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Old 22 April 2007, 05:55   #1
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4 blade props

I've been looking at various props on ebay.com for my Johnson 140 (same as suzi df140). I came across a number of 4 blade props. Are there any advantages with these? The prop I have is fine in terms of speed/load etc but I want to get another to use as the main and use the current as a spare.
My current prop is a 3 blade 14X17 aluminium jobbie....
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Old 22 April 2007, 06:22   #2
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I think the general rule about numbers of blades on a prop is that the more you have the better balanced it's going to be and that it gives you better acceleration (holeshot).

You will suffer at the top end though, as props with more blades are less efficient. I dought that you will notice any or much difference with your setup though when comparing 3,4,5 bladed props with the same pitch and diameter!
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Old 22 April 2007, 17:25   #3
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Other factors for going to a four blade prop are;

1. Gives higher torque, effectively giving you more low end grunt.
2. Is useful if your boat will be carrying heavy payload but you still want it it to plane.
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Old 23 April 2007, 17:00   #4
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Why I love four blade props

Tim

i changed to a four blade prop on my previous boat and loved it for the following reasons:

Better acceleration
Better mid range fuel economy
Better grip in foul weather
Better all round when carrying heavier loads
Slightly slower but not noticably, at WOT.

I am experimenting with props for the new booat and have not finalised decision yet.

Rgds
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Old 23 April 2007, 17:04   #5
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My 4 blade stainless is great - the acceleration is awesome but I think a 21" would be better than the 19" I have at the moment.
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Old 23 April 2007, 17:18   #6
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I curently have an aly 3 blade and am thinking of a 4 blade ss
can anyone recomend a prop suplier.
There are quite a few usa websites but I cant find anything local.
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Old 23 April 2007, 17:45   #7
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steel developments seam to know just about any thing to do with props
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Old 24 April 2007, 03:57   #8
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Ok so it all sounds quite positive. Should I get a 4 blade with the same pitch as my current 3 blade?
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Old 24 April 2007, 06:45   #9
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Thanks about the steel developments I will call them.

Do you find SS has an overall performance advantage over Aly. They say it is should as the baldes can be thiner. Is the diference noticable.
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Old 28 April 2007, 05:45   #10
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Quote:
Originally Posted by Tim M View Post
Ok so it all sounds quite positive. Should I get a 4 blade with the same pitch as my current 3 blade?
I am on the verge of ordering now. Can anyone answer the above question?

Sounds like a 4 blade is the way to go....
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