Series engines Wind They are well-deservedly considered legends of domestic boating sports and fishing, but their potential is often left untapped due to an incorrectly selected propeller. motor-engine It's not even known that a simple propeller replacement can do wonders, adding a few kilometers per hour to a boat or significantly reducing fuel consumption. Wind 8It is often designed for average conditions and does not take into account the specifics of your boat or the desired mode of movement.
In order for the motor to operate in the optimal speed range, you need to understand the physics of the process. The propeller It converts engine torque into traction, and any changes in its geometry directly affect acceleration speed and dynamics, and an error in the choice of step or diameter can lead to overloading of the crankshaft or, conversely, to the operation of the engine at unacceptably high speeds, which can lead to serious breakdowns.
In this article, we will discuss in detail all the nuances of the selection of screws for the 8-horsepower model. You will learn how the material of the blade affects performance, why an aluminum screw can be better than a steel one in certain conditions and how to correctly measure the revolutions for the perfect setting.
Geometry and specifications: step and diameter
The main parameters that determine the behavior of a boat on the water are the diameter and pitch of the screw. Wind 8 The normal diameter is most often 225 mm, but the step can vary. Screw pitch This is the theoretical distance that a boat will travel in one full propeller revolution in a solid medium. The larger the pitch, the higher the potential maximum speed, but lower the thrust at launch and at full load.
If you install a screw with too much pitch, the engine will not be able to develop the necessary revolutions under load, which will lead to work in a "suffocated" mode, when crankshaft It's going to have tremendous vibrational loads, and it's going to get loaded with a rich mixture, and vice versa, if you put a small-step propeller in, you can spin the engine easily, but you're going to hit the so-called "ceiling" of the revs without getting the speed you want.
⚠️ Note: Operation of the engine with a screw, which does not allow it to reach the working range of revolutions (4500-5000 rpm for Winds 8), leads to accelerated wear of the piston group and overheating.
The optimal solution for a standard inflatable boat or light boat is often the installation of a propeller with a pitch of 210-220 mm. This allows you to maintain good traction when going to plane, while ensuring a decent cruising speed.
Manufacturing materials: aluminum, plastic or steel
The choice of blade material is always a compromise between price, weight and strength. Wind 8 standardize aluminum screwsThey're lightweight, they're cheap, and most importantly, when they hit an underwater obstacle, they deform, absorbing the impact energy and saving the dievect and gearbox from breaking down. Aluminum is easy to repair, although it loses some of its aerodynamic properties after recovery.
Plastic screws are becoming increasingly popular because of their ability to fold when impacted, ideal for rocky shallow waters or algae-covered waters. However, plastic has its limitations: it is less efficient at high speeds because of the flexibility of the blades and may not provide maximum traction for heavy loads, often called “anti-cavitation” or life-saving propellers.
Steel screws are for tuning motors and professionals, they're heavier, which reduces maximum speed, but their geometry remains unchanged for years. Steel allows you to create screws with thin but strong blades that have high efficiency. gearboxIt can lead to expensive repairs. Wind 8 It only makes sense if you are confident in the purity of the reservoir and want to squeeze the maximum speed.
How to find a screw for a specific boat
The rotor selection is a personal process, depending on the type of hull, displacement and number of passengers. For light PVC inflatable boats up to 3.2 meters long, the regular propeller is usually ideal. However, if you have switched to a heavier aluminum Kazanka or plan to ride with a full load (3 people + equipment), the standard step may not be enough to enter plane.
In such cases, experienced water-engines resort to a reduction in pitch, which will allow the motor to unwind more easily and pull heavy loads. There is a rule of thumb: a decrease in pitch by 1 inch (2.54 cm) adds about 200-300 revolutions to the engine. Wind 8 This is a critical parameter, as the power reserve is limited.
When buying a used screw, be sure to inspect the hub for the production of slits. The luft screw on the shaft will lead to a beating and rapid destruction of the ossels.
Also worth considering is the state of the dievekt: If the anti-cavitation plate is damaged or bent, the efficiency of any, even the most expensive screw, will fall. Water will be sucked into the area of the rarefaction, causing cavitation and loss of traction. Before replacing the screw, make sure that the geometry of the dievekt is not disturbed.
Instructions for replacement and maintenance of the propeller
Procedure for rotor replacement Wind 8 It's simple, but it requires certain safety and sequence rules, and if you don't fit it properly, it can cause the propeller to jam or, worse, to go off at full speed, and always run on a shut-down engine with the fuel hose disconnected.
You'll need a face head (usually 22 or 24 mm), a collar, and perhaps a shaft fixing stop. If the screw is stiff or rusted, don't use excessive force right away -- use penetrating lubricant. WD-40 And give it time to act, and if you hit the blades with a hammer, it can warp them or damage the bearings of the deidvect.
