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Author Topic:   Engine Brackets REFERENCE Article
jimh posted 02-16-2001 06:42 PM ET (US)   Profile for jimh   Send Email to jimh  
This message thread is for comments and follow-up questions on the REFERENCE section article on Engine Brackets which first appeared February 16, 2001.

andygere posted 02-16-2001 07:24 PM ET (US)     Profile for andygere  Send Email to andygere     
Great addition to the reference section. I would love to hear from anyone who has done a Sea-drive to engine bracket conversion. I've seen a number of otherwise desirable Sea-drive boats advertised for sale, and know of one locally that may be for sale soon. Depending on cost and complexity, converting a former Sea-drive whaler may be one way to obtain a whaler with the desirable (IMHO) full transom.
awares posted 02-16-2001 08:01 PM ET (US)     Profile for awares  Send Email to awares     
What is available for a 1968 13' Whaler. I
want to mount a new 20" shaft motor with power tilt and trim.
FiremanLI posted 02-21-2001 09:35 AM ET (US)     Profile for FiremanLI  Send Email to FiremanLI     
I enjoyed reading the article on Engine Brackets. But if they are so great than why doesn't Whaler produce them any more? Why have most producers stop making or offering brackets.

I also hear that the Whale Drive had some problems it that it was hard to attached the drive to the stern of the boat and keep it attached.

hauptjm posted 02-21-2001 10:40 AM ET (US)     Profile for hauptjm    
See page 24 of cetacea. I have an 18ft. Outrage that was originally a SeaDrive. Converted to Armstrong Bracket in '95 with new power and Hydralic steering.
RHLOOS posted 02-21-2001 12:57 PM ET (US)     Profile for RHLOOS  Send Email to RHLOOS     
awares, west marine has a manual jack plate with a 5" vertical adj. don't know the back-set, but i'm sure it will 3-5 in. ROB
andygere posted 02-22-2001 01:11 AM ET (US)     Profile for andygere  Send Email to andygere     
I didn't realize your boat was a former Sea Drive. I guess I assumed it was converted to an Armstrong from a Whaler Drive. How much fiberglass work was involved with removing the old Sea Drive? Was it just a matter of filling some bolt holes, or was there substantial structural work done? Also, I am curious about the large setback of the motor. What's the advantage, and does it impact static or dynamic trim of the boat? By the way, your Outrage is among the nicest I've seen. I'm working towards getting my Montauk into that kind of shape. The seatback rodholder cushions finally arrived today!
hauptjm posted 02-22-2001 10:00 AM ET (US)     Profile for hauptjm    

The amount of work to convert to a bracket was not as much as you would think. I did not own the boat when it was done, but the dealer here in New Orleans that did, filled me in. The basic structure that Whaler put into converting the cut transom into a full transom is fairly substantial. The dealer did use real heavy-duty stainless fasteners and backing plates. The set-up is now a little over 5 years old, and not showing any signs of weakening in the least.

As far as the setback: mine is pretty far back for an 18ft. boat. But, the results are fantastic. My engine runs high versus waterline, my trim angle feels almost infinite and performance and efficiency is greater. I've run the boat with several conventionally rigged 18s, and there is a discernable difference. One thing takes a little getting use to, engine swamping. When I come down from a run at speed, the stern naturally sets as the boat slows. When the stern sets, the engine is approximately 70% engulfed by the ensuing spoil off the stern. My Oceanrunner handles this without a beat. The topside venting has snorkels that run straight down inside the engine cover that shed the water right out. Still it took a little getting use to.

Thanks for comments regarding her condition. I'm sure you will have that Montauk looking like you want in no time. I still have a soft spot for Montauks. It's clearly one of the best boats ever made.

jimh posted 02-24-2001 10:49 PM ET (US)     Profile for jimh  Send Email to jimh     
In reply to FiremanLI who comments about the discontinuance of brackets by "most producers".

If anything, there seems to be a huge INCREASE in the number of boats offering factory installed brackets, especially among boat makers who are regarded or want to be regarded as "top line" makers.

