is this possible?????

my question is more than just turning a ford 5.0 into a v8 mercruiser, its more like i have a 17' speed hull thats rated for max. 175 hp. outboard. i blew the motor some how or another and was thinking about the 5.0 i have in the shed. i was told in the past that you can change an imboard into an outboard but you cant go the other way. thay were saying becouse of the weight of the motors and such. the boat is rated max at 600lbs passenger weight and if i put an engine that weights twice the weight the engine is suposed to weigh, does that mean i will have a boat that has max pass. weight of 150-200lbs. and another thing is the hull strong enough for twice the hoursepower, which means 1 1\2 times the speed. give or take. any advice is appreciated and thanks ahead of time. toocan

 

Not practical for several reasons, weight being a major consideration. Find another use for your 302.

 

Hi toocanshan,

Close, but not quite- putting an outboard on a boat designed for an inboard can sometimes be done, but putting a big V8 on a hull designed for a 175 o/b is not going to work.

The 5.0 would probably be too much weight and too much power for your hull, not to mention you'd have no space left in which to sit.

 

well????

first off i was talkin to my father and found out that im not talkin about a true inboard i realy meant to say i\o. now sorry for the wrong wording but asuming everything is still a no go, then what is the differance in hulls between a factory built i\o and a factory built outboard??? thanks for everything guys......toocan

 

I have seen it done in drag boats. Place engine mid boat, exhaust out sides. Straight shaft at angle. You sit in the rear on one side, gas tank and battery on the other. Helmet, Chair, religious artifact are also require.

 

It depends on the hull design and the manufacture. Often, usually in larger hulls both I/O and an outboard versions are available, though there are some structural differences, the hulls generally are the same.

It would be possible to install an I/O on your boat, but you'll have to fabricate an awful lot of stuff, like engine beds, possibly bottom stringers, cut out the splash well, build an engine enclosure, fuel tank(s) relocation, etc. You would also have to convert the 302 over to marine. This means a new cam, heat exchanger, thermostat with housing, exhaust manifolds, risers, steering equipment and of course an outdrive and it's related gear.

It would be helpful to know what hull you plan on doing this to (make, model, year, etc.). Most 17' powerboats are outboard equipped because they are relatively light and don't eat up valuable cockpit space, like an I/O engine box does. Weight is a big problem with a V8 outdrive arrangement. The total assemble is well over 1,000 pounds. When compared to your outboard, you can see the problem and why larger boats can carry them, but not smaller.

It depends on which boat you have, how it's configured, it's bottom loading, rated capacity, etc. By the time you add up all the costs associated with this type of conversion, you could have a very healthy outboard hanging back there, plus no itching from all the 'glass work you'll have to do.

The answer is it's possible, but costly and not easy, which is why I tried to steer you away from it in the first post.

 

Well, to answer your original Question first: yes, everything is possible............
is it sensible? No.........
To sum up PAR´s valuable input: leave it! It´s never worth the effort.

Regards
Richard

 

Someone already said "anything is possible". I have in my collection a couple examples:

The most relevant: 1972 Champ XVII, 17'. Was originally a Ford 427 Volvo I/O. I got the hull only and converted it to a 235 V-6 Evinrude on a transom bracket with jack plate. After many years of running it that way, I am now converting the boat to 428 SCJ inboard with a Berkely jet drive.

Similar: My 1973 16' Donzi has a "5.0" that dynoed at 486 HP. IIRC the original 302 it was delviered with was around 275 HP.

A lot depends on how insane you want the boat to be..or how insane you are.

 

thanks for all you guys and i will try to get some pics of my hull on here so maybe someone can give a guess at what it is. "year, make, and model"

 

this is more what i was thinkin, without all the show of course!!!

 

toocan:

The boat you show above would have a V-drive, and is an inboard, not an I/O. There are other on-line forums that likely would answer your questions better - check this one out....

Hope that helps!

Jim