☑️ Replacement of the Winds 8 screw
Special attention should be paid to the nut threading on most outboard motors, including the WindIt means you have to unscrew the nut clockwise and twist it against, and if you get the wrong direction, you run the risk of breaking the thread or not being able to tighten the nut properly.
Diagnosing problems through the state of the screw
The appearance of the propeller can tell us a lot about the condition of the motor and its operating conditions, and if you notice that aluminum blades are covered with multiple small holes and shells, this is a sign of active cavitation. Cavitation It occurs when the water pressure falls below the vapor pressure, and the resulting bubbles collapse with great force, eating away the metal.
The uneven wear of the blade edges may indicate a skewed or worn bearing, and if one edge is sharp and the other is rounded, the screw is working in a skewed stream of water, which not only reduces efficiency, but also creates vibration that is transmitted to the boat's transom and tires the driver.
| A symptom. | Possible cause | Decision |
|---|---|---|
| The engine "does not pull", low revs | Too big a screw pitch | Replacement with a smaller pitch screw |
| The engine is roaring, but the speed is low. | Small step or slipping of the hub | Increase step or replace the sleeve |
| High-speed vibration | Deformation of the blades or shaft beat | Paddle editing or balancing |
| Sinks on the edges | Cavitation (often due to damage to Daydvect) | Daydvekt repair, screw polishing |
What is a hub slip?
It's a condition where the rubber sleeve inside the propeller hub wears out, the motor gains momentum, it hums, but the boat doesn't accelerate because the rotational energy isn't transferred to the propeller completely, and it's treated by replacing the hub or the whole propeller.
Tuning and improving specifications
For those who want to get out of the old Wind At the very least, there's the concept of sharpening the screw, which is the process of polishing the front and back edges of the blades to a mirror shine and giving them an optimal profile, a smooth surface reduces water resistance, and a sharp edge ("knife") cuts the water flow more efficiently, reducing the likelihood of cavitation.
However, it is worth remembering that sharpening The procedure is responsible. If you remove the excess metal, you can break the balance, which will lead to a beat, and if you have too sharp edge on the aluminum screw, it will quickly become blunt when you first contact the sand, and if you want to round the edge with a radius of about 0.5 mm, you can simulate the factory profile of the racing screws.
Another tuning method is to install screws with sickle blades, which have an increased area at the top, which allows you to better capture water when working in a semi-submersible state or on a wave. Wind 8, which is often put on light boats, it can give a noticeable increase in thrust at the start.
⚠️ Warning: When polishing the screw, don't use sandpaper with large grains. Deep scratches will become centers of cavitation and cause the metal to collapse rapidly. Use polishing pastes.
Sharpening and polishing the screw is the cheapest way to increase the efficiency of the motor without interfering with its internal device.
Remember to balance. After any machining or blade editing, it's advisable to balance the propellers out. You can do this at home by placing the propeller on two parallel blades or special cones. The heavy blade will tend downwards. Removing the metal from the heavy blade (on the back of the root) will achieve balance.
Frequently Asked Questions (FAQ)
What is the maximum diameter of the screw can be put on the Wind 8?
The standard diameter is 225 mm. Increase in diameter is not recommended, as the dievekt and anti-cavitation plate are designed for this size. Installation of a screw with a diameter of 230-235 mm can lead to air sucking and cavitation, as the flow of water around the dievekt will be disrupted. Maximum allowable increase of 5 mm is considered to be provided that the ideal state of the dievekt.
Why is it licking the splints on the screw hub?
The main reason is bumps or gassing, the rubber hub is designed to slip when it hits, to protect the gearbox, and over time, the rubber blubs or wears out, and the torque is transferred to the slits, licking them together, and it can also be a weak tightening of the mounting nut.
Can I use a screw from Winds 12 on Winds 8?
Formally, the landing shaft is the same (cone 1:10, slits), but the screws differ in pitch and diameter. The 12-horsepower version has a larger pitch (usually 230-240 mm). Installation of such a screw on an 8-horsepower engine will result in the engine not being able to develop working speeds, will work with overload and quickly fail. Use only screws with increments up to 220 mm.
How often do I need to change the screw?
The screw itself has no shelf life, but it needs to be replaced when there are permanent deformities, cracks or strong production of the hub. Aluminum screws, when actively used on rocky rivers, may require editing or replacement once a season. Plastic screws change as the blades wear out or the petals break down.
Does the material of the screw affect fuel consumption?
Yes, it does indirectly. A well-fitted propeller (regardless of the material) allows the engine to operate in optimal combustion mode. If the propeller is not selected correctly (too big a step), the engine runs on an enriched mixture with low efficiency, which dramatically increases the flow rate. Steel propellers often have more accurate geometry, which can improve efficiency slightly compared to cheap cast aluminum counterparts.