Bracket mock up

jasoncooperpcola

jasoncooperpcola

God
I cut some cardboard into the shape of what my bracket should end up. Its rather large. :nice:

Its 41" wide, 17" tall, and has a setback of 30". Totally submerged it will provide about 850lbs of floatation. Assuming my waterline stays the same, about 10" will be submerged. So that is about 550lbs of floatation.

First pic, the sharpie lines are where the outside of the stringers are. My plan is to extend the stringers out the transom and build my floatation box off the extended stringers.

bracket001.jpg


This is the basic bracket shape. I cut it too tall, so i just dropped it below the hull for now. Ran out of light and i will cut it correctly tomorrow. That is a 2' level on the top for reference to size.

bracket002.jpg


bracket003.jpg


bracket004.jpg


What do yall think? The outside edges of the bracket will be flush with the bottom of the hull at the strakes, and the bottom of the bracket will be flat. I will have 5" between the bottom of the boat and the bracket.

I think its the best compromise for the most floatation and also keeping the basic purpose of a bracket. RidgeRunner linked a site, http://www.hermco.net/ thier design has the most floatation, but i believe their design does take away some of the performance aspects of a bracket as they dont "swoop" up any.
 
being that i converted my v to a bracket, i would shorten the set back to just what you need to tilt motor. You really don't need to lift motor up all the way up. further back adds more leverage on transom and changes the center of gravity quite a bit. I always wished i went shorter with mine, but i bought a used Armstrong and beggars can't be to picky! But are building so you can do what you want. but looks good from here!!
 
I'd agree with MJ, make it shorter. I'd also make it taller, the biggest mistake in converting a boat to a bracket is mounting the motor too low. You also need to make sure you have a clean break(step) with the hull bottom. If you don't it acts like extending the hull length, which will add a lot of drag
 
The "clean break" area on my Stainless Marine bracket and the swoop are the precise areas where Hermco fills the gap.(Big Shrimpin's brackets too) By closing in a little more of that void on the underside of the bracket, they add floatation.
I don't think they go so far as to hurt the performance. Water rises as it leaves the rear of the hull but I watch where the water hits the lower and I know there is more room to add some additional floatation below the waterline. I was thinking of starting at 1.5" from the bottom at the transom with a swoop that winds up approx 2 to 3" higher than where I have noted the water hitting the lower unit. (Now there is 6" to 7" from the bottom of the bracket at the rear to the waterline on the lower) If it was 4'wide that would be a couple extra square feet of floatation at rest and yet completely out of the water on plane AND being 4' wide the boat would certainly be more resistant to transom sinkage when there are four people standing at the transom. LOL.. It would need to be light enough to reap the benefits yet strong enough to withstand the beating of a barely used 300XS Merc. :oh: Umm , did I stray?
 
longer makes it harder to steer i think. reverse is tuff to steer even on the sea ox, also when adding bracket you need to add a inch in height for every 6" of leanth. and as stated above a bracket should be at least for a 25" motor! shorter and it will get wet from following seas, some times getting swamped!
 
To test how the boat will ride with a heavier motor i am strapping a 30gallon livewell onto the bracket. If it rides good with then it will stay there. More room in the boat. As far as bracket height, my motor mount is five inches taller than the top of the bracket. I was thinking that running the edhes of the bracket flush with the strakes would help with any porposing issues. Ridge do you have any issues if you dont use tabs?
 
30 gal tank is ok for the test but its not going to show right, cause it will not fix the center yof gravity that is going to change when weight gets moved further back past transom.
 
Hmmmm. MJ that may be a good thing. My Mercury 200 is a 2.5L with a 25" shaft approx 395lbs.

I thought it was 1" up for every 12" back??? If that is not the case then i need to go back to the drawing board. One reason for trying to keep my bracket low is I am planning to install a port side transom door. I dont want to be trying to haul a tourney winning shark up 12" to get it over the bracket platform. Might not do the full width platform across the transom. I agree with Ridge 100% on the Armstrong design, they lose some valuable floatation with the sharp angle. How much of a clean break do i need from the strakes to the bottom of the bracket? Or can i get by with angling the bottom of the bracket just a tad, I would not lose as much floatation, but should still keep the bracket out of the water when running.

Ridge later on down the road i may go to a bigger motor. One reason for such a big and beefy bracket. I am also on the lookout for trim tabs, if i have the room to mount them.
 
Jason do you get on THT (the hull truth)? theres a guy on there building a Dusky he is very good with brackets and has actually started building his own for sale. His screen name is EDWARDPIC look him up he knows his stuff about bracket design, he could answer some design questions for ya.
 
No Kracker, i don't get on THT alot. Heck i dont even have username on there. CTerrebonne it will be a 23 after my bracket. :beer: 25 if you count the motor. 26 if you count the bow pulpit.
 
Just a thought, if i take pics thru out the build and document everything is it possible to get an inspection and possibly raise the hp and capacity ratings? The bracket will be a part of the hull not an add on? What do yall think? Or am i wasting time with an inspection?
 
Softy inspection is great to have, and they will leave you alone on the water! But they are not going to change the original capacity plate, don't waste your time.
 
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