Performance Parts & Accessories
Konrad 660B Sterndrive – Serious High-Speed Marine Propulsion for Performance Vessels
The Konrad 660B Sterndrive from Konrad Marine is a commercial-grade, dual counter-rotating propeller marine outdrive renowned for exceptional speed, precision, and reliability in demanding applications. Engineered for vessels 7-15 meters (23-50 feet), it delivers top speeds up to 60 knots (70 mph) with powerful thrust and efficient handling—making it a favorite for high-performance recreational boats, extreme government patrol, military intercept, and fast work vessels.
Featuring dual counter-rotating propellers on a one-piece shaft design, the 660B provides superior hole shot, reduced torque steer, excellent low-speed control, and enhanced efficiency compared to single-prop drives. It’s built tough with heavy-duty components for hard-working, high-speed environments.
Genuine Konrad 660B Sterndrive – dual counter-rotating props for high-speed marine performance
Key Features & Benefits for Marine Use
- Dual Counter-Rotating Propellers — Opposing rotation maximizes thrust, eliminates torque steer, improves acceleration, and enhances reverse/docking control.
- High-Speed Design — Optimized for vessels seeking 50+ knots; one-piece propeller shaft and precision gearing deliver smooth, reliable power transfer.
- Commercial-Grade Durability — Robust construction with corrosion-resistant materials, suitable for saltwater and extreme conditions; known for long service life in patrol and intercept roles.
- Versatile Gear Ratios — Options like 1.31:1 (common in listings) and others to match engine RPM, vessel weight, and performance goals.
- Propeller Range — Supports 17.25″ to 20″ diameter props for tailored efficiency and speed.
Konrad 660B Sterndrive installed – proven in high-performance and patrol boat applications
Technical Specifications
| Specification | Details |
|---|---|
| Vessel Length | 7-15 m (23-50 ft) |
| Max Speed | Up to 60 knots (70 mph) |
| Propeller Design | Dual counter-rotating (one-piece shaft) |
| Propeller Diameter Range | 17.25″ to 20″ (43.8-51 cm) |
| Common Gear Ratio | 1.31:1 (others available) |
| Fluid Capacity (Complete Drive) | ~16.5 quarts (15.1 liters) |
| Applications | High-speed recreational, patrol, military intercept, fast fishing vessels |
| Duty Classification | Performance-driven / hard-working speed apps |
Advantages Table: Konrad 660B for High-Performance Boating
| Feature | Konrad 660B Benefit | Boating Advantage |
|---|---|---|
| Dual Counter-Rotating Props | Opposing rotation on one-piece shaft | Faster acceleration, no torque steer, precise control |
| High-Speed Capability | Up to 60 knots on mid-size vessels | Ideal for performance & intercept applications |
| Durability | Commercial-grade build & corrosion resistance | Long life in saltwater & demanding use |
| Thrust & Efficiency | Optimized prop range & gearing | Strong hole shot & better fuel economy at speed |
| Handling | Excellent low-speed & reverse performance | Superior docking & maneuverability |
| Reliability | Proven in government & military roles | Reduced downtime & maintenance |
Comparison Table: Konrad 660B vs MerCruiser Bravo Three Series
| Feature | Konrad 660B | MerCruiser Bravo Three (Dual Prop) |
|---|---|---|
| Prop Design | Dual counter-rotating (one-piece shaft) | Dual contra-rotating |
| Max Speed Focus | Up to 60 knots (high-performance emphasis) | Up to 65 mph (balanced performance) |
| Vessel Size | 23-50 ft (mid-size high-speed) | Broader range (cruisers to sport boats) |
| Durability | Commercial-grade for extreme/patrol use | Recreational/marine-grade with X upgrades |
| Best For | Speed-driven, patrol, military, fast fishing | Family cruisers, towing, general boating |
| Gear Ratios | Flexible (e.g., 1.31:1 common) | Multiple (1.81:1 to 2.43:1) |
| Applications | Hard-working speed & intercept | Versatile recreational/marine |
The Konrad 660B stands out for raw high-speed performance and ruggedness in specialized roles, while MerCruiser Bravo offers broader recreational versatility.
Konrad 660B in action – dual props delivering precision and speed on a performance vessel
Ideal Vessel Applications
- High-Performance Recreational Boats — Fast fishing, sport, or day cruisers.
- Government Patrol & Military Intercept — Extreme speed and reliability.
- Fast Work Vessels — Commercial or patrol boats needing quick response.
- Twin-Engine Setups — Balanced thrust for 30-50 ft hulls (e.g., twin Duramax 6.6L or similar).
- Repower Projects — Upgrade for vessels seeking superior speed over standard sterndrives.
At Hammer Engines in New York City, we stock genuine Konrad 660B sterndrives (new, remanufactured, or certified units) with expert pairing to compatible inboard engines like Duramax, Cummins, or high-output gas/diesel options. Fast global shipping, custom gear ratio and propeller recommendations, plus dedicated marine support for your high-performance project.
Shop Konrad 660B Sterndrive Now or contact our specialists for availability, pricing, or a complete marine propulsion package quote!
