Curbside Classic: Honda Civic – The CVCC In The Words Of Honda Engineers

Slowdown can be a time for reflection. As the Japanese economy cooled by the 90’s and recession took grip, industry and populace were left to wonder, what happened? Where did it go wrong? And how did it go right in the first place?

In the early 2000s, after years of economic stagnation, NHK TV Japan started a documentary series looking back on the country’s economic rise after WWII. The show, Project X: Challengers, placed special emphasis on the innovative spirit that propelled postwar Japanese prosperity. The series has Japanese broadcast quality, with report-like interviews interspersed with period footage and less than convincing recreations; and a female voice seductively whispering in Japanese-accented-English the show’s title randomly: “Project X.”

Emperor Puyi in Manchukuo, wondering where it all went wrong in “The Last Emperor.”


The show made it to Latin America with special attention paid to El Salvador, as Japan’s ambassador went on air in local TV to introduce episode 1. There’s actually a longstanding friendship between the two nations, dating back to the tumultuous 1930s. El Salvador’s military dictatorship was one of 3 nations that recognized the Japanese puppet state of Manchukuo in mainland China (A reference to this appears on Bertolucci’s The Last Emperor). It’s also rumored that Japanese subs docked in Salvadorian waters during those eventful years; impossible to prove, but fascinating nonetheless.

Japan’s rising vehicle parc in the 1960’s. From Tatra87.


Honda’s CVCC tech is part of Project X’s season 1 (the Spanish broadcast is online, in glorious low-res VHS quality). The show brought forth Honda engineers experiences on the CVCC’s development, adding some human interest to what’s been shared previously on those events. Not surprisingly, corporate speak places a bit more emphasis on Soichiro Honda’s inspirational role as company president, while engineers emphasized their own actions. Regardless, even without Mr. Honda’s direct engineering involvement, CVCC tech wouldn’t have existed without the culture of innovation he imbedded in his working force.

But first off, what’s CVCC?

It stands for Compound Vortex Controlled Combustion engine (If the initialism is a bit obscure, that’s by design. Stay tuned). At launch, it was an industry game changer, both in technical terms and as a marketing triumph. With CVCC, Honda became the first carmaker to comply with provisions stated in the US Clean Air Act of 1970, even fulfilling the 1975 threshold where all passenger cars were to reduce emissions 90% versus 1970 levels. Honda’s feat established the carmaker as a force to reckon with, and left Detroit’s big 3 looking like spoiled bickering kids.


So, how does CVCC work?

While most automakers were aiming to meet regulation goals with not-quite-well-developed injection systems and catalytic converters, Honda went for a different approach by leaning out the intake mixture. Easier said than done, as too lean a mix would eventually not allow combustion to occur, and that’s where CVCC came in. Honda developed a miniature extra combustion chamber in the engine’s head, and by feeding a rich fuel-air mixture into this tiny pre-combustion chamber, the leaner mix in the primary chamber could be ignited.

The lean mixture in the cylinder head allowed the CVCC engine to run smoothly, while reducing CO and hydrocarbon emissions, even lowering fuel consumption some. Also, Honda’s engine could run on leaded fuel, while competing makers would leave customers scrambling for the appropriate fuel pump.


And how was CVCC developed?

I’ll divert here a bit. During John Coltrane’s heyday in the 60’s, envious fellow musicians asked Coltrane’s sessions ensemble: “How do you play like that?” Coltrane’s rhythms seemed out of this world, and the techniques required were just beyond most players grasp. The ensemble’s reply to the question? A very serious: “Well… you’ve to be willing to die with the motherf…..r!”

In similar manner, to work with Soichiro Honda was to be “… willing to die with the man!” (I just can’t refer to Mr. Honda with an expletive).

Honda’s origin was rather different than that of established players like Nissan or Mitsubishi, both created by Japan’s wealthy elites. Instead, humble Honda started first as a bike shop, then as piston ring provider for Toyota. By the late 50’s, the company was riding a wave of success with their motorcycle line. Soichiro Honda, the mercurial and impetuous company founder, had driven the company’s rise on  reliability, speed, and outside the box thinking.

Soichiro Honda’s life had started as a humble son of a bike repair shop owner. Fascinated by the automobile since an early age, Honda left home at 16 to pursue a mechanic apprenticeship and, with endless inexhaustible drive, finessed his engineering sense (lacking formal training, at times it was more instinct than engineering). Mr. Honda was a force of nature, with all photos showing a determined individual ready to take over the world. Timidity was something that didn’t run in his blood, with boundless enthusiasm and optimism being key to his legendary driven character.

