Why DOHC was used
Engines require a lot of performance. The most obvious is performance. DOHC is said to be synonymous with high-performance engines. It was a longing for car lovers. Needless to say, DOHC is the first letter of the double overhead camshaft. It was created to increase intake efficiency and exhaust efficiency and obtain high performance.
The camshaft placed on the cylinder head and the push rod eliminated by driving the belt and chain from the crankshaft is called OHC or SOHC, and the DOHC system was developed. This engine uses two camshafts to open and close intake and exhaust valves. Because there are two camshafts, it is also called "twin cam". Since the camshaft can be placed near the valve, the degree of freedom in designing the valve arrangement and the number of valves is high, and the filling efficiency is greatly improved.
で き It can be easily turned to high rotation, and it is easy to obtain high output. For this reason, many high-performance vehicles adopt the DOHC system. Honda was the first to commercialize a DOHC engine in Japan. Honda, which had participated in the two-wheeled world grand prix, adopted the DOHC system to squeeze high power in a limited displacement.
1In January 1962, Honda announced its entry into the automobile industry. Six months later, in June, the 11th National Honda Association was held at the recently completed Suzuka Circuit. At this time, Honda officials unveiled the S360 open sports car and the T360 light truck. The two prototypes had an in-line four-cylinder DOHC engine. At the ninth All Japan Auto Show in October, three vehicles, including the Honda S500, were exhibited as a reference, causing a sensation.
The first to be released is the light truck T360. It was launched in August 1963, and is the world's smallest 4-cylinder DOHC. In October, S500 was put on the market. The 531cc AS280E is the first DOHC engine in the passenger car category. Wet liners, roller bearing-supported crankshafts, direct-acting tappets, etc. are used for all aluminum blocks. Much of that mechanic is handed down to Honda's F1 engine. In January 1964, the advanced AS285E DOHC was mounted on the S600. In January 1966, the AS800E was loaded on the S800.
Honda also has a DOHC engine on the light van LM700. However, the greatness of DOHC was not understood by people at that time because it was loaded on commercial vehicles.
Nostalgic Hero vol.146 August 2011 [All contents in the article are as of the time of publication]