I just spent three days and 200 miles on the water cruising SE Florida and the ICW, and by far the most commonly seen set up was twin outboards mounted on large truss-style setback brackets on boats in the 25-32 foot range.

Adding a truss style setback bracket adds about $4,000 - $5,000 to the price of the boat. That's the cost of the bracket itself,
installing it, adding hydraulic steering, more complex rigging of controls, fuel, etc.

So you will never see this on some 18-foot bowrider built to sell for a price point around $9,995.

But on high quality boats built for performance, it is pretty much the norm these days. Just look at Regulator, Contender, and other "offshore" style boats.


jimh posted 02-25-2001 08:30 PM ET (US)     Profile for jimh  Send Email to jimh     
I happened across a lightweight bracket designed for smaller outboards and intended to permit 20-inch shaft engines to be mounted on 15-inch transom.

It is made by T&H Marine and retails for under $100. It was available at several marine outlets in Florida.

It looks like it would be a good choice for repowering an older 13-Sport (that has a 15-inch transom) with a newer engine with a 20-inch shaft.


jimh posted 02-25-2001 08:42 PM ET (US)     Profile for jimh  Send Email to jimh     
As of tonight, Sunday Feb. 25th, I have revised and expanded the engine bracket article. I also plan to a few photographs and illustrations to it in the future.


lhg posted 03-01-2001 01:13 PM ET (US)     Profile for lhg    
Further to FiremanLI's bracket issue and Jimh's response, I'd like to add a few more comments.

The transom bracket concept has now evolved into two distinct design forms. The first, of course, is the original concept of the bolt-on fabricated aluminium bracket which as JimH mentions, is still very popular and widely used, with setbacks of 26", 30" or 36" being standard. The application here is for those hulls of a more "classic" full transom design, usually on boats where the classic design elements persist. With the new revived interest in classic hull forms, and re-introduction of many older designs by their builders, the bracket is finding continuing success as alternative to the Euro look. Many love the way these things look, and prefer this to the following.

The second, and now being used by many, including Whaler, is the so-called "Euro" look, where this transom configuration incorporates the "bracket" into the glass mold, often notching the "Vee" of the hull back 2' from the motor mounting position, as a bolt on bracket does. The concept here is that this accomplishes the same swell coming off the hull and allows for higher mounting heights, and better performance. And most importantly, for advocates of this design theory, the cost of producing this portion of the boat is greatly reduced and it's design is integrated into the hull with swim platforms, etc. It also provides an additional 2' length to "sell" and price accordingly. As an example, BW's Outrage 26 is really a 24 with a built in Euro bracket of 2'. Sea Ray has been doing this for years and they brought it over to Whaler.
I recently saw an Edgewater 26, and it is done this way also. It's not hard to understand why many boats are being designed this way, but for some reason the "bracket look" which is so popular, has been lost.

So there are clearly two distinct hull forms here, and a buyer simply has to decide which form he prefers.

Regarding BW's introduction of the Whaler Drive units in 1987, this was something that Whaler had to do at the time, because brackets and full transoms were becoming popular, and the engine manufacturers were coming out with the Counter Rotating 25" shaft engines. The OMC Sea Drive started most of this, but then couldn't compete with the less complicated bracket/traditional out-of-the-box outboard setups. The problem BW faced was that their hull molds for the 20, 22 & 25's were notched transoms using 20" twins. So the full transom had to be built up after the mold, capped with a stern deck mold, and then a Whaler Drive bracket bolted on. Costly, but it gave the Outrage/Revenges the desired look, and allowed for 25" twins.
JimH has discussed the pros and cons of Whaler's bracket.

It is not widely known that when Reebock took over, they also continued the bolt-on bracket idea, but switched to an outside supplier in Ft Lauderdale who made a fiberglass bracket in the same form as the aluminium ones, riding clear of the water when planing. It was used on the 23 and 27 Walkarounds, 91' - 94', but was quite cleverly concealed by the deck design which eliminated the full transom look.

