DETROIT, MICH., March 12, 2004
Mercury Marine turns engine technology on its ear with a new category of outboard engine using high-performance DuPont polymers in 21 key parts of its new Verado four-stroke engines. Introduced to the market Feb. 12, the engine was prominently featured in the DuPont booth #1643 at the SAE World Congress.

Verado, a vertically integrated in-line six cylinder engine, marks Mercury's entry into high-horsepower, whisper-quiet four-stroke engines. With up to 275 horsepower, the supercharged engine is one of the company's most powerful and quietest outboard ever produced. The new engine also holds a three-star emission compliance rating from the California Air Resources Board and is positioned to comply with the new Federal emission requirements due to come into effect in 2006.

Strong, silent type: Handsome new Verado four-stroke engine from Mercury Marine relies on DuPont polymers for cowling, other key components.

"We leveraged the best from automotive engine design to deliver a new category of outboard engine that is dazzling the boating industry," said Rick Davis, Mercury's chief technology officer. He credits DuPont polymers and technical support for making crucial contributions to the successful development of the Verado. "DuPont high-performance materials deliver major benefits over metals and thermosets in holding down weight and cost, combating corrosion and enabling us to set new standards for outboard engine performance and durability," he said.

"Strategic application of polymers in this engine has helped Mercury Marine derive significant benefits in the areas of improved Noise, Vibration and Harshness (NVH), with excellent quality and durability. Significant cost reductions due to elimination of paint, machining operations and reduced assembly costs have been attributed to the application of polymers," said Mitesh Sheth, polymer materials engineer for Mercury.

Engine subsystems using DuPont high-performance polymers on Verado include cowling, supercharger, fuel delivery, cam cover, air handling, powertrain and electrical/electronic controls.

"This is a truly exciting and innovative engine – not just from a performance and materials perspective, but in terms of the development," said Dino Tres, a DuPont development programs manager who coordinated the company's technical support to Mercury Marine. "Mercury honored us by inviting our contributions from a materials technology point of view and working side-by-side in executing this program over the past few years. We all benefited from the collaboration."

Cowl assembly: Big injection molded parts deliver big benefits
In the cowl assembly of Verado, six innovative parts made of DuPont high-performance polymers provide a combination of structural, protective and aesthetic functions.

The top cowl is the largest component ever injection molded from glass reinforced nylon. Made of a 33 percent glass reinforced DuPont™ Zytel® nylon, it is shaped like a giant scoop measuring 851 millimeters (33.5 inches) front to back, 582 millimeters (22.9 Inches) across and up to 417 millimeters (16.4 inches deep). It weighs just 11.3 pounds (5.13 kilogram), far less than a metal or a thermoset plastic housing.

The rear cowl, and a structural rib that is adhesive-bonded to it, are molded from the same Zytel® resin. The front cowl is molded from DuPont™ Minlon® mineral/glass reinforced nylon for added flatness. The lower cowling, or chaps, consists of two mating parts molded from DuPont™ Surlyn® Reflection Series® ionomer alloys for superior gloss without paint.

These components meet several demanding requirements and deliver major benefits over alternative materials. For example, they:

• Mate precisely to prevent water from entering the engine compartment.
• Provide improved NVH Verado is the quietest and lowest vibration engine in its class.
• Provide excellent structural strength and impact resistance.
• Resist motor fuel, oil, various cleaning agents and corrosive saltwater.
• Stand up to temperatures ranging up to 200°F in the upper cowl.
• Weigh about 30 percent less (15.2 kilogram, 33.5 pounds) than thermoset SMC (sheet molding compound) parts.
• Cost 46 percent less than SMC cowls, thanks to the integration of assembly and functional features in part designs, and due to reduced costs of painting attributed to less paint consumption, reduced surface preparation and higher first pass paint line yields.

The cowl parts made of Zytel® and Minlon® are finished in a three-coat system providing first-pass acceptance yields of 95 percent or better at each stage, according to Mercury Marine. By contrast, SMC cowling parts used for other Mercury engines require application of filler to deal with porosity, a primer and two finish coats. Adding to cost, painting yields are low, as each coat requires multiple passes to repair defects caused by porosity and solvent popping.

The lower cowl molded from DuPont™ Surlyn Reflection Series® ionomer alloy has high-gloss finish and integral color. It incurs no painting costs at all.

Smart Engine
According to Tim Reid, director of engine design for Mercury Marine, "Verado offers an integrated outboard system with uncompromised NVH, reliability, durability and performance. Features like SmartCraft® Digital Throttle and Shift (DTS), high-performance Advanced Mid-Section (AMS) with a progressive-rate outboard mounting system and Electro-Hydraulic Power Steering system make Verado a truly pioneering product in the marine industry and make this outboard best-in-class in driver interface and satisfaction. Mercury's Engine Guardian constantly monitors all vital engine functions, warning the operator of potential problems and proactively taking corrective actions to avoid engine damage. Our patented supercharger air-induction system, with a highly tuned intake resonator, reduces intake noise by up to 14 dBA in the midrange to full throttle, without sacrificing engine performance".

Supercharger boosts power of compact engine
Verado is the world's first production outboard featuring a supercharger. According to Mercury, the supercharger enables its 2.6 liter Verado engine to deliver significantly higher torque and acceleration than competitive 3.0 to 3.6 liter four-strokes. Its performance equals that of a 4.0 to 4.5 liter naturally aspirated engine, which would be far too bulky and heavy for an outboard, their engineers say.

