Description

Sterndrive 620 Konrad Marine: The Ultimate Propulsion System for Diverse Marine Applications

Konrad Marine is a leading manufacturer of stern drive propulsion systems designed for a wide range of global marine applications. The 600 Series Stern Drive product line includes three models: KONRAD 620, KONRAD 660, and KONRAD 680, each catering to specific performance requirements.

Konrad 620: The Workhorse of the Fleet

The Konrad 620 is considered the most dependable and robust drive in the series. It combines Konrad’s proven 51cm single propeller technology with stronger shafts and gears, setting a new standard for stern drive durability. This model is built to withstand the demands of commercial, military, medium-duty, and recreational applications, ensuring reliable performance in various marine conditions.

Konrad 660: Built for High-Speed Performance

The Konrad 660 is designed for performance-driven applications, such as extreme government patrols or sports leisure boating. With dual 41cm counter-rotating propellers, the 660 is capable of powering vessels between 7 to 15 meters long, achieving speeds up to 60 knots (70 mph). This drive is engineered to deliver the speed and efficiency needed for high-performance marine operations.

Konrad 680: The Ultimate in Power and Efficiency

Engineered with the largest, strongest gears in the industry, the Konrad 680 can handle carrying capacities up to 7.7 metric tons per drive. Operating efficiently in the 46mph range, this model features dual 51cm counter-rotating propellers and is ideal for heavy-duty, commercial, and military applications where strength and efficiency are paramount.

Exclusive Harmonically Tuned Gear Train (HTGT) Technology

Each model in the 600 Series is equipped with Konrad’s exclusive Harmonically Tuned Gear Train (HTGT) technology, which optimizes the balance of the drives, reduces vibrations, and enhances the synchronization of internal components. This results in a significantly smoother running system, improving the overall performance and longevity of the drives.

Key Features of the Konrad 620 

The Konrad 620B is ideal for military, commercial, medium-duty, and recreational performance. It offers a variety of advanced features, including:

• Oversized bearings for improved durability
• Thicker-walled casings for enhanced strength
• One-piece propeller shaft for superior reliability
• Continuous oil circulation for cooler operation
• Corrosion-free exhaust design
• Precision-machined super alloy gears
• Minimal maintenance requirements

Standard Equipment Supplied with Sterndrive

• Complete sterndrive assembly
• Inner and outer transom assembly
• Digital trim display and trim pump assembly
• Oil reservoir with low-level sensor for use in hull
• Sterndrive lubricant and power trim fluid
• Transom-mounted integrated trim and steering cylinders

Additional Equipment Required

• Transmission
• Propeller
• Steering package
• Drive shafts/transmission tailpiece
• Bellhousing adapter
• Flywheel coupling
• Transmission oil cooler
• Alignment tool

Options for Individual Applications

• Dual Helm kits
• Isolator mounts
• Installation tool kit
• Extension kits
• Tie bars
• Stand-off boxes
• Technical engineering assistance

Manufacturing Specifications

• Bearings: Taper roller bearings for optimum load carrying
• Castings: High-strength, heat-treated aluminum
• Gears: High-performance alloy steel, heat-treated for strength
• Shafts: High-alloy, heat-treated steel
• U-Joint: Industry-leading size for increased load capacity and extended life

Operational Specifications

• Application: Suitable for both recreational and commercial use
• Engine Connection: Direct or Remote (Jack or CV Shaft)
• Exhaust: None through the sterndrive
• Gear Ratios: 1.27:1, 1.45:1, 1.55:1, 1.78:1, 1.98:1
• Lubrication: Full immersion with 17 quarts and external reservoir
• Propeller Diameter Range: 17.25 in – 20 in (43.8 cm – 51 cm)
• Rotation: Counter rotation
• Steering Angle: 50° range
• Transmission: Reversing transmission required
• Transom Mounting: Template available per application
• Transom Requirements: 13° nominal angle, 6.4 mm – 79.4 mm thickness
• Trim/Lift System: Approximate -6° to +10° trim, twin cylinders with electrohydraulic pump, and 30° of total lift range
• Water Pickup: None through the sterndrive

The Sterndrive 620 Konrad Marine series is engineered for exceptional performance, offering a reliable, robust, and efficient solution for a wide range of marine applications. Whether you need speed, power, or durability, Konrad Marine delivers with precision-engineered propulsion systems.