In 1937, Honda’s ascendance started by becoming a Toyota supplier, and carefully surrounding himself with key managers. These individuals adhered to Soichiro’s interest in developing innovative technology with products that stood out. To play outside boundaries was a company philosophy from its inception.

As the company grew, Soichiro remained a mechanic in spirit, preferring to spend his daytime hours in the workshops and assembly lines rather than meeting rooms. A quality he retained until old age. Spending much time side by side, company employees referred affectionately to Mr. Honda as papa, probably in the full spirit of the times; a figure that inspired both admiration and fear.

Football legend Pelé taking a ride with an extrovert Mr. Honda.


Soichiro’s fervor didn’t come with downsides though, for he reacted quite passionately against those who didn’t share his vision or enthusiasm. Punches and heated arguments were notorious traits of his, as more than one employee observed. Must have been soft punches, for everyone resumed work immediately (and let’s not judge Mr. Honda by current sensibilities, please). On the plus side, Soichiro wasn’t known for holding a grudge; those who were in the receiving end of his punches and anger, were amiably saluted the day after as if nothing had ever happened.

The Honda team at the Isle of Man TT, with a casual Mike Hailwood.


Papa had pushed the company hard since day one, and by the early ’60s it was bearing fruit. In 1961 alone, at the Isle of Man TT, Honda’s bike racing team arrived in the first five positions of both, 175cc and 250cc categories. Feat accomplished, the company took sights onto the 500cc category, accumulating more victories. Biking world taken over, Soichiro was now onto his next quest, car making and F-1 racing.

By the early ’60s, Japan’s individual prosperity had risen and car ownership was becoming the norm, with the 1000cc category being where market action laid. Work on Honda’s N360 started, with the goal to bring some unseen performance to the segment. By then, the company had a workforce of 400 young engineers who had nothing but admiration for the company’s products and its founder. In company speak, their engineers “Loved work more than a good meal.” Which was quite something to say, as Japanese food is quite good.

Coinciding with Japan’s and Honda’s rising fortunes, environmental concerns were becoming a worldwide issue. Low slung smog had become a norm in metropolitan areas around the world, and in the US, congress took action with the 1963 Clean Air Act. Shizuo Yagi, head of Honda’s Engine Performance Research Block, read in international press of the passing of the Clean Air Act and how emissions controls were to become a factor in coming years.

Yagi developed an interest in the news, as it could be a groundbreaking area for the company. He knew that Mr. Honda “…enjoyed arriving first than anyone else to everything.” The engineer was also anticipating Japan’s raising concerns, which was facing its own issues with pollution and industrial accidents since the ’50s (The nation would institute its own pollution controls starting in 1966).

Yagi had already endured more than one heated argument with Mr. Honda as employee. A memorable one, missing out on his honeymoon while benchtesting and failing an engine test. As a piston piece flew off barely missing his forehead: “…papa started to punch away…I just let him rage away, if I tried to duck him, he would have gotten angrier.” (This time I’ll give some reason to Soichiro, exploding pistons are not good for business).

Still, Yagi felt confident enough to take the matter to Soichiro and asked for “…a chance to research emissions.” Mr. Honda shrugged shoulders, answering with a non-enthusiastic “Sure, er…go ahead.” Regardless of Honda’s dim response, in 1965, Mr. Yagi was allocated a team of 10 engineers to peruse the matter. It became known as the AP (Air Pollution) Study.

As the N360 was launched and became a sales success, Yagi’s team was left to their own, looked upon with some scorn by company employees. Honda had become a cool company, and speed was its defining quality; taking samples from tailpipes wasn’t exactly winning any hearts for Yagi’s AP Study.

Still, in 1966 Yagi and team visited US emission research labs thanks to efforts arranged by Japan’s Auto Manufacturers Asociation. On return, the team was expanded to 28 members, with some key players joining. Even at this early stage, the AP Study team settled on developing a clean engine as the project’s goal.

By 1968 the company was growing rapidly, putting most resources towards development of the Life and the 1300 vehicles. The new vehicles still focused on speed and unorthodox engineering, Soichiro’s specialty. Meanwhile, work progressed slowly at the AP Study, as emissions research was lightyears away from the members’ former training. Early challenges; how to measure emissions? And how to understand those measurements?

From early on, Yagi was convinced that to lessen pollution fuel intake had to be reduced. On this the team bucked an industry trend, since most manufacturers preferred post-combustion processing devices such as catalytic converters (a technology the team distrusted for still being too crude). Thus, in perfect Honda fashion, the AP Study tackled the matter in a roundabout way.

