a blacksmith father. As a young boy he was intrigued by the bicycles and other machines that entered his father’s shop. He quickly developed a lifelong fascination with anything mechanical, which, despite having only an early grade school education, led to an apprenticeship at an automotive repair shop. Before long, Soichiro had his own shop and at the same time seriously dabbled in race cars. He both built and drove his own race cars before a near death accident forced him from the driver’s seat.
Once peacetime returned to Japan at the conclusion of World War II, Soichiro Honda looked to build vehicles that would increase personal mobility. He took advantage of a supply of surplus wartime engines by mating them with existing bicycle designs to create a quick and easy motorcycle. It was not long before motorcycles of his own design were available. By 1954 Honda became the leading motorcycle manufacturer in Japan. Amazingly Honda snagged the top spot globally by 1959. Not bad for someone with only a rudimentary formal education!
Honda’s first dabble into the automotive market started with a prototype called the X170. Lacking a proper body, it featured an overhead cam V4 engine of 360cc capacity. In the early 1960s, the Japanese government was mulling over a scheme to divide the automotive business into niches for the strongest of the established players. This drove smaller Mazda to investigate the rotary engine as a way to set its self apart. Honda felt they had to get into the four-wheeled vehicle market before this legislation took hold. The plan never materialized, but it certainly sped Honda’s development process and the first four-wheeler was unveiled in 1962.
In stark contrast with its Japanese automotive peers, Honda started with a blank slate approach to its first car. Others had licensed or been heavily inspired by European or American design for their early vehicles, with the most obvious example being Datsun and their license-built Austin designs. As a result, these cars were extremely conventional and broke no new ground stylistically. The first Hondas, on the other hand, were a radical departure from these often frumpy designs and used technology borrowed heavily from motorcycle design.
The S500 roadster was powered by an aluminum four-cylinder engine that featured one carburetor per cylinder, dual overhead camshafts, needle-roller bearings and a 9,500-rpm redline. Most other Japanese engines of the era still followed the British pattern of a long stroke, iron block fed by fed a single carburetor. Adding a second carburetor was generally reserved for the sporty models.
Honda’s double over head cam jewel is an amazing contrast considering that some global manufacturers like Rambler still offered flathead engines. Two engine displacements were initially planned, with a 354cc 33hp engine to be offered in Japan and a 492cc engine for export markets. The smaller engine was dropped for the roadster after it was refused Kei certification, and power considerations meant the larger engine was bumped up to 531cc and 44hp.
The smaller 354cc engine did not go to waste but instead was installed in the equally radical T360 Kei class pickup truck.
The styling of the S roadsters was done in-house but was undoubtedly heavily influenced by the small European sports cars of the day. Not surprising since Soichiro Honda owned a hardtop Lotus Elite at the time. The Austin Healey Sprite and particularly the Innocenti Spyder variant are the most obvious inspirations. Even so, the Honda is no mere copy and stands up quite well as an uncommonly clean and attractive design.
The rear suspension was perhaps even more novel than the advanced engine. Rather than pinching a rear axle from a saloon donor and raising the spring rates for a sporty roadster variant, the S500 had an ingenious take on independent rear suspension. It consisted of a straight axle connected by sealed roller chains to independently sprung wheels at the rear. As well as providing independent movement of each wheel, it does away with camber changes that can cause issues with other independent designs.
This restoration in progress shows the imaginative rear suspension.
The S500 was generally only sold in right-hand drive for the Japanese market, although a handful of left-hand drive examples were built. A short time later in 1964, the S500 was replaced by the larger engined, but very similar looking, S600 roadster. Now boasting 606cc and 57hp at 8,500 rpm, the S600 was much more export friendly and can be considered Honda’s first truly mass-produced car. Honda desperately wanted to sell the S600 in the United States market where it had great success in motorcycles. They tested some roadsters in San Francisco where the hilly terrain proved too challenging for the rev happy but weak on torque engine. The S600 was sold in Canada as well as some European countries.
