gene375

I have a 235 SS prather and am interested in switching to a 3 blade prop, What are the advantages and disadvantages on these, I cannot get a straight forward answer on this locally.. thanks.. my boat is a 40" prather .46 vrm with macs super quiet pipe, stock prather running gear. 20/20 fuel..

crrcboatz

My Feedback: (34)

Three blade props generally provide more lift out of the water. 2 blade props will more speed and rpms IF you do not over load the engine. Cup of each engine also effects both blades. Smaller diameter 3 blade vs larger 2blade with more cup well it just goes on and on.

Curt

Doubledog

My Feedback: (48)

I ordered a new Octura X470/3 the other day.

I normally run P275's on my boat & noticed quite a bit of torque roll in the boat as it powered out of corners.

A guy told me that the three blade would make acceleration smoother along with better handling in the corners.

We'll see & I'll do my own test & give my opinion.

fryfrog

My Feedback: (1)

i'm sure there are much better explainations else where, and its very likely that anything i say may be wrong or off... here is what i believe i know about props from reading quite a bit and from being around and using full size boats.

the most effecient prop is a 1 bladed one, but this isn't possible due to the vibration. next is a 2 bladed, then so on and so forth.

there are a couple of reasons to use 3-4 bladed props on real boats (and r/c too). on a real boat, some of the larger horsepower engines would produce to much torque with a 3 bladed prop going 75+mph, so they go with 4 blades to drasticly reduce the torque. it also artificially inflates the diameter of the prop, allowing more of the engines power to be transfered to the water.

from what i understand, you are almost always better off with a 2 bladed prop IF it works for you. if the diameter of the prop is limited, and the engine is not loaded enough the only thing you can do is increase the blades to put more of the engines power into the water. of course it can help a lot with torque, but at the cost of effeciency.

crrcboatz

My Feedback: (34)

I agree with everything the last post said AND I will add againg that the 3 blade prop will LIFT the boat out of the water more also. So if you need more lift ie, running too wet and like the strut and rudder setting you have you can try a 3 blade. Also when the water is glassy try it because the chop will naturally help with lift, without it the 3 blade will help.

Curt

Doubledog

My Feedback: (48)

Thats exactly what I'm hoping for along with a little more in the corners. However, I'm a firm believer in for a $15 part, try it for yourself. Thats what I'm doing as soon as it gets here.

I've run the full scale boats ie,, STV's, Allisons, Hydrostreams & more high performance bass boats than you can shake a stick at so I understand how two props that look almost exactly the same can have differences in speed & handling by 5+MPH. Torque steer etc...

The saying around the boating community is, "Never turn down the chance to try another prop."

[email protected]

Actually from what I've been told w/the two blade you'll actually get more speed in the straight away but less in the turn, it's the opposite for the three blade. So basically they balance out some what. I'm a three blade fan for all my Scale's and tunnels. Here is a good example, if your runninf a 3.5 tunnel and have an Octure X-437 on it and it won't lift, I wouldn't tell you to go get a three blade. I'd tell you to buy the Octura X-1437, better known as a lifting prop.
Hope this helps, sometimes it's more difficult to explain by e-mail what really works well for another boater.

Ron Olson

My Feedback: (1)

2 vs. 3 bladed props, it will depend a lot on your boat. Weight, suface or sub-surface drive, nitro content, engine, you name it. A 3-blade will have at least one blade in the water at a time, but if you have a prop walk problem, it will increase it. If you like the 3-blade, try an Octura X450/3 and increase your nitro up to 40-50%. If it is too much prop, drop down to a X447 or 448 or even an X646. You might have to spend a few bucks to find out what prop you boat likes. Some of my boats like Octura's, and others like Prathers.