Soichiro didn’t shun the teams efforts completely, for he was a devoted father, even if his kids appeared to had gone astray. He popped in and out, bringing in suggestions AP Study members often found to be “…pie in the sky.” Still, his presence brought necessary momentum when the team came to a standstill, with his frequent remmark: “You can’t learn until you try.”

That said, the AP Study was quickly reaching nowhere, with endless failures in testing. So, while the company had entertained the idea, with a pressing need for resources towards new models and in-development water cooled engines, AP Study salaries were slashed and members reallocated elsewhere.

1970 was a definitive year. AP Study member Isao Fuji got a cue on their ‘how to reduce fuel’ quandary in a Russian engineering textbook (If anyone knew of fuel shortages, it would be those Russians under the Communist boot). The textbook told of early research done in gasoline engines adapting diesel combustion prechambers. With that in mind, an early test was conducted on a N600 engine, and emissions were greatly reduced. It ran incredibly poor though; much would have to be done to get it ready for mass production.

Rather than wait for the team to sort out a proper gasoline engine for testing, Soichiro brought his impatient self in action, suggesting to use Honda’s available diesels. The team complied. “Just when we were about to give our plan its finishing touches,” engineer Otami recalls, “Mr. Honda would give us new instructions. It always meant we’d have to redo it all from scratch.”

In 1970, Honda’s negligent homicide accusation made rounds in the news.


Two main events were to set the CVCC’s project fate. In July 18, 1970, 43 students passed out during gym class in a Tokyo high school. The culprit? Photochemical reactions produced by vehicle emissions from a jammed highway. The event placed the increasing concerns of rising pollution in the public’s eye.

Weeks later, Soichiro Honda was accused of negligent homicide; a young man had died at the wheel of a N360, with the grieving family blaming the motorcycle manufacturer directly. Consumer groups joined in, placing in their crossfire those pesky ‘kei’ car makers that built ‘defective vehicles.’ The cue rang true to a public already weary of industrial mishaps (mercury river poisoning, along a few others industrial disasters, were very recent in the collective mind).

Iacocca tells Congress “Nope, can’t do!”


In the US, the updated 1970 Clean Air Act became law, requiring emissions to be reduced progressively and drastically, with the biggest hurdle being a 90% reduction by 1975.

With N360’s sales slowing down and the recently launched 1350 not meeting sales expectations, Honda found itself suddenly ailing, even considering dropping their passenger vehicle line altogether. With the AP Study lying around their labs, management took a sudden shine to it as a possible lifeline.

In February 1971, Soichiro announced that Honda was developing a new low emissions engine, and that it would comply with the US Clean Air Act of 1970. It was a shocking claim by the rookie carmaker, as Detroit’s PR was spewing how the task was insurmountable for any carmaker, bemoaning the fact in Congress hearings. Meanwhile the EPA took Honda’s word, offering to test the engine whenever they felt ready to do so.

(At announcement, Honda referred to the new tech as Compound Vortex Controlled Combustion, CVCC. The term was intentionally vague, as it was still in development and patents were not secured. Honda’s PR found a nice sounding hi-tech term that kept competition out of the loop of the system’s inner workings).

Before the February pronouncement, Mr. Honda had called head engineer Yagi to forewarn him: “The company’s future rests on that engine’s success.” Pressure, anyone? A coyly smiling Yagi reminisced: “As always, Mr. Honda would tell us to climb to the roof…and then pull the ladder from beneath you…that’s just the way he was.”

The AP Study now being a company priority, resources were largely reallocated. Tadashi Kume, one of Soichiro’s favorite engineers (on lieu of speaking his mind and butting heads constantly) was placed in charge. Kume assigned only young engineers to the AP Study, keeping Soichiro out of the loop; probably sensing the engine’s work required a new approach, and that Soichiro’s looming shadow tended to inhibit impressionable team members.

AP Study heads started to convene at a downtown hotel –intentionally away from headquarters- to set the project’s goals and methods. Itemizing the issues to solve, the plan was peppered with military terms. Baptized as Landing in Iojima, the team’s structure was as thus: Mr. Kume was general commander, Mr. Yagi, air support (in charge of patents), and Engineer Akira, landing commander (engine development and subsequent US approval).

Back at headquarters, Kume announced to company employees that within a 9-month deadline, Honda was to be the first carmaker that would comply with the US 1970 Clean Air Act. Engineer Minoru Atsumi recalled: “(At the announcement) panic ensued on the team. But up until then, we had had so many absurd demands, that one more… If it were a game of golf, it would be like scoring a hole over undulating terrain.” As engine tester, Atsumi was to spend many nights away from home.