The S600 was available as either a drop top roadster with an optional removable hardtop or fixed roof coupe. The drop top weighed in at a feather weight 1,576lbs and the coupe, 1,609lbs.
Unlike other small sports cars of the period, there was no donor saloon car so all the switch gear, trim and lighting is unique to the S-cars, making a restoration a major undertaking.
Total S600 production from 1964 to 1966 amounted to 13,084 units divided up between 11,284 convertibles and 1,800 coupes.
The gearbox is a four-speed unit synchronized on the top three gears only. Front suspension was handled by a-arms, tube shocks and torsion bars, while lovely looking aluminum finned drums at all four corners took on braking duties.
The S800 slowly took over from the S600 during the 1966 model year. Like the name implies, it saw a displacement increase to 791cc. The increased power (now rated at 70hp) allowed Honda to claim 100mph capability for the first time. Subtle styling tweaks like a resigned grill were also included. Again available as a roadster or coupe, the first examples retained the S600’s novel rear suspension. This was soon phased out for a rather more conventional four-link, Panhard rod, live rear axle design. A short time later, front disc brakes replaced the drums at the front.
The final refinement of the original S sports cars came in 1968 with the S800M. It was well equipped with dual circuit brakes, safety glass, a factory radio, an uprated heater, and flush-mounted interior door handles. Other changes like side markers were added with the intention of selling on the US market, but this plan never came to fruition. The total of all S800 models amounted to 11,536 units when production ended in 1970. The overall production of all S500, S600 and S800 models came to almost 25,000. It would take until the year 2000 for Honda to produce another rear wheel drive roadster with a high revving, high technology engine. No chains in the suspension this time.
It would take until the year 2000 for Honda to produce another rear wheel drive roadster with a high revving, high technology engine.
I think you are forgetting about the Beat:
Were any LHD Beats ever made? I would love to import one when they get old enough to be DOT exempt.
I don’t think so, but that’s one car I could happily learn to drive from the other side!
I did neglect the Beat but it doesn’t really have an advanced engine. I even wrote about the Beat here a couple years back as we get to see some in Canada.
That’s quite a clever independent rear suspension set-up. Besides complexity and cost, I wonder what other negatives might be (maybe durability?). Probably absorbs a lot of engine torque, as well, rather than transmitting it to the pavement.
I also wonder how a Honda ‘retro-mobile’ of this sort might sell. If they could, somehow, keep costs down, probably pretty damn well.
Honda also came up with a novel approach for the subsequent 1300 sedan. It was sort of analogous to the Ford Twin I-Beam front suspension as it was basically a pair of giant swing arms, each almost the full width of the body (the right wheel’s arm was pivoted on the left side and vice versa) and suspended on a half-elliptical leaf spring.
The problem was that neither the 1300 nor the S sports cars sold well at all and it really took the more conventional Civic to make Honda a lasting success in the automotive business.
Chains are very efficient; quite low losses. These appear to be trailing arms, which means no camber change. But that has pros and cons; a bit of camber change is good, as it allows the rear wheel to have a better contact patch as the car leans in the corner.
But would chains have been able to tolerate the torque of a larger, more powerful engine? Were chains ever used in this manner on any other vehicles? I suppose it would have been possible to simply increase the size of the chains with a bigger engine, but I can’t imagine the chain gears lasting longer than the pinion gears of a differential. Half-shafts sure seem like a much simpler, better way to go for an IRS.
The whole chain thing to drive the rear wheels of a sports car really seems to be an outgrowth of a motorcycle mindset. Still a fascinating set-up, though.
Lots of early cars had chain drive, but I think you’re probably right that it would be too cumbersome and frail for any type of modern, high torque engine. Plus, it’d have to be so much longer, too – it’s probably only about 4′ from the transmission output on an S500 to its rear axle.
