Honda’s Flagship BF250 Engine

Innovative four stroke engine is Honda’s most powerful and now its flagship entry in the crowded outboard propulsion markets.

The new BF250 horsepower (hp) four-stroke engine, the most powerful outboard ever to join the Honda Marine lineup, is also the company’s flagship model. Incorporating a number of advanced technological innovations that contribute to the engine’s high fuel economy and superior performance, the 3.6-liter engine is additionally equipped with an all-new gear case, the world’s first marine direct air dual circuit induction system of its type (providing for cooler, denser air for better combustion than conventional under-cowl induction systems) and has a full-throttle rpm range of 5,300-6,300.

The Honda BF250 marine outboard engine incorporates a host of Honda-exclusive technologies that provide increased value and benefit to consumers and workboat customers alike. Satisfying their primary pleasure and consumer market audience first, the styling concept of the new Honda BF250 incorporates a sleeker and slimmer aesthetic design. Included in this configuration are technologically advanced features that Honda portrays as the engine’s “best-in-class” fuel economy, power and charging performance. According to Alan Simmons, national manager at Honda Marine, “The introduction of this flagship engine also further strengthens our relationship with both consumers and boat-builder partners.”

Dual Purpose Market Penetration
Steve Drenkard, assistant manager, marketing, Honda Marine, wouldn’t discuss specific sales data but he told MarineNews in April that since its October 2011 introduction, “The BF250 had sold well and has been a great new power option for customers globally.” And, although Honda is perhaps best known for its marine products in the pleasure niche, the B250 is robust enough to stand the test of a commercial operation. Drenkard added, “The BF250 is most certainly versatile for both commercial and recreational applications, and we have enjoyed success in both segments with the new outboard.  We do have a strong history of providing our outboards for military applications such as the U.S. Coast Guard’s Homeland Security initiative, so we will continue to maintain our relationships within the market. That being said, Honda Marine strongly values our recreational customer and always works to provide the best boating experience we can to those customers – through low cost of ownership, great performance and ease of operation.” Arguably, those three metrics transcend all lines of business.

Honda outboards have long been shown to be a good fit for military and law enforcement applications with years of proven service. Many government agencies choose Honda Marine products for their low operational costs and long term reliability, helping keep budgets in line. The latest BF250, for example, is seeing service on new and repowered military and law enforcement patrol boats. Because of that, the B250 must satisfy a myriad of requirements across a wide range of applications, said Drenkard. “Just like all Honda products, our outboards are built to last. Commercial operators are extremely tough on their equipment and view their outboards as work tools. In relation, reliability and low operational costs often are most important to these users. If their outboard is out of service, they’re losing money.”
 
VTEC and BLAST: Honda’s B250 One-Two Punch
VTEC, or Variable Valve Timing and Lift Electronic Control, is a Honda engine exclusive, used in both Honda Marine engine and Honda Automotive engine applications. First debuted in the high-performance Acura NSX sports car, VTEC provides power when needed by providing a broader, flatter torque curve and smooth power delivery throughout the engine’s operating range. This is achieved by using mild cam lobes to operate intake valves at low rpm, then engaging a high-output lobe for higher rpm operation. The result is a great combination of power, torque and fuel economy. VTEC gives the captain the benefit of a larger displacement engine by providing excellent mid-range punch while providing fuel economy figures of a smaller displacement engine at cruising and trolling speeds.  Drenkard added, “With VTEC, commercial operators get the best of both worlds.”

BLAST, or Boosted Low Speed Torque, uses a unique Honda spark advance system to provide more horsepower when it is needed most. When the throttle is advanced quickly, BLAST activates to open up the throttle body, change the air-fuel ratio to a richer setting and aggressively advance the ignition timing. According to Honda, this allows the engine to produce more torque to improve acceleration (hole shot) at low speeds. For law enforcement, military and patrol operations, the combination of VTEC and BLAST, therefore, represents an enormous advantage.

Hand in Hand: Fuel Economy and the Environment
All Honda outboards boast environmental performance that includes meeting the rigorous California CARB Three-Star Standard. The Three-Star label identifies engines as Ultra Low Emission if they meet CARB’s 2008 exhaust emission standards. Engines meeting this standard produce 65 percent fewer emissions than One Star (Low Emission) engines. Along with that – and just as important – the new Honda Marine BF250 outboard engine produces enviable best fuel economy.

According to Steve Drenkard, Lean Burn Control is the key. Automatically adjusting the air/fuel mix according to speed and load while maximizing power throughout the acceleration range – providing as much as 20 percent greater fuel economy in cruise mode (2,000 to 4,500 rpm) – Lean Burn Control has been enhanced to improve fuel efficiency even further in specific cruising ranges, resulting in best-in-class fuel economy – as much as 30 percent better than competitive models, depending on specific running conditions. The air/fuel ratio control is performed by the Electronic Control Unit (ECU), based on the feedback from the O2 sensor, allowing more accurate control in the lean-burn range. Finally, the gear case of the BF250 engine incorporates an advanced design that minimizes water resistance, and by extension, reduces the overall drag coefficient by five percent (even without the use of the larger, optional propeller).

Standardizing Outboard Deliveries: Easing the Repower Decision   
Because the BF250 engine mounts on industry-standard 26” centers, repowering twin BF250s is convenient. Having a 26” industry-standard engine mount is an advantage in several ways. In terms of repowering, older boats traditionally utilized the standard 26” distance, making it an easy fit to repower with Honda engines that utilize the same standard. By extension, having to modify a transom to accommodate a different distance is costly. Having ample room between the two outboards allows for easier access for maintenance, and this distance provides tighter turning capability.

The Modern Outboard: Not Just for Fun Anymore
Honda Marine, a division of American Honda Motor Co., Inc., markets a complete range of outboard marine engines. Its entire product line is powered exclusively by four-stroke engines designed for high fuel efficiency, quiet operation and low emissions. With a full-throttle rpm range of 5,300-6,300, the Honda BF250 is a high-performance 3.6-leter engine that incorporates an all-new gear case and advancements from Honda’s automotive and marine outboard engine lines. Honda’s Steve Drenkard declined to discuss the next big move for Honda Marine, but in terms of its commercial sector plans, he said, “We can’t discuss future product plans, but we can confirm we will continue to refine our products and develop new ones to meet the unique needs of the workboat operator.”

If the B250 engine is any indication of what is to come next, then Honda’s role as a force in the workboat markets is anything but at full throttle. And, that’s because this engine manufacturer, known best as a pleasure market product provider, has arrived on the commercial and military waterfronts. Indeed, it has been there all along.

(As published in the May 2013 edition of Marine News - www.marinelink.com)