CarlRobert posted 03-16-2001 11:40 PM ET (US)     Profile for CarlRobert    

I am looking for a lightweight bracket for my 13' 1962 15" transom. I am unable to find a website for T&H Marine, or anyone selling them in the CA Bay Area. Can you provide the names of the marine outlets in FL that carry them or a source of specs on the brackets?

Much thanks....CarlR

Tom W Clark posted 03-17-2001 12:00 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     

You can buy T & H Jacking Plates from (see their 2001 catalog, page 344) or visit T & H Marine's web site: Hyperlink

lhg posted 03-18-2001 03:55 PM ET (US)     Profile for lhg    
CMC (Cook Manufacturing Co) also makes Static (non-moveable vertically) Lift/Setback Plates. They are more well known for their Hydraulic transom jack and Tilt n Trim units, but they do make the static plates also.

One is of particular interest, as it has no setback, only non-adjustable lift, allowing a 5" longer engine to be mounted on a transom. It is made from 1/2" aluminium plate (giving only a 1/2" setback), with a 1" flange for stiffness. Don't know what it costs, but doesn't look all that costly. This would work nicely for someone who is afraid of changing the balance of a hull, and doesn't want more setback. For anyone re-powering a 13' hull with 15" transom, I would think this set of plates would be the minimum to do to accomodate a 20" engine. CMC's part # is 50012.

CarlRobert posted 03-18-2001 05:00 PM ET (US)     Profile for CarlRobert    
Anyone ever install a jack plate on the 13'? It appears most models require the two top bolts to be mounted through the transom, with the bottom of the plate attached to the transom with lag screws (due to that "lip" on the interior of the transom 6" from the transom's top. Is this right? None of the dealers in my area have ever installed one on a 13'...Carl
jimh posted 05-05-2001 09:10 AM ET (US)     Profile for jimh  Send Email to jimh     
UPDATE: May 5, 2001
I have added several new photographs to the article on Engine Brackets. I didn't quite have these ready when I first published the article, but I think they really help to illustrate the several kinds of brackets. They also show some details of installation.

Article: Engine Brackets

I also show the new Edgewater 260 hull as an example of a molded in bracket. As LHG commented earlier, you get the functionality but lose the "look" of the bracket.

OutrageMan posted 05-05-2001 12:14 PM ET (US)     Profile for OutrageMan  Send Email to OutrageMan     
One thing that my father pointed out to me whlie we were in Putna Gorda was that a lot of the boats with brackets and set backs were done because the I/O's were rotted out from all of the salt.

jimh posted 05-12-2002 09:49 AM ET (US)     Profile for jimh  Send Email to jimh     
The article on Engine Brackets ( Engine Brackets ) has now been split into two articles.

The original article retains the discussion of the reasons for using brackets and their history in Boston Whaler boats.

A new article, Standard Transoms and Brackets, now shows in greater detail the process of installing an aftermarket setback bracket on a Whaler with a standard transom.

The new article also illustrates the problems in steering forces and steering thrust which result when using side mounted hydraulic cylinders.

I am in the process of adding setback brackets to my own boat and I should have more details and photographs available as this work progresses.

Both articles point to this message thread for comments.


Richard Quinlivan posted 05-12-2002 11:22 PM ET (US)     Profile for Richard Quinlivan  Send Email to Richard Quinlivan     
The use of brackets will move the cg aft and trim the bow up as has been noted already. My boat gets into a mid speed porpose with very little trip. I fear that on some boats the bracket will make the porposing more of a problem. At the top end the bracket is good since it gives the trim more leverage as well as moving the cg aft so that more of the boat can come out of the water.

