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post #11 of 23 Old 07-08-2013
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Re: 3 blade prop or two blade folder

You may have the option of re pitching the 18X17 to an 18X15. Then the cruising would be 2000 rpm.
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post #12 of 23 Old 07-08-2013
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Re: 3 blade prop or two blade folder

I was a partner in a Vlaiant 40 with my old pal Daryl. The boat came with a fixedd three blade prop. I talked to my friends at Max prop about a new Max prop. They said they would give me one. I said, "Yippeee!". But I quickly learned that the fixed three blade would power the boat effortlessly at hull speed and stop the boat on a dime in the slip. I kept the 3 blade fixed prop and never took them up on their kind offer of a Max prop. There were a few times when sailing I would curse the decision but not often.

I had used Martecs on three boats too and I never had an issue with them. I learned to keep my fingers crossed.

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post #13 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

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Originally Posted by bobperry View Post
I was a partner in a Vlaiant 40 with my old pal Daryl. The boat came with a fixedd three blade prop. I talked to my friends at Max prop about a new Max prop. They said they would give me one. I said, "Yippeee!". But I quickly learned that the fixed three blade would power the boat effortlessly at hull speed and stop the boat on a dime in the slip. I kept the 3 blade fixed prop and never took them up on their kind offer of a Max prop. There were a few times when sailing I would curse the decision but not often.

I had used Martecs on three boats too and I never had an issue with them. I learned to keep my fingers crossed.
>>>And there's the rub. Efficiency. I think that three blade fixed will get you a lot further in the long run per gallon diesel. On long voyages it will add up significantly. It is designed for max efficiency at your hull speed if sized correctly to your engines RPM. A folder and even a feathering prop could not attain that level due to the fact that the designer had to make many compromises to facilitate folding. They are brilliant compromises though.
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post #14 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

for what it's worth, I am an old evenrude mechanic.. I remember somewhere in my training one of the instructors saying that the best prop would theoretically be a "single blade." I cannot remember what the logic was, but I know two baldes was considered the best option for speed, 3 blades was for general purpose and 4 blades was typically for towing...
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post #15 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

A single blade has the least loss from drag (friction), but can't be balanced efficiently. So the next best is 2 bladed.
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post #16 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

I had a Maxprop on the last boat and loved it, but have not been able to justify the expensive of one for the new boat (or at least not had the money for one that could not be more usefully spent on something else. We have a standard 3 blade and it works fine. Like you we do not motor very much.

Finishing our major refit. Our trip to Newfoundland is off because it is too late. Hoping to go to the North Channel instead.
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post #17 of 23 Old 07-09-2013 Thread Starter
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Re: 3 blade prop or two blade folder

Hmm so the panel thinks going folding is a good idea with the Gori edging out the non geared types.

I will keep the 3 blader as a spare or in case I lose my marbles and decide to motor sail up wind for days at a time.
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post #18 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

I have a 4 blade MaxProp Classic II on my SD50 saildrive. I love it. I get nearly zero prop walk in reverse. The boat really behaves so well in reverse that I actually find it easier to go stern into slips.
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post #19 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

TQA:
Yes, think that's a good way to go. Only caveat with the Gori is that growth on the prop may prevent it from opening properly. Normal care of your bottom should eliminate that problem.

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post #20 of 23 Old 07-09-2013
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Re: 3 blade prop or two blade folder

Let me get this straight.

You are over propped but you are happy with the sailing performance with a fixed prop. You are cruising in an area where fouling is a problem. But instead of getting a smaller or finer pitch fixed prop which is cheap, functional and can't fail (unless it falls off ), you are considering spending a bunch more on a folder (or similar), which requires more care & maintenance.. and introduces another thing that could go wrong. Hmmmmm. What am I missing here?

If sailing performance was an issue I could understand it but....
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