The supercharger, a rotary Lysholm-type co-developed by Mercury and IHI Turbo America uses rotors coated with DuPont™ Teflon® fluoropolymer. "Teflon® was critical to our success," said Davis. "Other materials caused the rotors to quickly corrode and wear out."

Fuel module meets stringent requirements
Verado has an innovative electrically powered fuel delivery module located outside the engine compartment, between the engine and the propeller. The module is protected in a two-piece housing molded from DuPont™ Zytel® HTN high performance polyamide. It contains two fuel pumps, one to draw fuel into the housing from the tank and another to pump it to the fuel injection rail.

Thanks to the use of Zytel® HTN and astute part design, the housing can meet demanding requirements and deliver cost and performance benefits over metal housings.

• It stands up in nearly continuous contact with motor fuel on the inside and seawater on the outside. In certain boat application and running conditions, the fuel delivery module operates continuously immersed in saltwater.
• It costs about 15 percent less than an equivalent aluminum module and has numerous integral features that avoid the need for separate parts and/or costly machining that would be required with a metal housing. The module provides a weight reduction of 19.7 percent (0.45 kilogram or 1.0 pounds) compared to an aluminum module.

The housing's molded-in assembly features include fittings for in and out fuel lines, a manifold reference line, a groove for the rubber sealing ring, support members for the fuel pumps and a pressure regulator and mounting ears. Integrated fittings reduced the potential for leak paths and polymer materials provided excellent corrosion resistance.

Cam cover seals oil in, water out
The cam cover of the Verado is molded from DuPont™ Minlon® mineral/glass-reinforced nylon. It provides a 1.8 kilogram (4 pound) weight saving and considerable cost savings compared with an aluminum cover.

The cover draws on the material technology and design principles employed for similar nylon components used on automotive engines, but it overcomes unique oil-sealing challenges posed by the engine's vertical position and the marine environment.

The integration of functional and assembly features in the cover reduces costs by reducing part count and minimizing assembly steps. For example, an oil-air separator is molded-in. Another cost-saving feature involves separately molded breather plate, which unlike a metal part can be ultrasonically welded into the cover.

Air handling system helps keep down noise
Verado engines also deliver cost, weight and performance benefits by incorporating automotive industry learning into the design and materials employed for the air intake manifold and resonator.

The air intake manifold (photo at right) is a one-piece design that delivers a weight saving of more than 50 percent compared with aluminum, better corrosion resistance, and runners with smoother interior surfaces for improved air flow to the engine. It is molded from 33 percent glass-reinforced Zytel® nylon.

The resonator efficiently manages noise, vibration and harshness and incorporates an air filter in its design. The resonator is a two-chamber design consisting of a center tube injection molded from Zytel® 15 percent glass-reinforced nylon, and a blow molded outer body also made of Zytel®.

Powertrain components have what it takes
The powertrain of the Verado engine also includes a torsional damper made of DuPont high-performance polymers.

The torsional damper, molded from DuPont™ Vamac® ethylene acrylic elastomer, is pressed into place on the flywheel to dampen torsional harmonic movements. The damper made of Vamac® meets Mercury's demanding requirements for resistance to hot oil at temperatures ranging up to 150°C.

Electrical system
Verado comes with state-of-the-art electrical controls and systems. For protection and servicing ease, its modules are consolidated in a control box with a cover, both molded from a glass-reinforced grade of DuPont™ Crastin® PBT thermoplastic polyester.

Comprehensive technical support
"DuPont technical support played a major part in our success with polymer components," said Mitesh Sheth, the plastics engineer at Mercury Marine who led in coordinating contacts between the two companies and with the molder suppliers.

"The level of technical excellence demonstrated by the many people of DuPont throughout this entire program was truly world class," said Dr. Kevin Anderson, manager of metallurgy, chemistry, plastics and corrosion at Mercury Marine.

Depending on the need, DuPont specialists recommended suitable materials for evaluation by Mercury, provided input for initial designs (including finite element analysis in several cases), performed flow and warp analysis to aid in optimizing part and mold design and worked with molders in optimizing quality and productivity.

Aiming to add to its successes with high-performance polymers, Mercury is working with DuPont on development of a number of components for new engines in its pipeline and existing models as well.

Mercury Marine, based in Fond du Lac, Wis., is a division of Brunswick Corporation. Additional information about Verado or other Mercury Marine products is available on the website at www.mercurymarine.com or contact Steve Fleming, director of Communications, Mercury Marine, Phone: 920-929-5340.

For more information about DuPont high-performance polymers, visit plastics.dupont.com on the Web or call 1-800-441-0575.

DuPont is a science company. Founded in 1802, DuPont puts science to work by solving problems and creating solutions that make people's lives better, safer and easier. Operating in more than 70 countries, the company offers a wide range of products and services to markets including agriculture, nutrition, electronics, communications, safety and protection, home and construction, transportation and apparel.

The DuPont Oval, DuPont™, The miracles of science™, Crastin®, Minlon®, Teflon®, Zytel® and Vamac® are registered trademarks or trademarks of DuPont or its affiliates. SmartCraft® is a registered trademark of Mercury Marine.

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