#1
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Brackets
I have a 1977 Seacraft 19"8' center console and I am tired of wet feet.
I'm considering a bracket and filling in the transom. We rebuilt the boat about five years ago- paint, wiring and power, 150 Johnson w/ carburetors, great boat! What will a bracket do to the handling? I've heard bad things such as porpoising and difficulty at mid speed. What do ya'll think? |
#2
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a bracket will not help, it will just move the CG back and the boat will rest more trimmed up at the bow. A bracket might make it worse. This all assumes you want a self bailing boat. If you dont care about self bailing you can just close transom, drain to the bilge.....this is not safe though
You need to reduce the weight in the boat and/or redesign the drain system. For a boat of this size, its almost impossible to have self bailing with a 150 and a fishing load (people/gear/gas) and still have safe cockpit depth. Raise the sole, and it will bail, but you risk loosing someone overboard. Whats important is that it self bails at the dock !
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http://www.boatbuildercentral.com/ my rebuild thread: http://www.classicseacraft.com/commu...ad.php?t=22090 |
#3
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Quote:
If you install a Hermco bracket and stay with a relatively light 2 stroke motor like what you have, move the batteries to the console and move the gas tank as far forward as possible, it should be self bailing at the dock. My boat self bails at the dock, but the Seafari's have a little more weight forward than the CC's to begin with. You also have the option of moving the console forward a bit. I did a post on the pros & cons of brackets after putting one on my boat in 2007 and observing the effects of the altered CG. Here's the text of that post: BRACKET PROS & CONS (Posted 11-16-08) This question comes up often enough that I thought I’d start a new thread, as I had the same questions many of you are probably having. If you’re wondering, after having gone thru this learning experience, would I do it again, the answer is ABSOLUTELY! However, here are a few things you need to think about before you dive into what will no doubt be a more expensive project than just a transom rebuild! Don Herman, PaulB, Snookerd, Briguy, and Captains Chuck & Lloyd, feel free to chime in on anything I’ve missed or otherwise screwed up! (These comments apply to the 20' hull; for a 23, the pro's are the same, but the con's are probably less severe, as the bigger boat should be a little less weight sensitive, although I'd still be careful about running real heavy twins.) PRO’S 1. The biggest advantage of the closed transom/bracket set up is the safety aspect of keeping water out of the boat from a big breaking following sea. Unless you’ve been in that situation, it’s probably hard to put a value on it, but it’s a very big deal to me! 2. It's really nice for diving and it provides more room in the boat since you can eliminate the splashwell. You've essentially increased boat length by whatever the bracket setback dimension is. 3. It also keeps noise and smoke out of the boat, if you’re still running an old carbureted 2-stroke. 4. Improved Performance. Most before & after tests have shown that a bracket adds 2-3 mph in top speed because motor is running in cleaner water, allowing you raise the motor relative to bottom of boat. A similar increase may occur in optimum cruise speed. 5. Improved on-plane trim capability. Maybe it’s just the 25” shaft motor, but an aft shift of the motor increases the lever arm for both weight and thrust loads! Power trim definitely has more effect on running angle than I had with a 20” motor mounted on the transom. CON’S 1. Downsides are it changes the boat balance because you've shifted the weight of the motor aft, which moves the boat CG aft, and tends to hurt ride and increase min planing speed. On the 20' hull, the Seafari is less stern heavy than the cc models, so it's a better candidate for a bracket IMHO. 2. Low speed maneuverability will be slightly affected, because you've also shifted the boat's pivot point aft. In my own case, I found that the new Seastar hydraulic steering system had a shorter stroke than my old Hyanautic/home-made rig, so it doesn’t turn the motor all the way to the stops, which exaggerated the maneuverability problem. As near as I can tell, all the factory made hydraulic systems have the same stroke, and I haven’t figured out a fix to that yet. 3. You'll have to move the axle on your trailer back a couple feet to keep enough weight on the tongue. 