Repowering from OMC cobra to Mercruiser

[Crazson34]

I have a 28' Cruisers inc. with twin 5.7 cobras. I'm going to swap to Mercruiser but how does the Merc twins work. Does 1 engine counter rotate like the OMC or is it in the outdrive only? If it's in the drive, is it upper and lower that are different or just the lower? I'm planning on using Alphas to keep prices down. Any info would be helpful. Thank.

 

[Haut Medoc]

Re: Repowering from OMC cobra to Mercruiser

Welcome to iboats......
While there are Merc engines that counter rotate, that is on the inboards (MIE) only......
Mrecruiser Sterndrives (MCM) achieve counter rotation through the drive, specifically through the lower half......
So be careful when buying engines for it, you want two standard rotation ones......​

 

[a70eliminator]

Re: Repowering from OMC cobra to Mercruiser

I'm not help but will be following your progress for I will soon be doing the same thing, hopefully you wont have to do a bunch of work to the transom for the merc to fit. Luckily you have 5.7's mine is a 5.8 Ford and I'm not sure if there is even a coupler for that motor to work with a merc.

 

[Haut Medoc]

Re: Repowering from OMC cobra to Mercruiser

I'm not help but will be following your progress for I will soon be doing the same thing, hopefully you wont have to do a bunch of work to the transom for the merc to fit. Luckily you have 5.7's mine is a 5.8 Ford and I'm not sure if there is even a coupler for that motor to work with a merc.

The old style (round) coupler should work for you.....

 

[Crazson34]

Re: Repowering from OMC cobra to Mercruiser

Is the 888 the outdrives I want to buy? Sorry, I've only owned 1 merc before. The rest were Volvo or OMC. Both expensive parts. Also, I have a standard rotation engine in my boat that's OMC Cobra 5.7. Can I keep the block when I switch to merc?

 

[Lou C]

Re: Repowering from OMC cobra to Mercruiser

You do know that you can switch those Cobras over to a Volvo SX (provided they are Chevy engines) by just changing the pivot housing, shift cable and adding the engine mounted impeller? Yes the Volvos will cost more than an Alpha, but that saves having to pull the engine, and change the complete transom mount, tilt and trim, and power steering over to Merc. After you add it all up with labor, it might not actaully cost much more to go Volvo.

 

[Crazson34]

Re: Repowering from OMC cobra to Mercruiser

Only the port engine is good and I don't know the history of it so I want to refreshen it anyway. We plan to keep the boat and the price of Volvo parts in the long run I believe will cost me more. Also, I live in Arkansas and the last volvo I had, nobody here would work on and parts killed me. Everybody here works on and only sells Mercruiser. If I lived near a big city, maybe I'd consider other options but even in Little Rock, there are no good mechanics or reasonable parts. Thanks though for throwing out options. ANY help is so valuable. Thanks to all for your input, Bobby