Zip Long Shaft Transom Motor Well required?

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Shelboss
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Zip Long Shaft Transom Motor Well required?

Post by Shelboss » Fri Mar 23, 2018 5:23 am

When using a long shaft (20") motor on the Zip, the transom is 5" taller at the motor well location. Aside from using the motor well for strength, do people with this configuration see water coming over the transom or does it stay pretty dry except for splashing? Would a vinyl boot also do the trick?

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hoodman
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Re: Zip Long Shaft Transom Motor Well required?

Post by hoodman » Fri Mar 23, 2018 6:25 am

I don't know what you mean by a vinyl boot or what that would look like. As you say the structure of the motorwell with the sides extending down to the bottom battens adds a huge amount of strength to the transom. You may be able to minimize the size of the motorwell if the cutout ends up close to the top of the transom. Hopefully, someone with Zip driving experience will respond, but sometimes on outboard boats like this if you very quickly come off plane you can get a wave coming over the transom.
Matt

Building a Geronimo......!
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Bill Edmundson
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Re: Zip Long Shaft Transom Motor Well required?

Post by Bill Edmundson » Fri Mar 23, 2018 6:58 am

Something to remember... If you are using Telflex steering the rod will extend quit a way to the side. You can widen the box or put a hole in the side for the rod to go through.

Hydraulic is more compact. But it cost $$$.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
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Roberta
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Re: Zip Long Shaft Transom Motor Well required?

Post by Roberta » Fri Mar 23, 2018 7:11 am

On a Zip the motor cutout goes down about 2-1/2" for a short shaft motor but goes up for a long shaft motor in order to get the cavitation plate on the motor to be at the correct level with regards to the boat bottom. The plans are drawn for typical short shaft motors of the day. Generally, if you were to draw the transom and continue the arc of the top of it without the cut out, for a long shaft motor, you would want to go up in the same area that you go down for the short shaft. There are several examples, on the forum, of what the transom will look like using a long shaft motor. Search the different Zip builds. I also recommend you have the motor you will be using on hand to make measurements, or at least get the owners manual, which will tell you the recommended transom height.

I would discourage not incorporating a motor well. It adds strength to the transom necessary for newer/larger motors and provides a place for the cables and hoses, besides preventing a swamping condition described by Hoodman.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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vupilot
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Re: Zip Long Shaft Transom Motor Well required?

Post by vupilot » Fri Mar 23, 2018 9:23 pm

For a long shaft motor on a Zip the motor will be above the motor well. Even when the motor is tilted up not much of anything will be "in" the well. The steering cable and rod would be above the deck so not a factor and no need to widen the well. You should not see water over the transom but you still want the well as it adds significant strength.
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Shelboss
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Re: Zip Long Shaft Transom Motor Well required?

Post by Shelboss » Sun Mar 25, 2018 10:37 am

Hi all, thanks for your replies! I think I have put the cart before the horse in not explaining what I am up to, so I started another thread that better addresses the entire modification. I have added a gallery with some pictures that should be up shortly. My term boot should probably read vinyl snap-on cover. In Vupilot's pic, it could cover the entire motor well area with an opening at the motor clamps. I have my 71 Merc 500 motor and controls and have modeled it as well as the cable bend radius for throttle and shift, I think those will fit within the cutout which will be narrower and deeper than shown. Yes the steering cable will exit thru the deck, hydraulic is not in the budget :lol:

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