Abstract

A Moto3 category that uses 4-stroke 250 cm3 engines has been established for Grand Prix motorcycle racing from 2012. Due to this new category, Honda has developed the NSF250R, which is equipped with a newly developed 4-stroke single-cylinder 249 cm3 engine. The new engine features an intake-from-front, exhaust-to-rear layout to increase charging efficiency, and a 15° rearward tilted cylinder to concentrate mass. A thinner lightweight piston and nut-less connecting rod are used to reduce weight, an offset cylinder and a closed crankcase with scavenging pump are used to reduce friction, and a midship muffler is used to concentrate mass. These and other measures realize engine performance and maneuverability suitable for a commercial racing machine in the Moto3 category, which is the gateway to road racing.

References

1. (1) Suwa, S., Kawaguchi, D., Murakami, A., Kimura, K., Tada, M.: Development of Nitrocarburized High Strength Crankshaft Through Controlling Vanadium Carbonitride Precipitation by Normalizing, SAE Paper, 2009-32-0076 / SETC2009, 20097076 (2009)
2. (2) Marui, Y., Kinoshita, T., Takahashi, K.: Development of a Titanium Material by Utilizing Off-Grade Titanium Sponge, SAE Paper, 2002-32-1816 / SETC2002, 20024309 (2002)

Author (organization or company)

• Tomio ONOSATO（Motorcycle R&D Center）
• Yoshiyuki KURAYOSHI（Motorcycle R&D Center）

Publication Information

Article of Honda R&D Technical Review Vol.24 No.2 (32 - 39)

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Citation Information