Newport 30-3 max propeller size?

Aug 16, 2018
82
Newport 30-mkIII Baltimore
I'm looking to replace both engine and prop on my N30. Does anyone know the max prop size that will fit this boat? I've found options of props of 12 - 14 inch, but I'm worried the largest won't fit. The boat is in the water so I have no way of measuring, and when I pull it out it's too late!
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
Need to know the engine model and hp, shaft size, transimission model and gear ration and type of prop (2, o r 3 blade fixed, feathering, folding) and max budget for a prop. Alos have your diver check measurment of the clearance between shaft and hull. Then contact a propeller supplier for a quote on one sized for your engine/transmission.
 
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Aug 16, 2018
82
Newport 30-mkIII Baltimore
Need to know the engine model and hp, shaft size, transimission model and gear ration and type of prop (2, o r 3 blade fixed, feathering, folding) and max budget for a prop. Alos have your diver check measurment of the clearance between shaft and hull. Then contact a propeller supplier for a quote on one sized for your engine/transmission.
Thanks. Yes I've talked to Beta about the engine, and they offer gear ratio of 2:1, or 2.6:1. Then got quote on Campbell sailor 3-blade prop, which specified either 12" or 14" for those ratios. My issue is I'd like the larger prop, but I think it might be too big. I have one photo of the boat in the sling. It's hard to tell, but looks tight with current prop which I think is 12".. I'm not sure, but 14" sounds big on a 30 footer?

Having someone dive might be the only way to figure it out for sure, but is a hassle/expense I'd like to avoid.

Ultimately going with a 12" like is on now is the safest choice. And considering pretty mild current, tides etc here on the (upper) Chesapeake should be plenty fine. My marina is on a calm river, with an easy entrance, I rarely ever need much thrust (ditto for the areas I go to)
 
Aug 16, 2018
82
Newport 30-mkIII Baltimore
Campbell sailor 3-blade propeller.............that is what I installed on all my sailboats. This guy installed a 12 inch diameter x 11 inch pitch on a 7/8" diameter shaft propeller on his 1976 Newport 30 Captain Curran's sailing blog: How to replace a propeller on a sailboat. Below are photos showing the propeller to hull clearance on his Newport 30.

View attachment 200813
Thanks! Found some other photos of N30-2s too, where the 12" looks very close to the boat, and one 13" I think? There some difference between mk2 and 3, but I don't think that much? That's what leads me to not bother with the hassle of trying a 14.

If it doesn't work I've wasted $500+ on a prop I can't use!
If I get a 12"? Marginally less thrust, but still more than I have now (which is fine)? Bit less efficient? (for my minor motoring.. lol).
No, I don't think it's worth it.
thanks
 

Ward H

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Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
I wouldn't order a new prop until I had decided on the new engine, transmission ratio and had the shaft to hull measurement. Sounds like you have too many variables at this point to decide on the proper size and pitch of a new prop.
If it's too costly to have the boat on the hard for the duration it takes to order and receive the new prop, props can be changed while a boat is in the water. Maybe that is an option?
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Knowing your measurements is the best way to approach this project to get the optimum results. :plus: with @Ward H .

You definitely need the shaft size and taper, engine data, transmission ratio, and left or right hand turn, before you order the prop. This data determines the pitch and the proper shaft hole for the prop. You can select the 12" which looks better in the images above. 14" would look to close and either hit the bottom of the boat or cavitate. Both are a no no..

You will get plenty of thrust from a 3 bladed CampbellSailor prop built by WestbyNorth BC Canada.
The WestbyNorth prop took about 6 weeks to be cast, milled and shipped when I ordered mine. I suspect it will be longer under the current conditions.

Love my prop.
1010FC32-94A8-4C6B-B564-E0A1D6B4EDA1.jpeg 2922CDBE-C1D8-486B-9CB7-A30D78BF72B0.jpeg
 
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Aug 16, 2018
82
Newport 30-mkIII Baltimore
I wouldn't order a new prop until I had decided on the new engine, transmission ratio and had the shaft to hull measurement. Sounds like you have too many variables at this point to decide on the proper size and pitch of a new prop.
If it's too costly to have the boat on the hard for the duration it takes to order and receive the new prop, props can be changed while a boat is in the water. Maybe that is an option?
THanks. I've considered talking to the yard and have them pull the boat and store it on the hard a little while before. But except for measuring the prop it's not necessary so not really worth it.

The issues is the ordering the engine and prop both depend on each other. I can choose either 2:1 or 2.6:1 transmission ratio, which then dictate the prop size, 12 or 14. So I'm not ordering a prop yet, I'll get all the measurements (except prop to hull distance..). But I do need to choose my transmission ratio now!

@jssailem btw westbynorth in a prop quote said 10-15 days to manufacture. Kinda surprised, seems short.. *shrug. I have a few months before I pull it to repower, but I'll definitely order asap!