5 blade propellor

[Mrdeli]

Whilst surfing the net today i came across a firm selling a 5 blade prop. I've seen lots of 4 blades advertised, but this is the first 5 blader I've seen. Are they a gimick.... ot are there real benefits???

Thanks

MArk

example...

http://www.steeldevelopments.com/erol.html#731x750

[Petrov]

The Quicksilver high five has 5 blades.

[Petrov]

Sorry didnt check the link before.

[simmons0]

As it says on the webpage:
"Ultimate accleration for sking and towing. Extremly smoth running propeller from its 5 blade design 4.3/4" Gearcase."

Usually see them on boats that need the extra acceleration, waterskiing boats or heavy cruisers proped to get them up on the plane.
Good for hole shot, not so much for top speed.

Harry.

[Mrdeli]

Thanks, so a 3 blade prop is best for top end then.

Cheers

Mark

[CJL]

More blades = more drag.

Therefore you get slower top end but better aceleration.

CJL

[Hightower]

A one bladed prop is the most efficient

[ian parkes]

Does engine size and the number of propellor blades etc have any standard .

I have noticed most bigger engines I see have a 3 blade prop but my little Honda 20 has a 4 blade .
Is it worth changing props , i presume Honda have just fitted a good alround prop for the 20 engine . Is there a way to get any advantage with a different prop considering the engine is pushing a small SIB .

[codprawn]

Originally Posted by ian parkes

Does engine size and the number of propellor blades etc have any standard .

I have noticed most bigger engines I see have a 3 blade prop but my little Honda 20 has a 4 blade .
Is it worth changing props , i presume Honda have just fitted a good alround prop for the 20 engine . Is there a way to get any advantage with a different prop considering the engine is pushing a small SIB .

They tend to put 4 blade props on small engines to get more thrust at slow speeds - for example when using the engine as an aux on a yacht.

A 3 blade will give you a higher top speed(or should).

My 15hp suzuki has a 3 blade prop which pushes my 3.1m at about 20 - 25mph. When I use the engine on my rib I may get a 4 blade for more low down thrust.

[ian parkes]

Thanks for the info . I have nothing to compare my Honda with , it sounds like changing props can be a bit experimental and expensive . What sort of money is a decent prop for the smaller engines like mine .

I am going to have to Pull a donut and take the family out a lot so the boat will often be loaded , is it best to stick with the standard 4 blade for general pupose use like this .
I did try it out with just me in at the weekend and it felt pretty quick downwind with a good tide running on the tamar . It was very windy and when I turned back into the wind the boat felt like it was trying to take off as it bounced in the chop . I had to slow down as I just couldn't hang on , quite scary .