Registered users don't see ads

best prop for 322?

Discussion in 'Bigger Boats' started by Mickstr, Sep 16, 2017. Add this thread to a FAQ

  1. Mickstr

    Mickstr

    Joined Jun 1, 2007
    117 posts, 6 likes
    O'Day 322
    US Mt.Sinai
    322 current/former owners, or anyone with an informed opinion.. I have a folding prop on my 322 of unknown size/pitch, which I'll verify when I haul her in a few weeks. I don't like that I can only count on 4.8-5.3 kts under power. I'm wondering if I got a different prop (fixed? 2 blade? 3 blade?) could I get a consistent 5.6-6.2 ish speed?

    I know the 322 is underpowered with the 2GM20F, and I know my hull speed is ~6.9 kts, but I'm hoping to squeeze another knot out if I can.

    Anyone have some experience here?
     


  2. Davidasailor26

    Davidasailor26

    Joined May 17, 2004
    907 posts, 103 likes
    Beneteau Oceanis 37 LE
    US Havre de Grace
    Do you know the condition of the bottom, and how many RPMs do you get at full throttle and cruising speed? (The problem could be the prop, but it's worth checking other possibilities too.)
     


  3. AlastairLC

    AlastairLC

    Joined Jan 2, 2017
    110 posts, 25 likes
    O'Day 322
    US Scottsdale, AZ Lake Pleasant
    Approx. 5 kts is darn good! What rpms are you running her at? You might be overtaxing the engine.
     


  4. Mickstr

    Mickstr

    Joined Jun 1, 2007
    117 posts, 6 likes
    O'Day 322
    US Mt.Sinai
    Sorry. should have added more info. I cruise at about 2600 rpm, and I hired a diver to clean the bottom. That got me from 4 kts to ~5. But, no more.
     


  5. Tally Ho

    Tally Ho

    Joined Jan 7, 2011
    828 posts, 79 likes
    Oday 322
    US East Chicago, IN
    I have a 14" 2-blade Campbell Sailor on my O322. I am on Lake Michigan, so no currents or tides to deal with. I can get 6+ knots out of my 2GM20F at somewhere around 2500-2800 RPM's.

    Greg
     


    Mickstr likes this.
  6. Benny17441

    Benny17441

    Joined May 24, 2004
    5,209 posts, 255 likes
    CC 30
    US South Florida
    I think underpowered is the key word. How much weight have you added to the dry weight of the boat? Like mentioned previously the condition of the bottom of the hull is critical as a fouled hull with sea growth can induce significant drag. The reason I quote underpowered is because our h320 has the same engine and it also seems we can only count on 4.5 to 5.3 knots. A GPS reading gives speed over sea bottom and does not take into account wind and currents which might slow or speed the boat depending on their strength and direction. Now under sail we can hit and sustain 6.5 to 6.8 in a stiff breeze. We use our speed under sail as an indicator for the condition of the bottom.
     


  7. jibes138

    jibes138

    Joined Jan 27, 2008
    2,717 posts, 82 likes
    ODay 35
    US Beaufort, NC
    Think in terms of thrust at a given RPM versus engine power. It is the "system" power you are after. Currents and wind effect your speed so you need to consider both as well as bottom condition. It sounds like your prop is under pitched so you aren't getting enough thrust at your cruising RPM's. Run a test, take the boat out and crank it to wide open throttle (WOT). See if the engine meets the maximum RPM spec at wide open. If it over rev's before throttle is wide open the pitch is too low on your prop. If you can't achieve full RPM's then the prop is over pitched. I can't comment on folding props but fixed props can be adjusted by a propeller shop about 2 inches of pitch that will change your RPM's about 200 per inch of pitch. Once your prop and engine are matched for your boat you should be able to cruise at about 80% of maximum engine RPM's at whatever speed that provides. http://www.inland-marine.com/PROPPITCH101.html
     


  8. DLB

    DLB

    Joined Aug 21, 2016
    20 posts, 0 likes
    Oday 322
    US Lake St Clair St Clair Shores
    Our fixed prop run s our 322 at about 5.5 at 2800 rpm's in calm water.
     


  9. AndreNJ11

    AndreNJ11

    Joined Feb 22, 2010
    21 posts, 1 likes
    Oday 322
    US Delaware River
    I have a Michigan Sailor 2 blade prop, 14 diameter by 14 pitch. Probably the same prop Greg has on Tally Ho. I get 6.1 kts at 2500 -2600 at the beginning of the season. By the end of the season, it is is down to 5.7 or so due to slime on the hull.
    The 14x14 came with the boat. I might be over-prop'ed somewhat because I cannot get over 2900 RPM, but there may be other factors (throttle cable limitation, etc. I have not tested no load max rpm with the throttle cable off, I can't get 3600 no-load with the throttle cable attached, so the throttle cable length may be limiting max RPM. I am not ready to blame the prop Yet.)

    Anyway, the boat will do 6 kts with the 2GM20F.
     


  10. Mickstr

    Mickstr

    Joined Jun 1, 2007
    117 posts, 6 likes
    O'Day 322
    US Mt.Sinai
    Thanks all. Now that the boat is hauled, I've found I have a Max Prop feathering 2 blade 15" propeller. At the end of the season I conducted WOT tests, and got the rated 3400 at no load, and about 3350 or so under load. No smoke issues at WOT either (yay!). The prop has adjustable pitch settings, for which you have to remove it. I plan on taking the prop off and bringing to a local shop for advice. I keep hearing that the Campbell Sailor 3 blade fixed prop is the cats meow, but not sure if I can swing one this off-season.. Will get some professional advice and post what they recommend.
     



Mainsail covers
Pre-patterned mainsail covers to fit your boat
20% OFF innovative boat clips!
FixClip holds laundry, tools, anything to rails and life lines even in strong winds.
Turn any toilet into a Raritan for a fraction of the cost
The Raritan LBA matches your existing bowl with the pump/plumbing of a PHII or PHC. save!
Too hot? INSTANT BIMINI ESTIMATES
Low prices, custom fit, no-wait estimates