Well, one example in which a chain was used – and not exactly in the same manner as described here – is the two-inch-wide “Hy-Vo” chain that first appeared in the 1966 Toronado, which handled 475 lb-ft (gross) of torque produced by the engine. Aaron Severson has a good description and some incredible photos on his site, Ate Up With Motor.
I mention this not as a direct comparison, but as an observation that a properly-sized chain within a drivetrain can indeed be durable, and not contribute to immense power losses.
Great find on the Olds Toronado ‘Hy-Vo’ chain. Here’s some more info from the referenced website:
“The engineers at Morse initially told Olds that a chain strong enough to withstand the big engine’s power and torque would have to be at least 6 inches (152 mm) wide, but Andy Watt reviewed their calculations and found that they had greatly overestimated how strong the chain actually needed to be. In production form, the chain was only about 2 inches (51 mm) wide, pre-stretched to eliminate the need for an idler or tensioner.”
To expand on that point, what Watt specifically found was that the Morse people were thinking of the chain in terms of a fixed industrial engine that would run at full rated power and RPM all the time. He said basically, “Look, this is a passenger car — they don’t run like that and they’re not geared like that.” He helped them work out a more realistic stress model with some reasonable allowance for overload. It helped that the Toronado and other UPP cars had torque converters, which served to cushion driveline shocks.
It seemed to work pretty well. The Toronado had some early problems, but I don’t think the chain was ever among them.
I suspect it robs a lot of space from the trunk as well
[quote]But would chains have been able to tolerate the torque of a larger, more powerful engine? Were chains ever used in this manner on any other vehicles?[/quote]
The Mack trucks that were used to build the Mt. Wilson Observatory [way back before the light pollution from Lost Angels forced the conversion to a solar observatory] & haul the 90″(iirc) lens ground at CalTech up the mountain were chain final drive. Willing to bet they had bigger engines than something that is only considered a “middleweight” motorcycle engine today, too! 😉
Just wondering – what’s the most powerful motorcycle to use a chain drive?
I think the supercharged Kawasaki H1R produces over 300 hp
Another possible negative I can think of is weight, specifically unsprung mass, but we’d have to look at the specs to be sure. And as I have said before, I’m NOT an engineer.
Unlike typical independent rear suspensions in RWD vehicles, which have halfshafts, brakes, wheel assemblies and tires coming off of the differential, this design also has the two chain assemblies, which are each filled with lubricant to provide an oil bath for the chains (at least, that’s what I read in a Hemmings article that I found with a Google search). I have no idea what they weigh, but my understanding is that more unsprung mass has a negative impact on handling.
Unsprung weight is indeed detrimental to handling and also to ride. The easiest way to think of it is that the unsprung mass is the mass that acts on the body — picture the difference between being tapped by a 3-pound hammer and a 9-pound sledge.
The complicated thing about layouts like this is figuring out what is sprung versus unsprung. With something like the track control arm of a MacPherson strut, which is connected at one end to the wheel spindle (unsprung) and at the other to the frame/subframe (sprung), only part of the arm’s mass is unsprung.
In this case, it appears — I haven’t studied it in any detail and I’m not an engineer either — that because the chain drives are transmitting the rotation of the axle (which is entirely sprung weight) to the wheels (which are unsprung and move independently), only a portion of the chain drive’s mass is actually part of the unsprung weight and that might still be less than the unsprung mass of a live axle. That would be my guess — these are the sorts of things Honda engineers would have calculated when designing the thing and I don’t think they would have put it into production if they didn’t think it would work, the law of unintended consequences notwithstanding.
I did not know about the rear suspension design. It is a very interesting concept. It brought to mind the DAF 600 with Variomatic transmission, which was probably the first production CVT transmission. It had individual belt drives for each rear wheel, but they were actually the transmission. Effectively there was a separate transmission for each wheel, so there was no need for a differential. My father was an automotive engineer and he was very intrigued by the Variomatic, even though they were not sold in Canada. I remember his explaining how they worked and why that design would not be able to handle much more torque. He was quite excited to see them when we visited Netherlands a few years later.
