Since my Deere/ZF repower from Man/BW I have been unhappy with the
engine/trans performance with the exsisting Propeller 34/26/3 my Spare 35/28/3
both at Millers Island Propellers in Baltimore are trying to get to my now
preferred configeration of 30/20/3--as in 3 blade.
While cutting down a prop is "no big deal" repitching more than 2 down is more
challenging and the best that can be done is achieving a 30/24 out of my
34/26.
If you have ever had prop issues-you would find it a bit of a Black Art"-Read
Skeens Elements of Yacht Design, Gerrs Propeller Handbook, Use Boat Diesels,
and Michican Propellers computer services and you still get ranges of
"opinions"-that eventually is like trying on shoes--the only real test is to
try them--For example, "experts suggest" tip clearance from the hull ranges
from 5-17% of blade diameter-thats a big difference.
The 3/4 blade issue came forward when I dropped the Prop off at Millers
Island- the seasoned owner stated flatly that a 4 blade is appropiate for a
full lenght keel-not a 3 blade? First I heard of that-More balance in 4
blades-more efficient with 3 blades-thats in the books but more Dark Art
secrets.
Since I am "explaining" one last vent--the engine HP ratings. All these prop
calculations ask engine HP, So is that Intermittant or Continueous? With my
Deere 4045D thats 67 one way and 80 another.
Anyhow, after a while it all comes down to PRICE and Trail and Error.
Presently for a 30/20/3 NEW Prices range from $1200-$2200, Ahoy vs Michigan-Do
T&T members have suggestions on best price sources?
Bewildered in Bethesda Kevin/JOLIE
Since my Deere/ZF repower from Man/BW I have been unhappy with the
engine/trans performance with the exsisting Propeller 34/26/3 my Spare 35/28/3
both at Millers Island Propellers in Baltimore are trying to get to my now
preferred configeration of 30/20/3--as in 3 blade.
While cutting down a prop is "no big deal" repitching more than 2 down is more
challenging and the best that can be done is achieving a 30/24 out of my
34/26.
If you have ever had prop issues-you would find it a bit of a Black Art"-Read
Skeens Elements of Yacht Design, Gerrs Propeller Handbook, Use Boat Diesels,
and Michican Propellers computer services and you still get ranges of
"opinions"-that eventually is like trying on shoes--the only real test is to
try them--For example, "experts suggest" tip clearance from the hull ranges
from 5-17% of blade diameter-thats a big difference.
The 3/4 blade issue came forward when I dropped the Prop off at Millers
Island- the seasoned owner stated flatly that a 4 blade is appropiate for a
full lenght keel-not a 3 blade? First I heard of that-More balance in 4
blades-more efficient with 3 blades-thats in the books but more Dark Art
secrets.
Since I am "explaining" one last vent--the engine HP ratings. All these prop
calculations ask engine HP, So is that Intermittant or Continueous? With my
Deere 4045D thats 67 one way and 80 another.
Anyhow, after a while it all comes down to PRICE and Trail and Error.
Presently for a 30/20/3 NEW Prices range from $1200-$2200, Ahoy vs Michigan-Do
T&T members have suggestions on best price sources?
Bewildered in Bethesda Kevin/JOLIE