Dick Quinlivan

jimh posted 05-14-2002 08:52 AM ET (US)     Profile for jimh  Send Email to jimh     
Based on some feedback which indicated less than startling clarity to my drawings showing the relationship between the tilt tube orientation and the steering forces, I have revised the two drawings that try to illustrate those situations. I hope they are better illustrations. I also corrected a few errors in the text.
jimh posted 05-14-2002 09:00 AM ET (US)     Profile for jimh  Send Email to jimh     
[Fixed dead link to T&H site.]
CaptCornchowder posted 05-18-2002 08:50 PM ET (US)     Profile for CaptCornchowder  Send Email to CaptCornchowder     
Jim do the twin 115's exceed the max H.P. for the 18 cc
lhg posted 05-20-2002 12:41 AM ET (US)     Profile for lhg    
Capt - yes, the boat is rated for 150HP. But she will handle the 115's. Care needs to be excercised if you're running over 45 mph. The twin non-counter rotating Laser II performance props create a lot of torque, and the transom will jump sideways if power is pulled too fast.
Ready2Rip posted 05-20-2002 07:33 PM ET (US)     Profile for Ready2Rip  Send Email to Ready2Rip     
So now that Springfield Marine is out of the bracket business, where can you find an adjustable non-hydraulic setback bracket for a larger motor? I searched everywhere for a Springfield, but couldn't find one.
dfmcintyre posted 05-21-2002 07:05 AM ET (US)     Profile for dfmcintyre  Send Email to dfmcintyre     
Ready -

Try Cook Manufacturing Corp... they make the CMC bracket. Tx 580-252-1699. The model I used to handle a 200 Yamaha is the manual lift model #ML-65.

Happy with it.


dfmcintyre posted 05-21-2002 07:07 AM ET (US)     Profile for dfmcintyre  Send Email to dfmcintyre     
One additional thought....

If you don't want the polished look, take it apart and have it painted. However, best is to have it powder coated, either the hull or motor color. My paint job flaked off last year, so I'm going the p/c route.

Best - Don

lhg posted 05-21-2002 12:04 PM ET (US)     Profile for lhg    
Bass Pro sells a nice unit by T&H, but only available in 6 or 8" setback. Downside, is they're painted black, since most are used with Mercs. Might not look good with other brands.

Have you tried calling Springfield Marine directly? I wouldn't be surprised to see them get theirs back in production, and the silver anodizing works with any brand engine.
I still think these, and the T&H units are the smallest, least obtrusive looking units on the market.

Airborne posted 05-22-2002 02:41 AM ET (US)     Profile for Airborne  Send Email to Airborne     
I converted a 22' outrage with twin Sea Drives to an Armstrong Bracket, 250 ficht and 15 4 stroke motor. I am very happy with the new system. Nice ride!
sprytle posted 08-28-2002 08:41 PM ET (US)     Profile for sprytle  Send Email to sprytle     
We have a 1984 Outrage 19' which we bought 2 years ago. It is a closed transom/full stern with a V6 150 hp 1984 OMC Sea Drive mounted on the bracket that was sold with that model. The center of gravity on the boat is so far aft that we get engine swamping coming off plane, big bow pitch-up at intermediate speeds and a fugly looking set of the boat at anchor. We had the engine rebuilt with a new powerhead when we purchased it, and its performance has been okay with light use over the past two summers.
We like the hull a lot, but would like it a lot more if we could reconfigure it with a new power plant set-up that would bring the center of gravity forward. We would also like to go to an oil injection system, as we find pre-mixing oil and gas impractical, and adding oil into the gas tank to be unwieldy, messy, and a pain in the neck.
We are considering two options, one to get a newer, lighter engine and bracket combination that would give us adequate hp and bring the center of gravity forward. If, however, a new engine and bracket would not significantly reduce the stern weight and help the COG situation, it was suggested that we cut the transom and mount the engine without a bracket.
Any suggestions or comments much appreciated.
Bigshot posted 08-29-2002 11:01 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
You can not cut the transom. You will have to get a bracket and i recommend an Armstrong or equivelent with foam filling. It will increase the flotation in the stern. Look to spend about $2000+ installed.
jimh posted 08-29-2002 11:21 AM ET (US)     Profile for jimh  Send Email to jimh     
[These recent posts were made in August,2002; the forum software gets confused some places about the year--jimh.]