Though I’ve never been an import fan, I do have an admiration for Honda, they did do things differently, they were an engineers company. These little S roadsters and or a 600 coupe should hopefully find their way into my stable someday if possible.
The little 4 banger in these roadsters is a little jewel. Prices have been increasing, I remember when these were relatively unloved and unknown. They are TINY though, the pictures don’t do it justice, they are almost go-cart sized.
Incredible cars and Honda’s story is almost unbelievable. Typical automotive wisdom states that everything they attempted early on was a horrible idea and bound to fail. Too ambitious, too complex, too expensive, too different… and yet 15 years from the day they sold their first car, they were on the verge of conquering the world and changing it forever with the first Accord. To find a similar type of success, you’d have to go all the way back to the dawn of the automobile.
The only bad thing about the original S-cars is that they didn’t build that many and sent very few to the continent I live on! I used to see basketcase S800s on eBay occasionally and try to convince myself I could pull off fixing one up… but realistically, I couldn’t and that would’ve ended up a huge disaster. Now, I hold out hope that I’ll somehow just get to drive one eventually. I imagine they’re insanely fun; probably the best version of a grown up go-kart that has ever existed.
Moreover, before the Civic and Accord debuted, Honda was involved in a very public and rather ugly scandal over the N360 kei-car. There had been a couple of traffic accidents and deaths that a Tokyo police report linked to alleged defects in the cars — which had already been singled out by Japanese consume advocates in an earlier campaign against automotive defects. The families of the dead drivers actually charged Soichiro Honda (as the supervisor of the design) with homicide through willful negligence, although Tokyo public prosecutor’s office finally decided not to pursue criminal charges, saying that there wasn’t enough evidence to establish whether the accidents were actually caused by defects, driver error, or some other factor.
You can imagine the effect all that had on Honda sales, and the fact that Honda was able to rebound so strongly (and so quickly) is really pretty astounding.
Pretty remarkable engine inside, beautifully made . Build quality was beyond the British .
Saw a beat in a wrecking yard here in Oz about a year ago, Wow!!!!!!!!!
Only one i have ever seen.
Great car to feature, David. Until this article, I never figured how close it was in looks to the Innocenti. I’ve seen one in the flesh, but never heard one running close to redline. Cheers.
Two engine displacements were initially planned with a 354cc 33hp engine to be offered in Japan and a 492cc engine for export markets. The smaller engine was dropped for the roadster after it was refused Kei certification, and power considerations meant the larger engine was bumped up to 531cc and 44hp.
To a North American, every one of these three-digit figures seems like it should have a “1” in front of it. Or, better yet, a “2”. A passenger car engine of 354cc? Really? No matter how well designed, that’s just not nearly enough displacement for something with four wheels, not two. (Unless those four wheels happen to be on a tractor mower.)
Pleasantly styled body, though: a little bit Lancia, a little bit TR6. No worse than the similar stabs at sportiness being made by Toyota and Datsun at that time. And the article itself was for me an interesting intro to the early days of Honda’s carmaking ventures: amazing, really, that such a global corporate giant got the ball rolling with a peculiar, poor-selling barchetta. The phrase “From tiny acorns mighty oaks do grow” comes to mind. Also the phrase, “Ya gotta start somewhere.”
People in a lot of markets in the sixties really couldn’t afford cars with bigger engines. The under-360cc Japanese kei-car class was sort of a special case, since the size and displacement limits were politically imposed, but when these cars were new, a lot of Japanese family cars were in the 1-liter class. (When the first Corolla and Sunny came out with 1,100cc engines in 1967, it was a big deal.) Something like a Corona 1500 was a big car for the time.
Also, in the sixties and early seventies, kei cars were legally limited to a top speed of 80 km/h (50 mph), which I think was the maximum legal speed anywhere in Japan in that era.
