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Old 12-26-2004, 06:23 AM
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Default Internal Extension Box

I have a Stelling ext box on the boat now but what do you think about an internal ext box where it would move the engine forward about 6" and bolt in just like the inside transom mount. All it would need is a 6" longer drive shaft. This would move a lot of the weight forward. Do you think that moving the engine forward 6" and the change in weight balance make it worth it?
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Old 12-26-2004, 08:08 AM
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Default Re: Internal Extension Box

Originally Posted by sutphen30
i know of someone with a cat that has a slide system and slip joint shaft that can at will move engine back and forth 1 foot maybe even alittle more.
A lot of engineering in that system!
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Old 12-26-2004, 09:03 AM
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Default Re: Internal Extension Box

get a ballast tank so you can adjust on the fly.
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Old 12-26-2004, 09:37 AM
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Default Re: Internal Extension Box

Originally Posted by vette131
get a ballast tank so you can adjust on the fly.
Now that would just be too simple.
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Old 12-26-2004, 11:18 AM
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Default Re: Internal Extension Box

Cobra Marty I know many of the larger twin motor cats have the motors foward. Does make the boat run level in the rough. But I agree Sutphen 30, some weight in the nose would be a much easier test. Does your hull run nose high? Where do you boat, I am here on the upper bay near the chesapeake inn.
I tried 100lbs of lead shot in the nose of my motion amd It did help in the big water but I ended up building a tunnel tab and it helps a great deal and also adds a little on the top end.
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Old 12-26-2004, 02:05 PM
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Default Re: Internal Extension Box

It does run nose high and I never tries adding weight to the front. I have a single I/O and the center tab is out of the question. I have a condo at NorthEsat Isles. I was thinking of 2 inner transom plates with welded in 6" spacers to build the inside box. On the 36 spectre they move the motors forward at least 2-3 feet. My idea is to run flat.
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Old 12-26-2004, 03:11 PM
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Default Re: Internal Extension Box

Marty You are not far from me. I am suprised I have never seen you on the bay.
What did you plan to use for a driveshaft? Maybe the extended shaft from Imco would work. If you need any welding done I can help you out as that is what I do and I have a shop set up here at the house.
Maybe another idea, a rear motor plate would be more simple and stronger?

Last edited by mmwalters; 12-26-2004 at 03:16 PM.
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Old 12-26-2004, 05:28 PM
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Default Re: Internal Extension Box

I could have the stelling drive shaft lengthened or just have them build me a new driveshaft 6" longer. I thought that without the rear motor mount and just the int. box the motor would attatch just like stock bravo.
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Old 12-26-2004, 07:00 PM
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Default Re: Internal Extension Box

Instead of doing that cobra, why don't you develop a powered extension box? I have the adjustable stellings, and there wouldn't be much to powering it so you could adjust the drive height while underway. The hardest thing would be making the assembly water tight.
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Old 12-26-2004, 10:23 PM
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Default Re: Internal Extension Box

Remember the transon is at an angle, so when you go foward you will need the front of motor to go up in the boat
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