4. All brackets I know of are made for a 25" shaft motor, which might be an issue if you're not repowering or having a bracket custom made. The higher that powerhead is from the water, the better! A few key things you need to pay attention to if you add a bracket: 1. Motor weight! Because of the CG issue, lighter is better! I would not consider the 450-500 lb 150 4S Yamaha, Honda & 150/175 Zuke, and the big block V-6 200+ hp 2 strokes because they're so heavy. That leaves the 140 & smaller Zukes, the Merc Optimax, the small block V-4 & V-6 E-Tecs among the new motors, and the earlier small block V-6 2 strokes. If you run offshore a lot, LESS (power & weight) is MORE. The light 20' hull will start to go airborne at about 20 kts in seas over about 3', so you don't need a big motor for that type of operation. I considered the 375 lb V-4 E-Tec rated at 115 hp (really about 120-125) but they weren't in production yet when I bought mine. I’m obviously not a speed demon, but the 150 (really 165) E-Tec at 429 lbs is overkill on power (will run almost 50 mph in flat water) and is the heaviest motor I'd consider. That said, it IS nice to be able to cruise at 4000 rpm/30-35 mph AND carry on a normal conversation! (It’s quieter than the 4-strokes at that speed.) It’s also nice to be able to outrun a thunderstorm if you screw up and get surprised by one! 2. Look for a bracket with the biggest flotation tank you can find, either a Hermco or an Armstrong designed for twins (but use a single on it). Reason is to maintain some self-bailing capability. My rig is still self-bailing, but just barely; I leave the scupper plugs in and depend on the bilge pump if I leave it in the water overnight. 3. Try to run the smallest setback you can with the motor you’re using. I could get away with 18”, so 30” on the Hermco is overkill, although nice for diving! (Don – how hard would it be to offer your bracket with various setback dimensions?) Making a custom bracket like Strick & Big Shrimpin did is a good idea if you have those kind of skills! 4. You will probably want to run trim tabs, a 4-blade stern lifting prop and maybe a Doelfin or equivalent to maintain good low speed (12-13 mph) planing capability for rough water operation. The flotation tank doesn’t help when you’re on plane, so all this stuff helps compensate for the weight shift. 5. If you already have hydraulic steering, all you need is new hoses, throttle and shift cables that are about 6' longer, at least if you rig them like Don Herman recommends, where everything runs down into the bracket and then thru the transom inside the flotation tank to keep a nice clean transom. If you have cable steering, you'll want to switch to hydraulic steering, which I'd recommend even if you don't go with a bracket. These are just some thoughts based on my own experience. A lot of folks are probably trying to make this decision, so you other guys with brackets, feel free to chime in!
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'72 SeaFari/150E-Tec/Hermco Bracket, owned since 1975. http://i188.photobucket.com/albums/z...Part2019-1.jpg |
#4
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Raise the deck, route scuppers out the back and put the rabuds in. That is exactly what I did and I still feel comfortable with the hull side height. I'm only 5'8" though too. Also moved the battery fwd and new fuel tank as far fwd as possible. All this gets you dry feet. Is it worth it?? That is the question.
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#5
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No Bracket - Go with smaller engine
Brackets have pros and cons. The best thing to do is look at engine weights, and power your boat for what it was designed to hold, a 115 to 130 hp 2 stroke on a scalloped transom. Your boat will run well and efficently.... The photo is my rig with a 115 4 stroke in Key West, and it ran very well for 8 years with that set up.
You may also want to construct an engine cover that prevents back splash from the engine well. And lastly, you might also need to review the rear deck design. A bracket WILL make you squat more so if your scuppers are already underwater.....a bracket may only make your deck draining issues worse. |
#6
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I have to agree with what's been said. Look at balancing out your boat by moving what you can forward. My 18' rides, floats and planes out great with a relatively light motor on a cutout transom. I eliminated the in-deck livewell, moved the batteries under the console, moved gas tank as far forward as possible. I also have the large ping pong ball scuppers. there really isn't a whole lot of space to be gained in an 18' by adding a bracket, unless you also get rid of the storage compartments in the transom.
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#7
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A properly designed and installed flotation bracket will add little if any squat to your boat. strick
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"I always wanted to piss in the Rhine" (General George Patton upon entering Germany) |
#8
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It's a simple mathematical equation which I don't have, sorry... I used to know a guy who would squat in his motor well.
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#9
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I have a 79 23' Sceptre with twin 150 ocean runners. I just measured my tub and its 28" back and roughly 4' wide. It self drains at the dock. I do not know who made it but they did a good job. I do get wet feet with three people in the stern. A 300 Zuke may be in the future next year and a little lighter than these two gas hogs on the back.
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