1954
Gassed Up
An abundance of surplus fuel left over from the Korean Conflict is present in Japan. This means new vehicles must be tuned on 92 RON for the mass market. It seems as though the days if low grade fuel are over. The Japanese economy is looking up, people are making more money now, moving into cities and raising families. It seems as though the times of conflict for Japan are over. They can finally have a breath of fresh air and focus on growing the economy and promoting business and economical wellbeing. The increase in the economy means that people can actually afford this new type of fuel. First, all of the Hirosaki engines were tuned and adjusted for better performance and economy. First up was the H series motor. The H motor recieved two new variants. The H10 was adapted into the H10A2. This new motor was much more efficient and was much more powerful. The H8 was also modified to use the new fuel. This new variant of the H8 was called the H8A3. It was much more efficient than the previous motor and ran much smoother. The Four-Twelve was up next, recieving the least ammount of change. It was adapted to simply take the benefits of the new fuel. The tuning remained relatively unchanged. All of these new motors were given the same duel barrel carb which made a huge impact in the fuel economy of these vehicles. The new Four Twelve variant was denoted as the Four Twelve T2, after the T, the first variant.
Pictured Above: The H10A2 during its production.
Pictured Below: The H8A3 being tuned on 92RON.
Pictured Above: The Four-Twelve T2
These new motors would be available soon in new model vehicles that had the old variations of this motor.
H10A2 Specifications
Build: Cast Iron block, head, and internals. DAOHC Valvetrain. Single Carb. Tuned on 92 RON.
Horsepower: 50 hp @ 5,800RPM
Torque: 52 lb-ft @ 3,900RPM
Bore: 2.673 in
Stroke: 2.720 in
Compression: 7.2:1
H8A3 Specifications
Build: Cast Iron block, head, and internals. DAOHC Valvetrain. Single Carb. Tuned on 92 RON.
Horsepower: 39 hp @ 5800RPM
Torque: 42 lb-ft @ 3500RPM
Bore: 2.522 in
Stroke: 2.614 in
Compression: 8.0:1
Four-Twelve T2 Specifications
Build: Cast Iron block, head, and internals. DAOHC Valvetrain. Single Carb. Tuned on 92 RON.
Horsepower: 61 hp @ 5700 RPM
Torque: 64 lb-ft @ 3700 RPM
Bore: 2.681 in
Stroke: 3.236 in
Compression: 7.3:1