OMC to Merc conversion

[79Glastron]

Hello

I am a new user here and had a few burning questions that I couldn't find answers to using the search. First off the boat is a 79 Glastron ssv177lx 3.0 OMC. I am tired of the OMC drive always breaking and giving me general problems every time I use the boat, and plus the 3.0 is rusting from the inside out, time for a change. I would like to convert to a Merc alpha one drive and 4.3 V6. My question here is how should I go about closing the hole in the back, then re-cutting it to fit the smaller drive? Of course the drive must be centered in the boat, and the transom needs to be as strong as possible.
Thanks

 

[redfury]

Re: OMC to Merc conversion

The best way to re-power it would be to rebuild the transom completely and then cut out a new hole for the other drive unit, otherwise you risk having a pieced in unit fall apart down the road and start leaking ( or worse, sink the boat )

I'd gut the old transom and redo it with seacast, and then cut and mount the new drivetrain. Can't say I'd imagine any of this is going to be a walk in the park though.

 

[gcboat]

Re: OMC to Merc conversion

Check into an adaptor plate. I know they make them but at the moment I'm at a loss of where to find them. Might check with our friends at IBoats for a start. It will be a whole lot cheaper than a complete transom rebuild unless your transom needs to be redone. Of course in that case, - well, rebuild it.
Just a thought.

 

[Bondo]

Re: OMC to Merc conversion

Ayuh,......

As noted, the condition of your Transom is the deciding factor........

I have been able to use actual fiberglass sections, cut from donor boats,+ Plywood to Fill OMC holes....
Using Epoxy,+ cutting Steps into your work makes a Super Strong conversion,......

That's another little piece of the Puzzle that comes from buying a Donor boat to do these Conversions.........

 

[tashasdaddy]

Re: OMC to Merc conversion

as gc said there use to be an adapter from omc to mercruiser. DonS in the merc/volvo forum would know if still available.

 

[wire2]

Re: OMC to Merc conversion

I'm doing an '84 Glastron SX190, had already fit 3 layers of 5/8 plywood in the hole and cut for the alpha, then discovered the original transom plywood was rotten below the water line, especially around screw holes.
I'll be removing all the old, fabricate an inner wall and doing Seacast. I need to do at least 1 motor mount area also.

 

[tashasdaddy]

Re: OMC to Merc conversion

i found this, it looks like converting from omc to volvo. C & P without the ".
"http://www.boatsunlimitedny.com/products/outdrives1.php"

 

[tashasdaddy]

Re: OMC to Merc conversion

talked to Don about it and the one in the link won't work either on the stinger here's his reply. "That adapter if for Volvo to Volvo or OMC Cobra. Have used it, but it's not for stringers.

The only adapter plate I can find is this one from Merc, but it won't do the Stingers either"