change out

girl-here

Cadet
Joined
Jun 3, 2004
Messages
6
has any one ever taken a inboard engine boat and made it an out board engine instead.<br />has been done?<br />wanting to try on 89 18ft sea ray<br /><br /><br />any advice?
 

JustMrWill

Master Chief Petty Officer
Joined
Aug 12, 2003
Messages
877
Re: change out

Anything can be done...I am a sure this has been done BUT...<br /><br />everything I have read here is that an I/O transom is not strong enuff to support the weight of an OB. To do this you would have to completely re-do the transom to support the extra weight...then you still might have problems with the center of gravity and how the boat handles since the hull was designed for an I/O.<br /><br />It would be easier selling your I/O and getting a different boat.<br /><br />-JustMrWill
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: change out

Ahoy, Girl. :) <br /><br />A lot of guys and gals will disagree with Will. What you propose has been done many times.<br /><br />Most commonly the transom is sealed and a bracket added to carry the outboard. Several companies make brackets for that exact purpose.<br /><br />Someone will be along soon who has actually done it.<br /><br />Good luck. :)
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: change out

It is do-able, and if done properly, can yeild a superior boat to what it was. The key is the transom. The transom on an I/O boat is generally not as strong, as does not go all the way across. Since the engine is bolted to the structure, and the outdrive is bolted to the engine, the forces are transmitted to the structure through the engine. the transom serves only to keep the water out and located the outdrive.<br /><br />On an outboard boat, the transom is stronger because the outboard is bolted to the transom, and the force is transmitted through the transom to the boat. In order to do as you propose, you will need to tear the old transom out, and lay in a new, thicker transom. You will probably need to rebuild the floor and stringer system to take the force. Often a pair of braces are added from the transom to the floor/stringer system to further strengthen the hull. The hole that is in the fiberglass is then filled with new glass layup, the new transom takes care of the hole itself. At this point, a bracket is the easiest route to go. A bracket will offset the outboard from the rear of the transom from 6 inches to a couple feet, depending on the bracket. The other alternative is to engineer a splashwell into the transom, basically configuring the boat like an outboard boat. Either way is a lot of work, and unless you really love this boat or just like to spend money on a challenge, you would be money/work ahead if you simply got another boat that better suited your needs. Good luck either way...
 

girl-here

Cadet
Joined
Jun 3, 2004
Messages
6
Re: change out

i am not looking into putting a alot of horse power, hp wil be about 95hp outboard, engine weight dont know yet.<br /><br />i figure that i am going to have to build up the transom. make thicker and have it supported by new floor stringers<br /><br />i have to tear floor out due to some rot in center stringer. i like to cruise softly and fish.
 

petrolhead

Chief Petty Officer
Joined
Oct 16, 2003
Messages
614
Re: change out

has any one ever taken a inboard engine boat and made it an out board engine instead.<br />
Doing just that right now! It's probably a completely different kind of boat but you may want to take a look at the photos in my earlier post "Yet another resto project!", which show the I/O removed, the hole filled, and the transom cut down and a splash well being built.<br />With a slow river cruiser like this old Norman 23 it's an easy job, Norman offered them with a choice of inboard or outboard when they were made anyway, with faster boats it'll be more difficult, C of G will be more critical etc..., but it can be done.<br />I've seen plenty of boats that had the conversion done the other way round too, outboard to inboard.
 
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