Is this set up even possible to run?

Discussion in 'Props' started by Christopher Dodigovic, Jun 23, 2021.

  1. Christopher Dodigovic
    Joined: Jun 2021
    Posts: 1
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    Location: 89102

    Christopher Dodigovic New Member

    Hello everyone. new here. Thanks for allowing me in. I have a 84 Sea Ray 245 sundancer. Mercruiser 260hp v8, had a sterndrive engineering alpha1 gen1, is 4650lbs dry.

    When I bought the boat I was told sterndrive was just rebuilt which it was and had receipts to prove. But somewhere, somehow case cracked and all the oil leaked out. Dummy me, before taking it out I did not check the oil level considering paperwork was pretty new. Well it was out of oil since it sat so long and first outting toasted it. along with boat he threw in another sterndrive, maybe he knew? An MC1 or R type i have seen it called. But this drive has a stamp of 1.84 gear ratio which from research tells me its for a v6 OR A 4cyl depending on year? So thats a little confusing to start.
    Now my drive i am guessing was a 1.5 or 1.47 gear ratio. It has a 16 x 14p propeller. But stock with the 260 drive was a 15 3/34 x 16 according to the mercury customer service guys. So i now know i can't run that on either set up.
    so my question is i have read of guys running this gear ratio with a v8 by just changing the prop. My question is can I run this actual set up of thev8 with the mc1 and a higher pitch prop? From reading i have done most say 3 to 5" increase in pitch has done the trick. So from stock that would put me in the range of a 19 or 21 pitch. Can I run it? And if so what prop? Thanks in advance.

    Oh and the alpha 1 is going to get redone but on a massive waiting list. So want to run the boat while waiting.
  2. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    I would think, assuming the drive will bolt straight on, that just using the prop on that drive, it should get you on plane, but speed will be restricted, if you try high pitch props to get the same performance, you could end up loading up the smaller gears too much, resulting in expensive noises. It gets down to whether that drive ratio, with that prop, is sufficient to plane the boat, the drive doesn't know what engine is turning it, it just has to turn at a high enough rate.
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
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    Location: Australia

    Mr Efficiency Senior Member

    I recall having a boat with a V6 outboard, and the gearcase had, just like yours, an oil leak, in between getting it fixed, I slotted on a gearcase off a V4 engine of the same brand, fitted perfectly, I didn't change the prop (retained the one that was on the V4, which was not a terribly high pitch), the thing worked to get the boat on a clean plane, but running more revs than ideal, but acceptable when backed off to a clean plane. That cannot hurt the drive. Going up in pitch probably would have.
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