best prop for 322?

Jun 1, 2007
265
O'Day 322 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?
 
May 17, 2004
5,026
Beneteau Oceanis 37 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.)
 
Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
Approx. 5 kts is darn good! What rpms are you running her at? You might be overtaxing the engine.
 
Jun 1, 2007
265
O'Day 322 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.
 
Jan 7, 2011
4,723
Oday 322 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
 
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May 24, 2004
7,129
CC 30 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.
 
Jan 27, 2008
3,045
ODay 35 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
 

DLB

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Aug 21, 2016
20
Oday 322 St Clair Shores
Our fixed prop run s our 322 at about 5.5 at 2800 rpm's in calm water.
 
Feb 22, 2010
70
Oday 322 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.
 
Jun 1, 2007
265
O'Day 322 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.