Cruise/WOT speed on 30' Weekender ??

Discussion in 'Classic Sea Rays' started by Captain Crispy, Aug 15, 2009.

  1. Captain Crispy

    Captain Crispy Member

    163
    Nov 24, 2007
    Virginia
    33' 1987 Sportfisher II
    hamsters...scurrying little hamsters...
    What cruise & WOT speeds can I expect for a 30' 1980's Weekender ?
    Assume clean bottom and running gear, twin carbed 350's in good condition, cruising at 3000-3200 RPM.

    Fuel economy ?
     
  2. berth control

    berth control New Member

    886
    Nov 16, 2008
    Saugatuck, MI
    1985 270 Sundancer
    3.7 liter Mercruisers
    I would expect cruise around 20 to 25 mph and WOT around 30 to 35. Maybe more, but not much. Fuel economy around 1.3 mpg.
     
  3. Captain Crispy

    Captain Crispy Member

    163
    Nov 24, 2007
    Virginia
    33' 1987 Sportfisher II
    hamsters...scurrying little hamsters...
    Is that from actual experience ?
     
  4. Sundancer

    Sundancer Active Member

    Jul 20, 2005
    Prosser, WA
    30 year old CLASSIC 300 DA, towed almost anywhere behind the Duramax Duallie Crew Cab.
    16 cyl, 700 cu. in./Alpha I's
    Fuel ECONOMY is kind of an oxymoron with boats!! I estimate closer to 1 mpg, with my twin 350 powered Sundancer. I have stern drives. At around 3200 rpm I'm running about 25 to 27 mph depending on load and conditions.
     
  5. jimmy

    jimmy New Member

    14
    Sep 6, 2009
    sarnia
    300 searay express cruiser
    twin 350 mercruisers
    i,ve got a 1988 30 ft weekender, 3100 rpms runs mine at 28mph, fairly quick for a boat this size and age.350,s push along good.
     
  6. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    My 300 did 24 knots with full fuel, water and waste. As the fuel burned off it would register 26-28 knots at 3100 rpm (wot was 4400). That was a new boat with fresh engines.
     
  7. Sundancer

    Sundancer Active Member

    Jul 20, 2005
    Prosser, WA
    30 year old CLASSIC 300 DA, towed almost anywhere behind the Duramax Duallie Crew Cab.
    16 cyl, 700 cu. in./Alpha I's
    Inboards or Alpha's? Most Weekenders had the inboards, but some may have had the Alpha's. Unless noted in the comparison numbers above, there isn't anything to compare! :huh:
     
  8. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    Mine was straight inboards. The only way to go in my view as the inboards require less upkeep and better balance.
     
  9. Captain Crispy

    Captain Crispy Member

    163
    Nov 24, 2007
    Virginia
    33' 1987 Sportfisher II
    hamsters...scurrying little hamsters...

    All 30' Weekenders were inboards. With the Alphas, they added the under-helm berth and "POOF" its a Sundancer.
     
  10. JAndrewG

    JAndrewG Member

    158
    Jul 23, 2007
    Brownsville Washington (Seattle area)
    340EC
    330 HP Mercruiser inboards
    Correct. I bought a left over new 1986 300WE in 1987. All Weekenders of this newer style hull had inboards (starting in '85 I think). Most had 350 cu.in./ 260 hp small blocks, but some later boats (this hull was used through '89) had 454 cu.in./340 hp big block motors. A friend bought an '89 300WE new that had them. It was interesting to run with him. At any cruise speed his boat was running about 400 rpm less than mine. If he was loafing along at 3200 rpm, I had to run 3600 to keep up. But it was barely faster at WOT. These boats seem to begin to push the bow down (due to the fixed angle of the inboard shafts), which was why, I thought, that top speed wasn't much different.

    My 300 ran about 25 knots/28-29 mph at 3100-3200 rpm, and burned less than 30 gph, giving about 1 mpg.
     
  11. Sundancer

    Sundancer Active Member

    Jul 20, 2005
    Prosser, WA
    30 year old CLASSIC 300 DA, towed almost anywhere behind the Duramax Duallie Crew Cab.
    16 cyl, 700 cu. in./Alpha I's
    So the engines facing forward with a shaft to the Alpha's is not normal? A friend has an 88 that is this way. It's a weekender and it rides better than mine, but he has the Alpha's!
     
  12. Captain Crispy

    Captain Crispy Member

    163
    Nov 24, 2007
    Virginia
    33' 1987 Sportfisher II
    hamsters...scurrying little hamsters...

    Is it the 300 Weekender ? Smaller Weekenders did have I/O's, but every reference I have found through Sea Ray and other sources indicates that all 1980's 300 Weekenders had inboards with straight shafts.

    It sounds like you are describing a jackshaft. I have never heard of any 1980's Sea Rays with Jackshafts, so perhaps your friend has a custom installation.
     
  13. Mike Gazdik

    Mike Gazdik New Member

    11
    Aug 26, 2009
    Vermilion, Ohio
    1989 300 Weekender
    twin 350 inboards
    I am very new to this, have had a 89 30' Weekender for all of 1 week now! (350's)

    Mine is cruising around 28mph at 3200ish. My tachs are a little sloppy sometimes. I have backed it down to around 3000rpm and can still cruise around 21mph. I have not topped it out, except during the survey. Think it was around 4200rpm and maybe 35mph if I can remember.(again, not certain on WOT though)

    Cannot give you fuel consumption estimates yet. It doesn't seem too bad though.
     

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