2 Blade or 3 Blade

[Jcazz]

Ok everyone, i am in the mix on what type of props to use with my prather 11cc tunnel with HTB pipe and header. I have used the 2 blade prather props before and they seem to work well, i have a S235 and an S240. But would the right 3 blade props work as well as the 2 blades, or will the 3 blade slow the boat down a bit more but increase handling?

 

[Jcazz]

bump~ please help me on this question, i have ran .21 tunnels in the past etc, but this is my first time getting my 11cc going, ive had it for 6 years and never got it going until now

 

[Mark Poole ModVP]

The difference in what a 3 blade prop vs a 2 blade will do to the handling of the hull has as much to do with the hull itself. Some boats like a 3 blade and some don't. My experience has been the 3 blade lifts the stern of the boat a little more. Some people swear that it makes their boat turn better. Again, depends on the hull. Don't give up on a 3 blade without making changes to engine vertical position and trim position. Sometimes a very slight change in either of those will make a prop work on a particular hull.

 

[Duck899]

Its alot of trial and error......Also can depend on your driving style, weight of hull, type of hull, hull balance, etc.....A pitched up X-646/3 will work good on that hull/engine combo. I have found a 3 blade to be faster in the corners.....you will see this when as your boat corners, it will seem to gain speed......An X-452/3 or possibly an X-455/3 may also work.....I have always gone for rpm, so smaller diameters with more pitch worked for me......Play with engine height and angles and even tilting the engine when viewed from the back to load the sponsons when cornering......Lots of testing required......tunnels can be the hardest hulls to set up.....

 

[moparbarn]

my experience on .21 tunnels is that 3's handle better/maintain more speed in the turns, and 2's may be faster in a straight line. a HUGE generalization here, but that's usually the way it works for me. i have a favorite modded x437-3 that my top speed 1 loves, and my dumas hot shot hates. i also have a modded x-440 that my ts2 loves, and the ts1 and dumas don't like as much. purely individual per boat, motor, setup and driving style. gotta go burn nitro to find out. have to experiment with every prop. two blades seem to like more nose weight, and three's can work better with less nose weight, it seems. 3's will run better higher than most 2's. 2's seem to prop walk/move the back of the boat sideways worse than 3's. 2's can have a better hole shot-more "blowout", to get rpm up quickly and unload the motor to get on the pipe faster than 3's. none of this is cold, hard facts, just what i've noticed on my boats.

 

[Jcazz]

Guys i can now see the prop that is currently on my boat, well the number that is now, its an X447/3 on a prather hull made a little bit before the lap cat 3 was introduced, 11cc with htb pipe/header, is this prop to small for this setup or should i try either my prather 235 or 240 props,.or will the following props above be a better choice to start with, i know setup and boat has ALOT to do, just need some direction, thanks agian for the help everyone !!

 

[Jcazz]

bump!