CVCC development was in full countdown by March 1972, with 400 engineers assigned. On the to-do-list, over 1000 engineering items to solve. More than 100 engine prototypes were built. When prototypes failed, “no engineer was allowed to go home until the problem was solved.” Bunker beds were placed around the company grounds. This being Japan, a corny (us, cynical westerners) motivating motto was chosen: “Save the blue sky.”

Sometime during that year, a rift ensued between Soichiro Honda and his faithful employees. At motivational company meetings, Soichiro’s language had changed, constantly referring to the project as “Honda’s opportunity.” Yagi and engineer Toshimasa Shishido reflected negatively on this “… in the past, papa would tell us we were working for ourselves, for society…” An angry Shishido took this complain to management “You can’t let papa say those kinds of things!”

The comment was brought forth to papa by corporate heads, and between his advancing age, and the CVCC work going ahead without his direct input, a number of thoughts must have been spinning around his restless head.

A Nissan Sunny ready for a CVCC? From the cohort by Hannes.


By October 1972, the AP Study-CVCC engine was ready and testing in track, with pollution astoundingly reduced. Notice how we’re talking about the CVCC engine being tested, as the Civic itself was still on the drawing board (or clay sculpting). In need to expedite CVCC technology, and with no car at Honda large enough to take in the new water cooled engine, Nissan Sunnys were fitted for testing. (Here Project X shows a Civic heroically in track testing, which is the magic of television).

General Commander Kume proceeded with Landing in Iojima, and along key players of the AP Study, arrived to Ann Arbor, USA, in December 5, 1972. On the 7th, the engine was at the EPA testing labs, only to fail miserably. A loud gurgling noise appeared as soon as the car started, running roughly, and with emissions shot to the upper registers. EPA’s Eric Stork, with perfect American empathy, tried to soothe the wounded pride of the Asian newcomers “better luck next time.” Commander Kume didn’t give up though, asking if they could check their wounded-in-combat ailing engine. On quick inspection, the team assessed that damage to the carburetor had occurred in shipping. Would it be possible to fix the engine and test again the next day? Having no line of manufacturers in wait, EPA’s Stork complied amiably.

Too psyched from the test’s failure, Commander Kume spent the evening hours consuming heavy liqueurs in hopes to find some sleep (can you blame him?). No rest came to him however, only drunken stupor. No comments on how he found his way back to the EPA the next morning, but that day the CVCC engine finally passed EPA testing with flying colors. Upstart Honda had leapfrogged a good number of established makes to the finish line, and the news helped cement the company’s ascendancy as an innovative force in the industry. Honda was now a purveyor of technology, with Chrysler and Ford interested, and Toyota becoming a CVCC client.

(Kume’s recollection seems to differ by one day from what’s posted at Honda’s web regarding approval date).

“Pelé and Honda… Perfect Team.”


Regulations tend to drive the ire of not only carmakers, but a segment of the car loving public as well. “Would have…” “Could have…” counterfactual scenarios are impossible to assess, and can go on endlessly if the mind wonders. Corny Japanese motivational mottos aside, nowadays the morning Salvadorian sky is blue in ways it wasn’t back in the 80’s. And that, with a car population much expanded since then. For this I’m greatly grateful.

No local regulations are to thank for my blue skies, though. Instead, it’s thanks to modern low-emission vehicles that make up most local traffic. CVCC tech has been much surpased since its launch, but the fruit of such efforts are an indelible legacy.

Whatever thoughts the CVCC development had on papa, we’ll never quite know. But two months before the Civic’s CVCC launch, Soichiro quit the company’s presidency, while expressing: “…the pupil has grown up. In this case, it’s ok to leave the company in their hands.”

The Civic was aimed from the start as an international car.


With Soichiro Honda falling in the company’s background, engineer Minoru Atsumi reminisced on those days: “The CVCC project must have been a bitter pill for Mr. Honda. The company’s employees loved him…he worked really hard, and always checked on us. In some ways, he was actually more like a father to me than my own had been…”

All this said with a timid smile. The kind of smile that comes from hardship; mixing a bit of nostalgia, the joy of challenges overcomed, and nervousness at the pain endured.

A Civic CVCC still running in San Salvador, 2022.


(Note: Attributed quotes are, in general, rough translations from Spanish and Google Translator).

More on the CVCC:
Automotive History: Soichiro Honda Spanks GM CEO

More on the Civic:

Vintage Review 1975 Honda Civic CVCC

CC 1973-79 Honda The Second Little Revolutionary

CC 1978 Honda Civic Wagon, 2 Speed Hondamatic