Sprytle: Can you clarify for us? You have both a Whaler Drive ("the bracket that was sold with that model") and a SeaDrive? That would really move the engine aft. I think you mean you have a SeaDrive, period.

I think you are in an ideal situation, since you have a full transom boat which can easily be converted to a setback bracket. When the SeaDrive is done, remove it, repair the holes, mount a bracket, and get some newer power. If you have your heart set on 4-stroke engines or low-emission 2-strokes, you may have a lot of weight on the transom.

If you really want to return to a notched transom, sell the full transom boat (which will be easily done) and buy one of the much more common notched transom models. That would be far less work than trying to convert from your boat.

jimh posted 08-29-2002 11:58 AM ET (US)     Profile for jimh  Send Email to jimh     
Also, there was no 19-Outrage model made in 1984. Do you have an 18-Outrage?
David Ratusnik posted 08-29-2002 01:48 PM ET (US)     Profile for David Ratusnik  Send Email to David Ratusnik     
sprytle- No, no, no, do not cut the transom. I've seen an 18'OR just like yours where the SeaDrive was converted to a light modern bracket, hydraulic plus new power. That full transom actually adds value to the boat - backing down it stops the sea from coming in on you. Fisherman like the set up. Recommend R/R the SeaDrive, fill holes, add light powdercoated bracket plus hydraulic steering for new power. A small hole needs to be cut for the steering, gas, and electrical bundle to the new engine. .03 David
hauptjm posted 08-29-2002 03:15 PM ET (US)     Profile for hauptjm    
sprytle, you have the same boat that I do, a 18ft. OR. It's an extremely rare model. Don't alter it. You can usually get a pretty fair premium over a traditional notched transom. If you're concerned about repowering, don't be. Mine was done back in '95, and I love it. Check out Cetacea pg.24. If you're dead set on a notched transom, sell the one you have, and buy a notched transom. You'll probably come out ahead on the premium.

Last summer, I was offered $18,000 as is with a '95 OMC 150 Oceanrunner. And I didn't take it. Truth is, my three year old has decided it's his, and he said no way. I've got to say, it's the best boat I could have found for what I wanted to use a boat for, and for the cost of a repower when the old OMC finally gives out, it will still keep me happy with the dollars spent.

David Ratusnik posted 08-29-2002 03:40 PM ET (US)     Profile for David Ratusnik  Send Email to David Ratusnik     
I rest my case. D
jimh posted 08-29-2002 04:09 PM ET (US)     Profile for jimh  Send Email to jimh     
I'll have to re-read my own article to see if I mentioned this, but I want to add that the bracket mounted engines should probably always be longer shaft engines than original standard transom mounted recommendations.

I have moved my 20-inch twin engines off the transom and onto a 10-inch bracket, and I see that the power heads are running a bit closer to the water than one might like. This happens when slowing down and coming off plane. I have not seen what will happen in rougher water.

Following good advice from LHG, I would probably opt for 25-inch shaft engines if I re-powered. I would mount them up a hole or two and raise the bracket as necessary. That should get the power heads out of the water.

PanMan posted 03-04-2006 09:25 PM ET (US)     Profile for PanMan  Send Email to PanMan     
I am starting a project to remove inboards, put a bracket and twin outboards on a 34' Silverton. This is one of the few forums where I've seen a lot of information on brackets. Has anyone out there seen a conversion like this? The Silverton is a 12 1/2 ft. beam boat, the transom is over 5 ft. hi - I'm anxious to find someone who can share some practical advice on this size of a boat conversion. Anyone out there seen anything like this?
Teak Oil posted 03-05-2006 11:22 AM ET (US)     Profile for Teak Oil  Send Email to Teak Oil     
Outboards aren't going to have enough torque to move that behemoth IMO, or be able to swing a big enough prop to allow you to maneuver at slow speeds in a crosswind. By moving the props from under the boat to two feet behind the transom you are going to lose a ton of leverage.

You will need the biggest displacement outboard you can find, probably the new Suzuki 300 four stroke if it comes out.

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