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Old 06 April 2006, 19:32   #11
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Quote:
Originally Posted by 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 .
If your boat is going to be loaded all the time and you are getting reasonable speed stick with what you have - keep your eye open for a spare prop though - aluminium ones are cheap enough!!!
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Old 07 April 2006, 12:05   #12
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I guess my prop must be pretty well matched considering Honda offer the engine and sib as a package deal .
In their brochure honda offer a High torque version for big slow boats that has different gearing and prop .
Its a new science to me I understand engines very well but props etc
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Old 07 April 2006, 12:13   #13
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Quote:
Originally Posted by Hightower
A one bladed prop is the most efficient
A single-blade propellerwould be the most efficient - if the vibration could be tolerated. So, to get an acceptable level of balance with much less vibration, a two-bladed propeller, practically speaking, is the most efficient.

As blades are added, efficiency decreases, but so does the vibration level.

Most propellers are made with three blades as a compromise for vibration, convenient size, efficiency, and cost. The efficiency difference between a two- and a three-bladed propeller is considered less significant than the vibrational difference.

Four and five bladed propellors suppress the higher level of vibration and improve acceleration by putting more blade area into the water. They can also help to make the rake more effective in lifting the bow of the boat for added speed.

IMHO
Will
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