3 blade prop ?

[kck741]

I want to get a new prop for my SV 27(Octura v940/3)<I was thinking about this.Anyway what is the difference betwen a 2 blade and a 3 blade prop.does a 3 blade help with cavitation???

[Fluid]

The v9xx/3 props are lifting props and do not work well on monos like the SV27. This is due to blade shape, not the number of blades. A 3-bladed prop allows a smaller diameter for less torque roll. IMO 3-bladed props are seldom a good idea for most FE boats - a 2-blade will usually do better.

If you are going from a 2-blade prop to a 3-blade prop, the rule of thumb is to get a 3-blade prop with 80% of the diameter of the 2-bladed one.


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[kck741]

OK so a 3 blade will cause the hull to lift out of the water making prop walk

[SJFE]

Ok so even though the v9xx series of props are listed for cat/mono's. They are better suited for hydros. Correct?

[kck741]

then why does the SV come with a 3 blade?Does it not have enough pitch to make it a lifter prop??I see alot of monos with a 3 blade

[Fluid]

OK so a 3 blade will cause the hull to lift out of the water making prop walk...then why does the SV come with a 3 blade?

You didn't seem to read my post very well.

...This is due to blade shape, not the number of blades....

The number of blades has nothing to do with it, it is due to the shape of the blades.


I do not know where the V9xx series is listed for cats and monos, but it is certainly not appropriate for them. I did set records with a v937/3 on a special SAW cat, but for most cats it is a very poor choice. On monos it simply does not work. For oval racing with hydros they are okay but better props exist. For SAW racing they are awesome.

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[kck741]

OK I see

[ReddyWatts]

I run a Y537/3 on a 14XL with 24 cells in a Mean Machine hull. It is my favorite prop for sport running with this setup.

[SJFE]

I do not know where the V9xx series is listed for cats and monos

I read it first in Mr Reddy Watts Prop description post.

V9 are moderate lift suitable for riggers, mono's and cat

Then I remember reading it again in this octura prop directoryLink Not that I dought what you said for a second I'm just trying to point you tward where I saw it.

[Fluid]

SJFE - I don't see the v9xx series props recommended for any boats in the link you posted...

A little history: Octura designed the v937/3 for 3.5 outboard tunnels. The prop was a failure in that application and languished for years until discovered by FE guys in about 2001.


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[SJFE]

Know what your right. I thought that was the place where I saw it. Thats what I get for rushing to find a link on the way to bed:blushing:. Maybe I just wanted justifie the two finished v9xx's in my prop box so bad I believed I saw it.

[kck741]

Fluid-thanks for pointing me in the right direction.Im going with an Octura 445 2 blade prop of course