Honda’s First Production V8 Engine
Honda Develops its First V8 Engine for a Commercial Product
“Honda Develops its First V8 Engine for a Commercial Product.”
In a world premiere, Honda unveiled its first V8 outboard engine, the BF350, at the Genoa International Boat Show, gaining much attention.
The V8 engine was not developed for a car, but for the BF350 outboard motor. Why did Honda feel the need to develop its first commercially available V8 engine?
Global Trends in Outboard Motors
“The market for 300 horsepower plus outboard motors continues to expand, especially in North America, the largest market for outboard motors, and our competitors have already introduced 600 horsepower models to the market. Honda’s 250-horsepower BF250 is our most powerful model, and the market has been waiting for the introduction of a 350-horsepower product,” said Keita Ito, product manager of Honda’s marine business.
Honda launched the BF250 in 2011. Since then, the needs of the outboard motor market have been shifting toward higher output.
“We were almost 10 years behind our competitors in the development of high-output models, so we developed a 350-horsepower outboard motor with many attractive features as the latest entrant in the 350-horsepower category,” said Ito.
Automobile Know-How Contributed to V8 Engine Development
“From the beginning of the BF350’s V8 engine development, we asked automobile developers to help our outboard motor developers. It was a company-wide effort.” (Ito)
Ito says there were big issues unique to the BF350.
“In today’s outboard motor market, it is common to have multiple outboard motors mounted side by side. To achieve this, the outboard motors must be lined up as possible. For this reason, we reduced the V-bank angle of the V8 engine, which is generally 90 degrees for cars, to 60 degrees.” (Ito)
The 60-degree V-bank angle required extremely high precision for the crankshaft and other parts, complicating development to meet the high demands while ensuring durability and reliability.
“We were able to overcome the difficulties because we transcended the boundaries between the various divisions including the automobile developers within Honda, and worked together as an all-Honda team.” (Ito)
Latest to Market Meant More Attention to Details
The BF350 uses regular gasoline. Generally, high-output outboard motors use high-octane gasoline, but the BF350 delivers 350 horsepower on regular, so that it can be used in areas where high-octane is difficult to obtain.
“Some BF350 customers include people who use it for work, such as on fishing boats and sightseeing boats. For professional users, who travel significantly more miles than individuals, the ability to produce 350 horsepower on regular gasoline, which is less expensive than high-octane, is a big advantage of the BF350.” (Ito)
In addition, the BF350’s fuel economy and environmental performance have been improved through lean burn (lean combustion) control, and the pursuit of manufacturing technologies such as engine friction reduction.
“Fuel economy is about 15 percent better than other products in the same class, and the ability to travel longer distances one a single tank helps reduce fuel costs and travel time.” (Ito)
Another feature of the BF350’s engine is VTEC, Honda’s unique variable valve timing lifting system now commonly used in both motorcycle and automobile engines.
With the BF350, the camshafts switch to the high-cam at speeds above 5,000 rpm, and power output is boosted dramatically.
“While cruising, the BF350 makes the most of its large-displacement engine’s ample power output for quiet, fuel-efficient operation at low rpms, and when the throttle is opened, the engine strongly accelerates, producing a powerful sound. We also focused on dynamic performance so that the driver can experience the “joy of driving.” (Ito)
In addition, the development team conducted preliminary interviews with users in Japan and overseas, and incorporated the issues they learned into the development process. One example was the oil filter’s layout.
“We improved maintainability by positioning parts requiring daily maintenance in front of the engine (on the hull side). The oil filter is placed in such a way that oil does not spill out and contaminate the sea during an oil change.” (Ito).
The current trend is for high output models to be easy to handle for novicel users. In light of this, the BF350 is a user-friendly 350 hp model with a full range of support functions, including trim support that automatically adjusts the angle of the outboard motor to maintain the optimal hull position while in motion, and cruise control that enables motion at a constant speed and rpm. The 350-horsepower model is user-friendly, and offers a wide range of support functions.
Behavior Worthy of a Flagship Model
The BF350 has a strong presence worthy of being Honda’s flagship model. Regarding the design, Ito commented, “We aimed from the start to create a styling that would blend in with stylish premium cruisers with a sense of luxury, while at the same time being ecologically friendly. The black panel behind the outboard engine is a major feature, and we have also created an unprecedented sense of luxury by finishing the Honda emblem with chrome parts.”
The BF350’s design focused on “fusion of functions as marine mobility,” “unity with various types of vessels,” and “harmony with diverse natural environments.” These elements, expressed in a simple one-motion design, were highly evaluated and won the Good Design Award for 2023.
“Outboard motors in this class need to be luxurious and powerful. I think the BF350, including its design and engine feel, expresses a total sense of prestige and quality, as well as the exuberance that its superior performance brings,” Ito claimed with a sense of pride.
Information Technology Helped Small Elite Group to Develop the Flagship
At the Hosoe Outboard Motor Plant on Lake Hamana in Hamamatsu City, Shizuoka Prefecture, where the BF350 is manufactured, various types of outboard motors are produced on a single line, but the existing line could not handle the BF350, which stands over 2 meters tall. A new dedicated cell production line was introduced, in which a small number of workers are responsible for the entire assembly process.
To smoothly implement the cell production system, which requires a large number of parts to be assembled and a wide range of work to be performed by a single worker, Honda introduced a work support system that was developed under the leadership of young engineers.
For example, the system was designed to control the tightening torque of parts, which is quality-related, and if the torque displayed on the monitor is out of the specified range, the system displays “No Good” and prevents the next process from proceeding.
These new challenges in the production process also indicate the high level of enthusiasm for the producing the BF350.
Postscript
We had the opportunity to take photographs of a boat powered by the BF350 speeding along Lake Hamana, while following in our boat powered by a 150-horsepower outboard motor.
The BF350 running on the lake, leaving ripples on the lake’s surface, was indeed a beautiful sight.
The BF350 I photographed was the white model, and from behind it looked as graceful as a red-crowned crane about to take off. Even from the outside, it was clear that even though the boat was moving at a high speed, the driver was completely relaxed and composed.
As we were taking photographs, a photographer asked us to move up alongside the BF350. Out boat was powered by a 150-horsepower outboard motor, and we could not keep up. The BF350, sensing our intention, eased the throttle a little, and we were able to take photographs alongside the BF350.
The BF350 was both powerful and graceful, and unlike the impression I had when I saw it at the factory, the BF350 in action on the lake was truly lively.