Their kei-cars must have had the speed limiter disabled for export markets. The Honda N360 (sold as the Scamp in Australia) and Z360 could certainly exceed 80km/h, but took their time getting there. They did well to send us the 600cc versions when they became available. Honda replaced them with the water-cooled Life about 1974 IIRC, then promptly forgot about sending us keis altogether once the Civic came out. Some other kei-cars were sold here in small numbers back around 1970, but I have no experience with them.
Both the Honda N360 and the Life were faster than that — the early Life could do 120 km/h, which prompted some internal arguments about whether it was too fast. On the other hand, a lot of modern Japanese cars are capable of more than 180 km/h as well; it’s a matter of legal restriction rather than capability.
Knew a girl in Panama who drove one of these. Don’t have a clue which one. Do remember the chain drive although I understand it much better now. I would swear it was left hand drive. Don’t know if she got one of the handful of them or if my memory is faulty. I was impressed with the drive but it sort of sounded like a couple squirrels under the hood. With a couple of 90s V6/auto exceptions, almost everything Honda that I’ve ever been acquainted with has been impressive.
Thanks for this education into early Hondas. I had no idea that anyone had used chain drive in a passenger car after, say, WWI.
I read about that SF test in MT magazine many years ago. Apparently, it couldn’t pull Nob Hill, so the test engineer tried a rolling clutch dump to make it up, frying the clutch. They went back home to Japan the next day.
Yeah, my guess is that even though these cars were appealing visually and intellectually, like the early CVCC cars their durability wasn’t up to what we were accustomed to in the US.
Really was a great read, had no idea these cars were so unique. If there ever was a four wheeled motorcycle (impossible) this would be it. So advanced in design, as others mentioned if it was a little larger with maybe 1000 cc’s, could have been a awesome little machine. I wonder what kind of MPG’s these little cars could get?
Lots of transfer cases for 4wd use chains for low range. Big blocks, rock jumpers, etc. however jumping up and down attached to where the rubber meets the road, maybe not a great idea. One bad pothole and the mounts bend all to $&17.
Still, you have to appreciate the engineering.
In 1971 I saw one of these for sale in someone’s yard in Rhode Island. The sign said, “A Mr. Toad special! A 10,000 RPM screamer!”
I assume this was a reference to the Toad character in The Wind In the Willows, which I didn’t read until 20 years later.
A recent drive in a 1966 S600
A pity the 4-cylinder S360-S800 engines never found their way to the Honda N360/N600 Kei Car if such an installation was possible.
The same goes for the Honda S800 being enlarged to 1000cc+ if there was enough stretch for it to be possible or an immediate successor being powered either by the air-cooled 1300cc engine in the Honda 1300 or the water-cooled Honda E engine.
Jonny Smith & his just about completed S600 coupe restoration – excellent video.
Nice bit of history and applications of design out of the ordinary. Found my way here as I read “Brabham – the untold story” by Davis & Armont. They mention Jack Brabham was invited by Honda to test drive their 1st race car entry, the S600. My ears pricked up when they mentioned rear chain drive and 9000rpm! The motor came from their superior motor cycle design. The things that enabled ( from my limited reading and interpretation) is this meant high torque transfer thru lighter drive train with conventional differential, THEN the high revs meant chain reduction at rear wheels and independent suspension. Brilliant. True Honda.
Nice bit of history and applications of design out of the ordinary. Found my way here as I read “Brabham – the untold story” by Davis & Armont. They mention Jack Brabham was invited by Honda to test drive their 1st race car entry, the S600. My ears pricked up when they mentioned rear chain drive and 9000rpm! The motor came from their superior motor cycle design. The high rev engine enabled, rom my limited reading and interpretation, high torque transfer thru much lighter but conventional drive train including differential. The high revs was reduced (at each rear wheel) to appropriate wheel speed thru chain reduction and meant freedom of independent suspension. The chain drive reduction has less friction thus power loss than a gear arrangement. Brilliant. True Honda. The book is also a brilliant read of driver and mechanic and the many developments made, with different teams. Not to mention the extraordinary race stories and risks, all for the pure love of it.