4 blade versus 3 blade propellers

Jim Hendricks Sport Fishing. 4 blades in my opinion are now usually only required on extreme applications.

Prop pitch select for minimum 5500 rpms WOT max load aboard or 5900 rpms WOT light load.

4 blade versus 3 blade propellers. Three Blade vs Four Blade Propellers and Acceleration A four-blade propeller will usually have a smaller diameter from the same pitch size as the 3 blade equivalent which is one of the reasons that they spin up more quickly than the 3 blade counterparts typically providing better acceleration. The difference between a 3-blade prop vs a 4-blade prop is that the 3-blade smaller blade ratio is faster with a higher top speed and the 4-blade higher blade ratio has a better hole-shot acceleration and better stern lift as well as better handling and fuel economy because it will keep you on plane at a lower speed. The short answer is the 4 blade propeller has more surface area and bite which allows a boat to get up on a plane and maintain it easier at a lower RPM.

However the 3 blade prop has less surface area which offers less drag and more top speed than the 4 blade prop. Three-blade props offer a nice compromise when it comes acceleration efficiency lift and speed. A four-blade propeller on the other hand can boost acceleration efficiency or lift but at the cost of a lower top speed.

Jim Hendricks Sport Fishing. Most of the time when you decrease 3-blade prop slip by at least 10 you can improve top end speed. So the 4 th blade can provide increased water displacement capability lift and grip as compared to the comparable 3-blade propeller.

In terms of actual boat performance the 4-blade can enhance handling hole shot low-speed planning ability cruise. Mk 1A had 1030 hp Merlin III driving a two bladed wooden propeller. The propeller was later replaced with a three bladed propeller with variable pitch which increased the performance.

Mk 9 had a 1720 hp Merlin 66 driving a four blade propeller. Mk 24 had a 2120 hp Griffon 85 driving a five blade propeller. In general the 3-blade propeller will have a smaller diameter than the 2-blade propeller that it replaces which also serves to reduce the tip speed and noise.

In a twin-engine aircraft the reduced diameter of the 3-blade propeller will result in less tip-generated noise and a greater clearance between the blade tip and the fuselage. One of the best places to start is with your propeller. Jon tries three different Mercury propellers on an outbo.

Looking for more performance from your boat. Cant really add much to the above excellent advice other than that there are 3 blades out there that are that good they almost border into the ability of a 4 blade without losing all the upsides of a 3 blade. The tempest plus comes to mind.

4 blades in my opinion are now usually only required on extreme applications. The 3 blade props actually have more surface area than the 4 blade prop for better holeshot and are more efficient as well so the top end is better as well. I went from a 13x13 Federal prop to a 3 blade Acme 13x115 machined prop and gained substantial holeshot and picked up more speed on the top end as wellplus a slightly softer wake to cross.

Theoretically a 3-blade propeller should always be more efficient than a 4-blade. However in the past two big issues have prevented the 3-blade from taking the lead in popularity. The first was a lack of manufacturing precision which commonly caused 3.

The 4 blade will definitely hold the water and be more responsive. Fuel mileage is usually a little better and you can usually run the motor a hole or so higher. The 3 blades I have run tend to offer more top speed seems to plane in about the same time.

To get the best of both worlds you really need to try them as much of a pain as that can be. The difference between a 3-blade prop vs a 4-blade prop is that the 3-blade smaller blade ratio is faster with a higher top speed and the 4-blade higher blade ratio has a better hole-shot acceleration and better stern lift as well as better handling and fuel economy because it will keep you on plane at a lower speed. When moving from a 3 blade 16 X 215P to a 4 blade prop WE SHOULD HAVE selected the 4 blade 1525 X 22P in the first place as the 75 reduction in diameter had a dramatic effect on WOT RPM.

At 500 and up there isnt much room for economical trial-and-error testing when you try new props in this size range. Yes the 4 and 5 blade props will get you a lower planing speed and is great for water sports like pulling a skier or wake boarder up out of the water. As you mentioned your trade off is at the higher end of the speed and RPM scale where a.

4 blades propeller a lot quicker hole shot better thrust power in crusing speed and running shallower in higher engine position. U can tow your kids sking no plm. 3 blades propeller better performance more top speed and less cupping in high engine position for shallow water.

Efficiency is still king with the 3 blades especially if long runs are made but 3 blades require a lot of specialized work when taken out of the box to bring them to life. The 4 blades are a little more forgiving even in stock form but in reality all props. Or their OFS series in 3 or 4 blade.

Give them a call probably have propped your boat model in the past. Prop pitch select for minimum 5500 rpms WOT max load aboard or 5900 rpms WOT light load. Leaves more top end power went you have to hammer down in the rough big ones to hold on backside or climb over top.

Well Ive been slowly lurking around looking at the main 2 options once the decision to switch. As of right now Im looking between the 4 blade MT and the 3 blade. Pros of the 4 blade.

• Looks cool - Ill end up with a useful load of 1155lbs - More rearward CG at 4406 in - Shorter takeoff and La.