I.O engine mount help

[bigeasy1]

I'm getting ready to do a transom replacement on my recently purchased 1974 Tsunami I.O,and have a few questions.
Asyou can see from the pictures,the short box stringers that the engine was mounted to,need to be rebuilt.The original mounts in the picture had a raised portion where the front engine mounts were fastened.
Should i make the new ones the same,or should i make them flat across the top for their whole length?.
The original engine was a 351 Ford,but i will be replacing it with a 5.7 350 GM.I figure that it might be better to make them flat across the top,and raise them if necessary when i get ready to install the new engine.
I'm also going to do the transom from the inside,i know that it's more work than from the outside,but i think it makes for a neater and more secure repair,and it doesn't compromise the integrity of the hull.
Any comments or help would be much appreciated.
The pictures in order are
(1)bilge area before cleaning
(2)bilge area after cleaning
(3)Raised motor mount area,showing the deterioted glass and substrate.
Should i make the new ones flat across the top,and are any measurements available for Mercruiser engine and outdrive placements,such as location of transom cutout in relation to engine height or placement
Thanks again guys.
John R.

[1bayouboy]

I dropped a 350MAG MPI FWC/ Bravo I in a sailfish (really sportcraft) back in March....

Installation diagrams with measurements are on the Mercury web site....there's also some on the installation CD. The sportcraft had pretty high stringers with aluminum angle plates through bolted on the insides. I think if you stick with the raised areas you will have somewhat better access under the engine. Not that you need to get there much, but sometimes you do....that's my $.02

[gigolot]

It might seem like a lot of work, it is more expensive than plywood but it will never rot. I am in the process of redoing the transom the one and only time on my 19'bowrider with a composite material. Check with your buddy that sells fiberglass he may have a comparable material to seacast.










If you go to transomrepair.com they have a good tutorial on removing rotten wood from the top with a chainsaw.


and a link to the rest of the pictures on the transom project:

http://www.classicseacraft.com/forum...b=5&o=&fpart=1

[EBEACH]

John,

That is a good question. I agree with the other post about access below. More importantly, on my set up, it had to be lower at the transom because the Y pipes, or part of the transom housing would have had an interference problem. That transom of yours looks to be in pretty good condition. It could be a bear to pull that out.

FYI, I just raised the whole deck cap to get at the transom, without having to cut anything. Not the best working conditions, but kept me from having to patch the inside back up.

Jim

[bigeasy1]

Thanks all, Jim,i'm the guy that that works with Joe,at Merton fiberglass I think he told you a few years ago about me trying to get this boat in western NY on lake Ontario.
Well,i finally got it,and so far the only serious problems are the rotted transom,and engine beds.
The deck floor is solid with no rot,and the fuel tank is in excellent condition,although we had to siphon forty gallons of six year old gas out of it.
Naturally all the other stuff like elec,controlls,gauges,hatch lids,etc are shot and need replacing.
What do you guys think of a 300hp 350 Mag MPI with a Bravo II or III drive,good choice? yes or no.
Anyone else have any reccomendations of any kind please feel free to tell me. Thanks for great info,and a super website.

[1bayouboy]

The Bravo II is really for large boats...it has clearance to swing big props. I went with the Bravo I just a save a few pounds and a buddy had some good props free (those aren't cheap....running about 1 grand for a BIII set). But...BIII with counter rotating tracks like a laser, no torgue roll, and very efficient.

[bigeasy1]

Oops.sorry about that,i meant to write Bravo I ,thanks 1bayouboy.So far the best price i got on the 350 Mag with the Bravo I drive was $10,200.00 which seemed pretty fair.The Bravo III is quite a bit more,(around 13,500).My original plan was to take my time with this boat,like maybe a year or more,as i have a couple other boats to use.I figured i'd sell them when i was close to finishing this one,so i could recoup some of my investment.
Well, now all i think about is the Seacraft,and work on it every chance i get.I'm actually starting to think(perhaps blindly)that i may be able to have it in the water by mid summer of 07.I think i've gone mad allready.

[abl1111]

You definitely want the Bravo 3 ! The performance is perfect. There was one for sale around here, at a mercruiser dealer, w/ 15 hours on it for a really good price ( Long Island ). As for the props - I got mine for a one time deal for $600.

[Ed]

You may also want to consider the Volvo 5.7L OSI with the XDP composite drive. Its a really good seller for us...

[1bayouboy]

Who was that price from...??? I bought thru www.go-fast.com and the price difference on a B-I vs B-III was about $400 on a "package". That $13k price sounds like the 350MAG Horizon, which is the fresh water cooled version.....