The S600: Honda's Ingenious Roadster

The following article comes to us via King customer Andy Thompson - thanks Andy for this deep dive into a Honda classic!

****

Honda S600 Coupe

Honda has historically produced some of the most intriguing small sporty cars: the CR-X, Beat, and City Turbo to name a few. I’d like to take a step back and look at the car that started the trend, the Honda S600. I have grown a great appreciation for this car and will focus on some of the closer details that make this car so special.

Honda S600 Trifold Brochure

In a time where British and Italian companies such as MG, Triumph and Fiat were the primary producers of roadsters, Honda dared to enter the competition with almost no history in automotive design besides the Honda T360. Although the first actual car produced by Honda was the S360 -- unveiled on June 5th, 1962 -- it was never actually put into production due to lack of power. The S500 followed very shortly after in 1963 as a full production model. Although these preceded the S600, I will focus specifically on the S600 -- produced between 1964 and 1966 -- as it was the first majorly successful automobile by Honda.

Chassis

Honda S600 Chassis Cutaway

Roadsters of the 1960s were completely different vehicles than what we know of as a car today. The S600 consisted of a lightweight steel unibody with almost no safety features. Vehicles of this time hardly ever used plastic body panels. This roadster’s delicate chrome bumpers wrapped tightly around the chassis. The slightly arched rear quarter panels offered just enough contour, without disrupting a functional shape. This design style was found on other roadsters of the time and is quite pronounced in the popular Triumph Spitfire.

The S600 was not designed to be the fastest car of the time, but instead to offer the joy of driving in what has been called a motorcycle in car form. The convertible top offered the option to enjoy the world around the driver. The small body was similar to other roadsters of the time, such as the MG Midget. This popular style pushed the focus of automotive travel towards driving and experiencing the car, rather than just getting to a destination.

The S600 was offered as a traditional roadster as well as a “coupe” in standard and SM trim levels. Having various body styling and trim options is somewhat expected in today’s age -- but in the 60s, it was quite rare!

The concept of converting a performance-oriented roadster into a hard top fast back variant gave birth to a styling design that can today be referred to as a shooting brake. Shooting brakes are an uncommon but intriguing body style, as they add a sort of unbalanced complexity to the rear region of an otherwise streamline styled roadster. With this they bring a sort of exotic shape which offers better aerodynamics and generally allows the manufacture to extrude the quarter panels out far past the rear quarter windows.

Shooting brake cars never took the spotlight as only 1,800 S600 coupes were produced as compared to 11,284 convertibles. Similar sales trends can be seen between the Triumph Spitfire and its coupe counterpart the GT6. Honda didn’t pay any less attention to the coupe, as it offered the “SM” trim line to both body styles.

Honda S600 Coupe

Engine

Honda engines are known for their efficiency through such small displacement. The S600’s 606cc engine was no exception. The engine consisted of a DOHC, all aluminum, water-cooled, quad Keihin carb, inline four producing 57 hp. Almost 100 HP per liter! This sounds quite familiar to what Honda has become known to produce, and was quite an accomplishment for 1964 as other competing cars were using much larger displacement engines such as the 1.8 liter found in the MG B and the 2.1 liter engine found in the Triumph TR4.

It goes without saying that for Honda to produce enough horsepower out of an engine one-third the size of its competition, it had to rev. In this case, the magic number was 8500 rpm. Which continued to a redline of 9500 rpm.

In order to keep the hood low, the engine was designed to sit in the bay at an extreme slant. I have included a diagram of the similar S800 engine to show how pronounced this slant is. This slant is similar to that of a four cylinder motorcycle.

Honda S800 Engine Diagram

Drivetrain

The drivetrain may very well be my favorite part of this little car. Like other roadsters of the time, the S600 consisted of a front engine, rear wheel drive platform equipped with a four-speed transmission. In order to achieve power to the wheels out of such a small engine, they chose to use a 6.42:1 final drive -- extremely short gearing. Short enough to cause complaints of seeing 7000 rpm cruising at 70 mph on the freeway and causing quite a bit of noise. Keep in mind this car was originally designed for the tight city streets of Japan.

In the 60s, many automotive manufactures were tinkering with ways to offer independent rear suspension in their performance vehicles instead of a traditional solid rear axle. At the time, the constant velocity joints found in modern axles were very uncommon.

Honda had a solution. Instead of placing the rear transfer case in parallel with the rear wheels. They set it forward in line with the hinge point of the rear trailing arms. The driveshaft would turn into the transfer case and two straight shafts exited the case on either side. A chain drive system connected the exit shafts to the rear wheels. Thus allowing for a fully independent suspension with no constant velocity joints. This system is very similar to how a motorcycle transfers power to the rear wheel, but applied to a car. I have always thought this to be an amazing adaption of design and quite ingenious for the time. This mechanical genius makes the S chassis unique to the rest.

Honda S600 Drivetrain

Complimenting the fully independent suspension was a very modern spring-on-strut shock absorber system. The rear shock were mounted at a drastic angle, moving the suspension lower and yielding more trunk space.

Honda S600 Suspension

The S600 is a beautiful little machine that really shows that exotic ideas can be incorporated into an intriguing package. Although it is said that Honda never turned a profit off their early sports cars, they set a foundation of what is expected out of a small, sporty Japanese sports car: Light weight, proper handling, and a flexible high revving engine. The original S Chassis truly is a machine of another time.

Honda S600 S500 Ad