Good day all...
I am doing some prop calcs for a 30 ft 8600 lb sailboat with a 26 hp low rpm engine. I have several props and pitches for the above, but I do not know what their shaft rpm would have been (not the crank). I even have a variable pitch for the fat 50 and other early Evinrude v4s.
Now before you say it... it supposedly only takes 7 hp for this 30 ft hull speed and in fact it currently has a single cyclinder Farymann that needs restoring. But its reportedly quite underpowered in head winds and rough seas. I will be restoring one of two Faryman V twins, one is a P22 from the mid 60s, and the other a S30 from the late 70s early 80s. Since the S30 isnt here yet, I'm not sure which until I disemble boath and decide which is the better candidate. Also before you say it... I can restore either with very few orginal equipment parts... rings, bearings, and gaskets and shaft seals are easily match up to similar duty from other engines. Now the injector pumps are a different story... but can be rebuilt by a good diesel shop. Both were running takeouts and pushed their respective boats to the marinas that repowered them (repowered with more horse since in 38 footers they were a bit underpowered. be just the extra I want in my 30. Oh and I will re-shaft (or turn a shaft) for whatever I need it to be for any prop I have... if they can get close.
It is my intent to prop for hull speed at about 2/3 rpm... thus having extra for tight qtrs and rough seas/head winds.
I am doing some prop calcs for a 30 ft 8600 lb sailboat with a 26 hp low rpm engine. I have several props and pitches for the above, but I do not know what their shaft rpm would have been (not the crank). I even have a variable pitch for the fat 50 and other early Evinrude v4s.
Now before you say it... it supposedly only takes 7 hp for this 30 ft hull speed and in fact it currently has a single cyclinder Farymann that needs restoring. But its reportedly quite underpowered in head winds and rough seas. I will be restoring one of two Faryman V twins, one is a P22 from the mid 60s, and the other a S30 from the late 70s early 80s. Since the S30 isnt here yet, I'm not sure which until I disemble boath and decide which is the better candidate. Also before you say it... I can restore either with very few orginal equipment parts... rings, bearings, and gaskets and shaft seals are easily match up to similar duty from other engines. Now the injector pumps are a different story... but can be rebuilt by a good diesel shop. Both were running takeouts and pushed their respective boats to the marinas that repowered them (repowered with more horse since in 38 footers they were a bit underpowered. be just the extra I want in my 30. Oh and I will re-shaft (or turn a shaft) for whatever I need it to be for any prop I have... if they can get close.
It is my intent to prop for hull speed at about 2/3 rpm... thus having extra for tight qtrs and rough seas/head winds.
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