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anpgr

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Posts: 2
Reply with quote  #1 
Hi forumites, 

I was wondering what is the max prop diameter that one can physically fit on a H27. 

My current prop is a fixed 2-blade and diameter I think is 14" - not sure about pitch. 

Thinking of switching to fixed 3-blade and was looking for recommendations on sizing. 

Particularly interested in combinations with Bukh DV10ME if anyone happens to have one of these old beasts installed.

What size prop do you have?

Many Thanks

Andreas
ernst

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Posts: 274
Reply with quote  #2 
Hi Andreas,

In general a 3 bladed propeller is not the best configuration for a sailing ship. It causes a lot of drag ( like a little bucket under the ship ).
The engine, shaft and prop are usually a calculated and balanced set. Just changing the propeller for a bigger one or different angles on the blades does most of the time not render the desired effect.

Cheers,
Ernst



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Happy sailing,
Ernst

Zonder geluk vaart niemand wel.
( .. Without luck nobody sails well..)
Bert

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Posts: 94
Reply with quote  #3 
Hi, I would agree with Ernst on the point he made about a three bladed prop in principal, but a 3 bladed produces more thrust so you can in theory throw a smaller prop ergo drag is a minimal factor. I opt for a 3 bladed every time. There is a mathematical formula for prop throw/ pitch/ engine match that I won't go into here but if you contact a propeller supplier with the information they will tell you your optimum size/ pitch to give you the best results for your boat,
anpgr

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Posts: 2
Reply with quote  #4 
Hi All,

many thanks for the advice. Just for reference, I finally fitted a fixed 3-blade prop 14x10 as I want the extra thrust. My engine is a Bukk DV10ME. The prop had do be modified slightly as the shaft taper was a non-standard type.

Best,
Andreas
Bert

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Posts: 94
Reply with quote  #5 
Glad you got sorted Andreas
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