Honda introduced the RA301E in 1968, the third year of the 3L F1 regulations. The RA301E was a water-cooled 90-degree V12 DOHC 4-valve engine with a displacement of 2993 cc and a bore x stroke of 78 x 52.2 mm, following the basic configuration of the RA273E. The crankshaft continued to be assembled with roller bearings, as in the previous year, in order to determine its performance. The RA301E, which inherited many of the basic specifications of its predecessor, could have been called the “RA273E mod” instead.

Its appearance, however, was completely different. The RA273E had a V-bank with inner exhaust and outer intake, but the RA301E had inner intake and outer exhaust as a result of research to optimize intake and exhaust efficiency.

The cylinder head area underwent a major design change, and new technology was adopted for the valve mechanism. Coil springs for the RA273E were replaced by torsion bar springs, as at the technical level of the time, torsion bar springs had more reliable valve movement at high rpm. Honda absolute confidence in this technology through its experience with the 1L straight-4 engine for F2, which had achieved 11 consecutive victories.

The upgraded RA301E was announced to have a maximum output of over 440 hp at 11,500 rpm. This figure represented a 40-horsepower increase from the eraly RA273E.

With the RA301E powering the RA301E, a newly designed, smaller and lighter chassis, the Honda F1 team aimed to win the 1968 championship, as a realistic goal.

The time was ripe for Honda. It had been five years since its first entry in an F1 racing, and its engine and chassis had evolved steadily in terms of competitiveness. Honda had two wins and other achievements, and its presence in the F1 world had become recognized. It was clear both inside and outside of Honda that the goal of winning the F1 title was achievable.

The RA301E remained the number one high-revving, high-output engine compared to the Ford Cosworth V8 and Ferrari V12, and in the 1968 season, it was powerful and fast enough to take pole position in the high-speed Italian GP.

The RA301, however, failed to win a single race. There were many races in which luck was against Honda, and the cars continued to struggle to realize their full potential. In fact, John Surtees, who raced full-season, could only finish 4 times out of 12 races. As a result, the RA301E was a racing engine that failed to reflect its high potential in its results.

In 1968, the Honda F1 Team scored only 14 points and finished 6th in the Constructors’ standings, and Surtees was 7th overall in the Drivers’ Championship, both worse than the previous season. It was a complete loss for Honda.

In November, at the end of the season, Honda announced in London, England, that it would temporarily suspend its F1 activities, as it had just started producing and selling automobiles in 1963 and needed to grow as a automaker by developing low-pollution engines to address air pollution, a social issue at the time, and judged that continuing its F1 activities would be difficult.

However, even at the end of its first F1 era, Honda maintained its strong determination to resume its F1 activities and to one day become the F1 World Champion, an aspiration that was handed down to future generations.