The Development of The Rotary Engine

Trial and Challenge
Last Updated on Aug.28,1996



The photos we show here are belong to "The Rotary Graffiti 1967-1987".
All the documents are written by Kenichi Yamamoto.


It is natural to having an improvement toward it when a technique has completed, then usually it goes into maturity and moving to a period of stability.

In 1967 when Cosmo sports put on sale, which carried two rotor engines for the first time in the world, the social condition was in high-growth age at that time.
A national income was increased and there was a plan to magnify a freeway. The world is just in the middst of motorization. The rotary engine which combined high-performance with stillness have seemed went well to have the name "rotary feeling" own way.

But next the second difficulty had waited immediately for the rotary engine which had just born. In USA the exhaust gas control had began by the federal government in 1968. It was a moderate thing to attack it for the people who was reluctant to using rotary engine in practice.

They said "It'll be the problem about exhaust gas pollution after this, but it is difficult to take measures to the situation with rotary engines which have much Hydrocarbon (HC)"
or "The rotary engine with much HC will never drive in America, permanently from now."
In short, abuse and slader started to crush that rotary engines have no future.

But we have believed it is USA that have the market which have pioneer spirit and greet a new techniques in good will, or find out the merit of rotary engine indeed with advancing the motorization more. It was also a thing to stimulate in conversely for the technical experts who had conquired the trial, "impossibility of practical use" and passed through the sparks of fire, moreover, handled the engine that have to produce with confirming the origin by themselves or find out a technical skill to way out.

A conception had completed, in short, thermal reactor, a heat reaction tool that to burn HC positively to make use of its characteristic which have much HC but little NOx. It is an idea to burn HC, the gasoline of the remainder after burning, completely on the way of exhaust pipe.
More steadily development have kept on to practical this thermal reactor and the development have done on material and structure side that was unprecedented before. Among those materials, there was a thing which have very superior heatproof but when we pressed to shape, it cracked into pices.
As to boast the young technical experts who had literally devoted himself entirely to succeded the pressing of this material that "I will press even if it is a glass."
Like this, we could land the rotary engine car on USA in October,1969 which was told that will not drive in America.

There was "exhaust gas pollution incident at Yanagi-cho crossing in Ushigome, Shinjuku" after this in the country and USA there was "smog pollution in Los Angeles" which was taken up by mass comunication that "Los is cring !". Voices were getting louder day by day that to strengthen the exhaust gas control.

It is too famous story that the air purity rule by a senator maskey, in short the maskey rule which is calling in the world, have approved at a federal congress on December in 1970.
It was only our rotary engine and Honda which have CVCC that declared the possibility of achievement at a seat of EPA public hearing about the application of a year postponement. I want to add that the CVCC of Honda at that time also have a reaction, so that it was very resemble thing in a sense.
Conversely after that, the rotary engine which took measures at HC, have made its predominance that consists in exhaust gas purification. Because, originally the NOx, which treatment is difficult with usual round-motion piston engine, is rare. It have became to say that "The rotary is the favorite engine of exhaust gas measure" until about 1973, this is very sarcastic story.

But the trial was still continued. It is the first energy crisis which happened at the end of 1973, rotary engines were going to rush into the third difficulty. Antipathy against rotary engines at the problem of exhaust gas control were rising up as the flame of abuse once again.
Rotary engines have charged a disgrace of gas guzzler (a car which guaff the gasoline), taking this energy crisis as opportunity. It was hard and long days for rotary engine, the five years since the energy crisis in 1974 till 1978.
This is an actual feeling that the outbreak of energy crisis was too fast, to look from the maturity of its technique on the history of developing rotary engine. Usually our development was intentioned, emphasis on drawing out natual ability of rotary engine and exhaust gas control to get quarification as the car engine.

Many encouragement letters have sent to me of course from the country but also from the foreign countries. Even the suggestion about the development of rotary engine was incruded among those letters. They gave me their experiences and suggestions which got from their actual life that spent own money to carry on unknown engine.
If we are the group of technical experts challenge unknown things, in short the pioneer, they must be the pioneer users. They are the users who had challenged a new field with us. I felt some human relation between those people who have interests and expectations to the innovation of an internal combustion engine, which have not experienced before. If we will spoil this, it will be branded that "Don't try a new things in the innovation of an internal combustion engine." We will be a precedent. We will contrary those people's expectations in the world. And it will be a break of young people's dream who have made an effort, There was a historic mission.

Caused by the first energy crisis, our environment of the management have grew worth rapidly. And it is true that there was a intense discussion about the maintain of rotary enginen among it.
Our management formation has making a decision, "Maintain of rotary engine is the social responsility of the maker and it is also the problem about fidelity to the customers who have patronize rotary engine car already. Let's give up the disgrace of gas guzzler as soon as possible."

In 1974 we formed a five year plan for the fuel expenses improvement. This plan was called "Phoenix Project". It was adopted from the name of phoenix that revives from ashes again.
All sorts of challenging forgot the profit and loss of technical experts have kept going. Indomitable spirits, the word "Rotary Spirits" was born unawares between them.




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