What are you seeing for performance with 5.7

SCOTTZSCOTTZ Member Posts: 5 ✭
in General Boating Discussions
Hi, Guys I'm new here and just purchased a 1997 Rinker 266 with a cracked block.  The boat has a 350 in it and it was my intention of replacing it with another 350 but one of my mechanics feels the performance will stink and is steering me towards a 454.  What are your guys seeing for performance with yours (350 and or 454).  
A little background i have been moving up size wise for years.  My last boat was a Rinker 230 that had a 4.3 in it.  Top speed for me was right around 30-33 mph.  Sold that last fall and found this one a couple weeks ago.  Got a heck of deal on it knowing the engine is blown.  
75% of my time is spent trolling for Walleye (yes I know not exactly a fishing boat) with the other 25% leisure.  Most times there are only my wife and I but once or twice a year we would have 4 to six people on the other boat.  Speed is fun but most of my runs are two miles or less to the fishing spot and most beach days are spent four miles from port.
Just curious what people are actually seeing speed and fuel wise with the two different motors.
Oh yeah its hooked up to a bravo three.
Thanks in advance:)
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Answers

  • Lake_BumLake_Bum Member Posts: 988 ✭✭✭✭
    Check into replacing it with the 350 MAG, instead of the 454.  You'll be MUCH happier with economy, and you'll still have plenty of power, compared to the standard 5.7, especially if you have the Bravo 3 drive. 
    2000 Captiva 232 
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  • Cableguy GregCableguy Greg Member Posts: 5,028 ✭✭✭✭✭
    I would check out the Merc 383 Mag. It is designed to give you big block power in a small block. Someone on the forum dropped one into a 270 and the boat woke up. The big block will treat you well by running at a lower RPM to get the same power. 
    2008 280 Express Cruiser, 6.2MPI, B3, Pittsburgh, PA "Blue Ayes"
    Go Steelers!!!
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  • J3ffJ3ff Member Posts: 4,112 ✭✭✭✭✭
    I'm one person who was forced into a new engine, after comparing the price difference over and over... ended up with a 383mag instead of the 350mag..  now I only owned a working 350 mag for 3 days (really 2.5) so I'm really not sure of the difference, I do know it gets up and goes and no matter how many people on board or how much wind (I took it out till Thanksgiving, there were a LOT of wind storm days) it seems to perform the exact same as far as getting up and going, which I think is the complaint with the 350  (more people or wind and it feels weak)
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  • Cableguy GregCableguy Greg Member Posts: 5,028 ✭✭✭✭✭
    The 383Mag is 350 HP. That would be 100 more ponies over the 5.7L.

    https://www.mercurymarine.com/en/us/engines/inboard-and-sterndrive/remanufacturing/plus-series-bravo-sterndrives/

    2008 280 Express Cruiser, 6.2MPI, B3, Pittsburgh, PA "Blue Ayes"
    Go Steelers!!!
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  • J3ffJ3ff Member Posts: 4,112 ✭✭✭✭✭
    Their blurb is why I went with it. 

    "Same power and more torque than a 454 **** carbureted engine. This torque monster delivers 429 ft-lbs of raw torque at 3800 RPM to launch even the heaviest boats with authority. When equipped with the same marine exhaust headers as found on the 383 Scorpion®, this engine produces 370 HP and 456 ft-lbs of torque—more than a 502 carbureted engine. This is the ideal replacement engine for 454HO and 502 **** carbureted engines that power cruisers, large runabouts, and sport boats. Marine exhaust headers sold separately."
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  • SCOTTZSCOTTZ Member Posts: 5 ✭
    Thanks for the responses.  Does anyone have an idea cruise and top end with a standard 260 HP 350?
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  • duane.mosleyduane.mosley Member Posts: 317 ✭✭✭
    edited January 2017
     i would go with the stroker. if your budget allows, buy a NEW one, not a remanned.  if your budget don't allow a new one, you can have a local engine builder in your area build a stroker for less money, and you will know exactly what's in your engine. ALL of the externals on your existing 5.7 will bolt onto the 383, if you switch to a 454, you will have to buy a complete ready to run engine. then your buying a used engine that you don't know the life left. there is TONS of info out there about 5.7 vs 6.2. i have been racking my brain on what to do with mine but i decided to just go back with my 280hp5.7 in my 06' 250. mine has MPI fuel delivery and getting proper fuel air mixture with the ECM is tricky so i decided to stick with the stock set up. with your 266 most likely being carburetor, you can easily jet it up and adjust the mixture to have a really strong stroked small block.


    i would guess that a standard 5.7 would give you a cruise speed of around 23-26 with a 266 with half tank gas and 2-4 people on good water. that's what a friend of mine was getting with a 94 266 that had the 5.7

    good luck on your decision, if it were me and your budget allowed, go 383 and get the power of a 454 with less weight.
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