Swap candidate?

[oldsub86]

So, let me know what you think. Is a 302 Ford with a Mercruiser 888 drive worth considering to replace an OMC electric shift stringer with a bad 307? It is momentarily the only thing I have found locally that might suffice. I can have the whole boat for a fairly reasonable price. I am told the outdrive has been "rebuilt" but the engine will likely require some work. IE - I wouldn't drop it in without tearing it down and checking it out. Am I going to have trouble finding replacement exhaust manifolds etc given the age? If I do go this route and repair the transom in the boat, will a later model Merc fit when I can find one and move forward again? Or will I need to modify a second time - which I would rather not do of course?

Randy

 

[HT32BSX115]

Re: Swap candidate?

Howdy,

If I'm reading this right you want to replace a "Stringer" with a Mercruiser eng/drive?

If that's true....I would suggest you find another boat unless you enjoy extensive wood/fiberglass repair.

You have to literally replace the transom and recut the "cut-out" to make it work. Not a job for most people. (it's probably not all that "hard" it's just not very cost effective on an old boat that won't be worth much more after the job is done)


You could also just fix the Stringer engine/drive you have there (which also doesn't increase the value of a boat much either)

Yes a later Merc engine/drive would "fit" (after you do the transom work) but you'd probably have to change the location of the side engine mounts since Merc doesn't use Ford engines anymore....


Regards,


Rick

 

[WizeOne]

Re: Swap candidate?

Also a lot of boats that used the OMC did not have full width inner transom structures. As the power assembly pushed from the stringers, not from the transom they did not need full strength transoms that were well tied to the hull, both at the bottom and the sides.

 

[oldsub86]

Re: Swap candidate?

Well, I am committed to fixing the boat one way or another. I don't think there is anything immediately wrong with the outdrive so initially plan to swap engines. The 307 Chevy/GMC engine has a deep knock and I think the fast and easy thing to do is to have an engine ready to drop in when the weather warms up. I will likely pick up a 350 since they are now more common. I am assuming most of the hardware from the 307 will transfer without issues.
However, everywhere I turn, folks tell me to forget the old OMC outdrive and move on. So, I have been watching for a Mercruiser that could be the swap. I need the whole boat for the shifter, steering etc so have watched for something that could be canibalized without worrying about the hull. There is a local boat of about the same size with the Ford 302 and 888 drive. I would rather have something newer but will have to watch for a wrecked boat in order to get the whole thing at a reasonable price. The old boat is a 72 Slickcraft 21.5 footer. I believe the boat to be in good condition and therefore worth the effort to rebuild the tramsom.

Randy

 

[a70eliminator]

Re: Swap candidate?

Also a lot of boats that used the OMC did not have full width inner transom structures. As the power assembly pushed from the stringers, not from the transom they did not need full strength transoms that were well tied to the hull, both at the bottom and the sides.

Hmm so what your saying is the hulls were built specificly for OMC drives period, and that peticular model Sea Ray or whatever could not be had with anything other than OMC?

 

[starsnstripers]

Re: Swap candidate?

Hi Oldsub, Fellow Slickcrafter here. Luckly my SS-215 came with a 165hp Mercruiser, However i owned a SS 235 with the 302 888 OMC and a frind of mine just boaught a 235 with a 350 OMC. If you have a rebuilt OMC on the boat then find a nice engine and put it in. Later on you can look for a Merc setup. There is an adapter plate on the market to install into your transom to accept the Merc. outdrive swap from OMC. Alot less fiberglass/transom work. The only concern i'd have if your going to a 350(and i'll check) Is that your )MC drive is the right ratio. A 350 usually have a 1.50:1. And yes your in luck the 888 is a 1.50:1 You'll love the ride. 18* Deep vee!

 

[WizeOne]

Re: Swap candidate?

Hmm so what your saying is the hulls were built specificly for OMC drives period, and that peticular model Sea Ray or whatever could not be had with anything other than OMC?

Don't know about specific models a70 and I did say some boats were built that way. Mine was and I believe you could have had my same model with a Merc, so they would have had to build two different transoms. In my case, to build out the transom and do it right, you'd want to cut back the motor mount blocks from the inside of the fiberglass transom then laminate in a curved transom assy. from side to side and top to bottom.

You could probably pull in each layer of transom material, using screws thru the outer back fiberglass into each successive layer of ply. Then keep driving the screws deeper as you added and pulled in the next ply.

 

[starsnstripers]

Re: Swap candidate?

The Slickcrafts Were factory with both OMC and Mercruisers same hull construction.

 

[starsnstripers]

Re: Swap candidate?

The only thing is the whole in the transom. I'm going to look into that adapter plate thing to swap to Merc from OMC. I'm not sure if Iboats offers them or not. I'll see what i can find. May have to do some eng. mount adjustment fwd/back/up/dwn.

 

[starsnstripers]

Re: Swap candidate?

Found an adapter plate! they do sell them on the sight i found.

 

[starsnstripers]

Re: Swap candidate?

Correction, this is an adapter plate from VOLVO to MERCRUISER Darn!

 

[mtnrat]

Re: Swap candidate?

Correction, this is an adapter plate from VOLVO to MERCRUISER Darn!

Who would do that???

 

[chiefalen]

Re: Swap candidate?

Someone who lives in a area that has merc dealers and no volvo dealers nearby.

Some places it's a 5 hour ride by car to get groceries. They think nothing of hopping in a small plane and flying a hour to the store.

 

[starsnstripers]

Re: Swap candidate?

Good point, With the OMC out of service and the problems with them and being obsolete, alot of people would like to do it. Someone should market an adapter plate to do the swap. I would think Mercruiser should have a huge interest in doing it since people want to swap to Mercruiser. Maybe an aftermarket one will be available sometime.