prop clearences for 72" mono w/ twnis
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prop clearences for 72" mono w/ twnis
I'm buildnig a 72" mono (scaled up plans of doug's 48" mono) and will be running twins.
What are the typical distances between props "ctc"?
I scaled of a pic of a Bonzi 84" Classic (17" beam) and my rough calculations are 6.5" apart and 1.5" above the keel. Does this sound right?
What would be the closest I can place them w/o loosng too much efficency?
Thanks
Darin
What are the typical distances between props "ctc"?
I scaled of a pic of a Bonzi 84" Classic (17" beam) and my rough calculations are 6.5" apart and 1.5" above the keel. Does this sound right?
What would be the closest I can place them w/o loosng too much efficency?
Thanks
Darin
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RE: prop clearences for 72" mono w/ twnis
Depending on what your doing with your rudder. Aim for sufficient clearence for the largest diameter propellers you plan on running plus another 5/16" or so.
For surface drives aim for them to be level with the running surface where they exit the transom.
For surface drives aim for them to be level with the running surface where they exit the transom.
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RE: prop clearences for 72" mono w/ twnis
See there i am torn as to where to put the drives. I had planned on using twin inline rudder systems and starting with 75mm - 82mm props (twin 25cc engines).
With a single surface drive, propshaft center is +/-1/4" above the keel right? If i place the twin drives at the lowest place on the transom 4" apart, they could be as much as an inch higher. This places the boat further into the water. Is this ok?
What do I need to do to the bottom of the boat to reduce drag? keelsons? Step it?
With a single surface drive, propshaft center is +/-1/4" above the keel right? If i place the twin drives at the lowest place on the transom 4" apart, they could be as much as an inch higher. This places the boat further into the water. Is this ok?
What do I need to do to the bottom of the boat to reduce drag? keelsons? Step it?
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RE: prop clearences for 72" mono w/ twnis
ORIGINAL: nofords
I'm buildnig a 72" mono (scaled up plans of doug's 48" mono) and will be running twins.
What are the typical distances between props "ctc"?
I scaled of a pic of a Bonzi 84" Classic (17" beam) and my rough calculations are 6.5" apart and 1.5" above the keel. Does this sound right?
What would be the closest I can place them w/o loosng too much efficency?
Thanks
Darin
I'm buildnig a 72" mono (scaled up plans of doug's 48" mono) and will be running twins.
What are the typical distances between props "ctc"?
I scaled of a pic of a Bonzi 84" Classic (17" beam) and my rough calculations are 6.5" apart and 1.5" above the keel. Does this sound right?
What would be the closest I can place them w/o loosng too much efficency?
Thanks
Darin
Photos PLEASE.
P.S. One question....Why you scaled the plans of the 48 and you don't make it with the original plans of the 72 ????
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RE: prop clearences for 72" mono w/ twnis
because i didn't want to build the offshore version and the scaled 48" allows for the room I need to run twin engines w/o too much hassle on cg and engine for/aft placement
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RE: prop clearences for 72" mono w/ twnis
I see. Good to know. I just start with that hobby and Im asking all the time.....After all Im happy that always get one answer
I build also the 48'' and one a bit bigger 54''.
Somewhere on the forum are some post about.
Ok....another question.....Where is the photos? Or you keep it for surprise?
I build also the 48'' and one a bit bigger 54''.
Somewhere on the forum are some post about.
Ok....another question.....Where is the photos? Or you keep it for surprise?