help! how to place surface drive
#1
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i did a search, and couldnt come up with anything reguarding how and where to install the drive... first off, this boat is an 18" deep vee, and the drive im installing is nothing more than a brass tube with a straight steel shaft running through it, with threads and a "drive dog" (notched piece of metal to spline with the cut out on the prop), and i will be hooking up the motor via a cable flex coupler. i know this isnt the most effecient way to do this, but its what i have, and i dont want to sink too much money into this boat as itll be my first surface driven boat. my questions are basically this: 1- how far down the transom (or up from the "keel") should i place it? 2- how much should it be up or down in relation to the water line i guess.. should it be parallel with the waterline and adjusted with trim tabs and battery placement? 3- how far back should the prop be from the boat? of course most of these will be ballpark estimates as the only person ive talked to thats built this little boat is ron olson (dumas short stuff deep vee-18), but he said he didnt do a surface drive. all help will be appreciated and further help me and other members in the future with setup!!
thank you!!
nate sanders
thank you!!
nate sanders
#2
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From: Auckland, , NEW ZEALAND
Hi There
Firstly yes i would run the tube parallel to the bottom of the boat, but slightly raised before it exits the transom, say 4-5mm above the bottom of the transom on a boat that size, also offseting the stuffing tube slightly to the right (say 2-3mm on your sized boat) will elimate prop torque, raising the stuffing tubes exit helps cut down chine walk. If your boat is setup 100% correct, it should not need trim tabs, they are a way of extending the hull slightly but otherwise its a bandaid fix for a boat that size... no trim tabs will save clutter and weight, I spend a lot of time setting my Mono's up and dont use trim tabs, unless the hull has a fundamental flaw you can do plenty of trimming by mocing the batterys and changing strut angle, theres an article by John Finch around somewhere called "Mono Mania" its worth a read for mono setup...
Peace
Firstly yes i would run the tube parallel to the bottom of the boat, but slightly raised before it exits the transom, say 4-5mm above the bottom of the transom on a boat that size, also offseting the stuffing tube slightly to the right (say 2-3mm on your sized boat) will elimate prop torque, raising the stuffing tubes exit helps cut down chine walk. If your boat is setup 100% correct, it should not need trim tabs, they are a way of extending the hull slightly but otherwise its a bandaid fix for a boat that size... no trim tabs will save clutter and weight, I spend a lot of time setting my Mono's up and dont use trim tabs, unless the hull has a fundamental flaw you can do plenty of trimming by mocing the batterys and changing strut angle, theres an article by John Finch around somewhere called "Mono Mania" its worth a read for mono setup...
Peace
#3
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thanks a lot crabstick! do you or anyone else have any guidance for the distance the prop should be from the transom?
#4
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From: Auckland, , NEW ZEALAND
IMO as far as you can get it within reason, i run my 30 inch mono on 8xl and 16 cells and run the prop about 3 inches off the transom, i would like it to be 4 inches, but its the way it worked out with the speedmaster strut and prather brackets i had.. Ive found monos will plane a lot easier with the prop further away from the transom, in cleaner water so to speak. if the prop is too close to the transom they sometimes tend to take a long time to get on plane and they fall off the plane easy too
#5
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again, thanks a million mate!! ive had some good times with some kiwi army guys at bagram af afghanistan, hella nice guys, it must be the country!! im going to get another brass tube, and i will be able to get the drive dog 2.5" away from the transom. with the drive offset to the right, does the rudder still need to be offset to the right? and how far behind the prop should the rudder be?i know this might seem like a bunch of mundane questions, but youre helping me and other people, thank you!!
nate sanders
nate sanders
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From: Annandale,
VA
ORIGINAL: Crabstick
IMO as far as you can get it within reason, i run my 30 inch mono on 8xl and 16 cells and run the prop about 3 inches off the transom, i would like it to be 4 inches, but its the way it worked out with the speedmaster strut and prather brackets i had.. Ive found monos will plane a lot easier with the prop further away from the transom, in cleaner water so to speak. if the prop is too close to the transom they sometimes tend to take a long time to get on plane and they fall off the plane easy too
IMO as far as you can get it within reason, i run my 30 inch mono on 8xl and 16 cells and run the prop about 3 inches off the transom, i would like it to be 4 inches, but its the way it worked out with the speedmaster strut and prather brackets i had.. Ive found monos will plane a lot easier with the prop further away from the transom, in cleaner water so to speak. if the prop is too close to the transom they sometimes tend to take a long time to get on plane and they fall off the plane easy too
My aquajet extreme with 700sc motor and 16 cells designed by offshore electrics had the prop about 1.5" from the transom to the front side of the prop. It took about 6 to 8 feet to get on plane. Not terrible unless you are racing.
#7
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so the farther back it is, affects how fast it pops up on plane, but does it affect speed? thank you for your input wheelnut! i like to experiment, just not if im a complete newb like i am to surface drives!!
#8

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From: Annandale,
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To save money my first attempt will be using my old hardware from the aquajet. It worked very good on the aquajet and pretty good on the profisherman. The aquajet was a 30mph boat so thats giving the hardware pretty good kudos.
#9
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im waiting man, im a slow deliberate builder...lol.. i might remove and reinstall almost all of the components at least 5 or 6 times before im happy with the current setup.



