Honda's New V8 BF350, Biggest Outboard Engine To Date
Taking a closer look at Honda's new contender in the world of V8 outboard engine power plants: the BF350.
October 19, 2023
Honda Marine recently unveiled the new Honda 350-HP V8 outboard engine, joining the esteemed company of Mercury Marine, Yamaha Outboards, and Suzuki Marine, all of whom had previously crossed the 300 horsepower threshold. This engine made its first appearance at the International Boatbuilders Exhibition and Conference (IBEX) in Tampa, FL, earlier this month. Let's take a look at this power plant in more detail.
Above: Honda BF350 V8 Outboard Engine. Photo by Honda Marine.
First 300+ HP Engine From Honda
There's much to delve into about this impressive engine. For starters, the BF350 is Honda's inaugural foray into producing a V-8 outboard. One of the notable features of the BF350 is its fuel efficiency—while several 350 hp engines necessitate 91 octane, this engine efficiently operates on just 86 octane, providing a more economical option for owners at fuel stations.
Above: Honda BF350 V8 Outboard Engine. Photo by Honda Marine.
Overall Specs
Diving further into the engine's specifics: The BF350's powerhead adopts a single overhead cam configuration with a 60-degree angle, coupled with a 32-valve V-8. It boasts a displacement of 302 cubic inches. Performance-wise, the engine peaks at 350 hp at 5500 rpm, with an operational rpm spectrum ranging from 5000 to 6000. The bore and stroke dimensions stand at 3.5" and 3.9" respectively, with a 10:1 compression ratio. Its gear reduction is set at 1.79:1. In terms of weight, it's 765 pounds for the 25” shaft variant and 776 pounds for the 30” version. The alternator is robust, churning out a total of 93 amps, with 70 amps dedicated to power generation.
Honda's AMP+ System
A remarkable feature is the "AMP+" system by Honda. During idle states, if the engine detects a demand for more amperage, it will autonomously raise its rpm by 100, enhancing the output by nine amps. This ingenious mechanism ensures that the batteries aren't inadvertently depleted when there's a surge in accessory usage during prolonged low-rpm operations.
Additional Key Features
1. High-Tech Integrations
The BF350 is equipped with state-of-the-art features like cruise control, available in 50 rpm increments from 650 to 6000 rpm, and a trolling mode that ranges from 650 to 1000 rpm. Its drive-by-wire controls integrate seamlessly with Honda’s Intelligent Shift and Throttle.
2. Compatibility
The BF350 showcases its versatility with plug-and-play integration capabilities with Dometic’s Optimus 360 joystick boat control system, which can manage up to four engines. Additionally, it's fully compatible with most Multi-Function Display (MFD) systems through NMEA2000 engine data compatibility.
Performance Enhancements
1. Fuel Efficiency
Thanks to its Lean Burn Control and multiport programmed fuel injection, Honda alleges that the BF350 holds a 17-percent edge over its competitors in terms of cruising fuel economy.
2. Design Insights
The engine employs a fully balanced 30-degree offset crankshaft, eliminating the need for counterbalancing and merging perfectly with the 60-degree engine layout. Notably, this approach mirrors that of the Acura NSX sportscar, hinting at Honda's application of their automotive prowess in the marine arena.
3. Friction Reduction
Honda's "Friction Reduction Technology" stands out, featuring plateau honing on the engine’s cylinder bores and ion plating on the piston rings, ensuring longevity and optimal performance.
Design and Aesthetics
The BF350 is housed in a compact frame (25.6” width) and showcases a contemporary cowl design. Potential buyers have the option of choosing between Aquamarine silver and Grand Prix white, complemented by chrome emblems and sleek black trim. For enhanced convenience, the cowl design incorporates a striker guide for easy installation and handles on its sides and top for effortless removal.
Noise and Vibration
Although our team hasn't yet had any on-the-water experience with the BF350, Honda's track record suggests a potential reduction in noise and vibration compared to other outboard engines in its class. Historical models from Honda have set precedents for being exceptionally quiet and low-vibration.
Warranty and Support
Honda expresses significant confidence in the BF350 by offering a generous five-year non-declining factory warranty.
Availability and Pricing
While the exact pricing and release date for the BF350 remain undetermined, enthusiasts can expect more details to emerge in early 2024. For those eager to learn more in the interim, a visit to Honda Marine would be beneficial.
