IJSF: Time-Traveled to 1901, Changing History with 21st Century Tech

Chapter 28 - Engine Development

A brief retrospective to April 1919.

"Lieutenant Miyake, these are the blueprints for the small general-purpose engine. The details about materials for the piston rings and bearings are as thorough as possible. Please collaborate with Lieutenant Yonekura regarding the materials and focus on mass production of these engines."

Miyake was tasked with the mass production of small general-purpose engines concurrently with the establishment of the Space Force Academy's technical officer course.

At this time, Japan's engine development was in its infancy, with factories barely managing to produce general-purpose gas engines. In March 1919, an engine manufacturing company in Osaka had created a prototype truck at the army's request, but it had not been adopted. The production of domestically made automobile engines was still a distant goal.

Sōryū Takashiro had prepared three types of blueprints, all designed according to 21st-century ISO standards:

1. Air-cooled, single-cylinder, 4-stroke OHV small gasoline engine. Ranging from 200cc to 350cc with almost identical design. Used for general-purpose pumps and agricultural machinery.

2. Air-cooled, single-cylinder, 4-stroke OHC small gasoline engine. Ranging from 50cc to 125cc with almost identical design, integrated with a 3-speed transmission. Used for small motorcycles.

3. Air-cooled, single-cylinder, 2-stroke engine. Ranging from 25cc to 40cc with almost identical design. Used for weed cutters and outboard motors.

Takashiro prioritized improving engine technology. More powerful engines would enable the development of higher-performance vehicles and aircraft. For instance, the engine of the Japanese Army's Type 97 medium tank developed in 1937 was a 21,7L engine producing about 150 horsepower. In contrast, the engine of the 90-type tank developed by the Self-Defense Forces in 1990 produced 1.500 horsepower from a 21,5L displacement. Despite having nearly the same displacement, the power output was ten times greater.

A powerful engine would allow for thicker armor, enhancing survivability, and the ability to mount more powerful weapons, leading to numerous advantages. Enhancing engine performance was a top priority.

However, in 1919, Japan's industrial technology was in its early stages, and there were no companies capable of outsourcing parts manufacturing. Therefore, Miyake decided to produce all prototypes within the Space Force.

Fortunately, 60 students from industrial high schools across the country were recruited into the Space Force Academy's technical officer course. They had skills in using milling machines and lathes, and some had learned welding and casting. These students were divided into teams and assigned to manufacture parts. At the same time, students from the comprehensive course, who had enrolled from rural areas, were trained in the use of machine tools. Despite being called a comprehensive course, the Space Force Academy was effectively a vocational training school. For mass production, manufacturing processes needed to be simplified to the utmost, allowing even female students to produce parts after short-term training. Until the machine tools were installed in the Space Force's armory, prototypes were made using the machinery of the Tokyo Technical School. By summer, all necessary machine tools were in place in the armory, improving work efficiency.

Miyake focused particularly on information exchange between teams. In Japan at the time, technical skills were regarded as the craftsmen's treasure, and learning such skills required apprenticeship. Miyake completely eradicated this outdated practice by holding weekly information exchange meetings. Points were awarded to teams presenting better improvement ideas or information, and every two months, the best-performing team received an "Excellence Award" from the Regent.

They devoted themselves to development, forgetting to eat or sleep, all in hopes of receiving an award from the Regent. For common young men of this era, being directly honored by the Regent was a dream come true. If they returned to their village with such an award, the entire village would undoubtedly hold a grand celebration. It would be a true moment of bringing honor to their hometown.

"If I get an award from the Regent, I'll go back to the village and marry Chiyo-chan."

With such hopeful declarations, they all threw themselves into their work. For parts requiring special alloys, such as piston rings and bearings, they collaborated with Yonekura. While Sōryū Takashiro knew the types of elements needed for making piston rings and bearings, he lacked detailed knowledge about the specific proportions and firing temperatures. Through repeated trial and error, they achieved the required strength and toughness. They also worked on improving the durability of the rubber used in oil seals. The ignition system employed the simplest method, the magneto ignition, which could be manufactured without any issues even in that era.

The first prototype was completed in December 1919.

The completed engine was a "200cc air-cooled single-cylinder 4-stroke OHV small gasoline engine."

They closed the choke and pulled the starter rope vigorously.

Brrron! Brrrrr.........

"It's working! We did it!"

"We'll mass-produce this engine, and then..."

They hugged each other in joy. For the technological level of the time, this was top-tier performance.

The engine produced 5,6 horsepower at 3.300 RPM from a 200-cc displacement and passed a 100-hour continuous operation test.

*Note: The 1920 Harley Davidson Model W produced 8 horsepower from 584 cc.

The design, based on 21st-century engine pump technology, also considered ease of mass production. Additionally, it was designed to operate reliably even with the low-quality oil and gasoline available at the time.

They immediately began preparations for mass production. The manufacturing process was broken down into detailed steps to efficiently produce parts. Students enrolled in the comprehensive course of the Space Force Academy were trained to work on the production lines. The education was handled by male technical officers. Many of the comprehensive course students were girls from rural areas sent to reduce the number of mouths to feed at home, and they quickly formed relationships with the male technical officers, leading to a series of marriages. Among the girls, marrying a technical officer became a goal.

"Well, it's great that they're finding happiness, but we won't allow early retirements for marriage. We're setting up daycare centers, so even if they have children, they'll continue working. The Space Force is equally tough on both men and women."

Initially, production was confined to within the Space Force, but technology was gradually transferred to external cooperating factories to enhance Japan's industrial capabilities. By June 1920, monthly production reached 1.000 units, and by June 1921, it had grown to 30.000 units per month, with exports extending not only within Japan but also to the United States and Europe. This also helped alleviate unemployment during the "Post-War Depression" that occurred around this period.

"Is it safe to export those high-performance engines? Won't it accelerate foreign technology and lead to the early development of nuclear weapons?"

"Probably not. I understand your concern, Liliel, but the basic technology of internal combustion engines has seen little progress for over 100 years since around 1920. Control technologies and materials have advanced, but the basic structure remains the same. Besides, engines with performance similar to this one were already in practical use in America by Harley Davidson. Ours are just cheaper and more reliable."

Production of agricultural machinery using this general-purpose engine also progressed. Additionally, the development of small motorcycle engines and two-stroke engines proceeded smoothly.