Performance of the Durajet vs. Conventional Propeller
The DuraJet was developed to eliminate propeller injury and provide an accident free alternative to the conventional propeller. To date, over 2 million hours of use by the USMC, First Response Rescue Units and recreational boaters have proven to be accident free using pump jet propulsion.
An accurate test of the advantages of the DuraJet would be to have an object come into contact with the pump jet running at 1500 rpm and then do the same with a propeller. The comparison would be graphic, definitive and dangerous.
When we talk to recreational boaters, they readily admit the safety advantages of the DuraJet. Then they want to talk about performance of the DuraJet compared to a propeller. We tested the DuraJet against a conventional propeller driven Evinrude Etec 50 HP outboard on a 20 ft Starcraft Pontoon with a loaded weight of 1,785 pounds (4 passengers, 6 gal fuel). The propeller used was a standard 13.5 x 11 aluminum 3 blade.
Speeds were measured using both a radar gun and GPS to ensure accuracy. At all RPM levels the DuraJet produced virtually the same speeds and fuel consumption as the conventional propeller.
Older traditional outboard jets lose 20-30% of their power because of water feeding chutes and water directional changes. They require larger motors resulting in added fuel cost.
A conventional propeller produces thrust in a conical shape emanating from the center of the rotational radius. The DuraJet produces a column of thrust in straight lines from the jet. This enables more responsive handling and tighter turns than a propeller.
The DuraJet was designed to use 100% of rated engine horsepower. Unlike impeller pumps, the DuraJet draws water in the front and thrusts it out the back. The water is accelerated in the direction of travel with no loss of power due to ducting or vectoring.
Unlike a propeller the water exiting the jet is not allowed to spread out or twist.
All of the force of thrust is directed out of the nozzle in one direction. Because the thrust is concentrated out of the nozzle it provides a greater forward force. This enables a boat to come on plane faster and improves steering at high and low speeds.
In avoidance turns the propeller will ingest air resulting in “blow out” with a loss of power. This is less likely to happen with the DuraJet.
The forward looking housing design of the DuraJet collects water being feed into the entrance providing a more efficient and consistent hook up.
The DuraJet reverses more like a car by pulling the back of the boat in the direction the jet is pointed.
The DuraJet housing is smaller than a propeller. It also protects the rotor/drive train from rocks and other submersed objects, that in many cases would destroy an open propeller.
A motor equipped with a DuraJet, rather than a propeller, is less likely to fail because of drive train damage after striking immovable objects.
DuraJet is designed to eliminate propeller injury accidents. DuraJet has a proven track record of exceptional performance using pump jet propulsion.
• Delivers virtually same speed
• Provides improved durability
• High & Low speed maneuvering, safety and handling
DuraJet and Pump Jet Propulsion
Products ~ Made in the USA