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Catalina 30 and 5411 diesel what prop is best for power

Mikem

.
Dec 20, 2009
753
Hunter 466 Bremerton
My daughter has a 1982 tall rig Catalina 30 with the venerable 5411 diesel. It has a two blade Gori 13" x 9" folding prop. After repairing, cleaning ( the 1 5/8" ID riser was down to 1/4") and reinstalling the heat riser the engine does not overheat and it revs up to 2976 rpm at WOT. Rated rpm is 3000. It will do 5.4 kts now at WOT. The boat has a spare two blade fixed Michigan sailor prop 12" x 12". Does anybody have any experience with that prop. I'm sure reverse would be better just wondering about forward performance. There are strong currents here in the PNW...I know a three blade would give me better punch but since this is a spare already on the boat the cost is zero. Thanks, Mike
 
Mar 29, 2017
574
Hunter 30t 9805 littlecreek
The 12x12 will definitely allow boat to rev up to proper rpm's and help it breath which would help with exhaust clogging problems. But hull speed is only 6 knots on Catalina 30 maybe with prop slip you'll get 6.2. Two blade prop? It will sail alot better with smaller 2 blade .
 
May 23, 2004
3,317
I'm in the market as were . Colonial Beach
Hull speed is 6 knots? It is more like 6.7 Knots.

I had the universal M25Xp in my MKii Catalina 30. I could only motor at 5-5.5 knots with the three blade prop.

The problem with the Catalina 30 is the prop clearance. You can only put a smaller prop on it as the 23hp diesel was a good sized engine for the boat.
 

dmax

.
Jul 29, 2018
490
O'Day 35 Buzzards Bay
Actually, the 12x12 will lower your WOT rpm as it is essentially a higher gear. Your boat will go faster at a given rpm vs. the 13x9 (12" for every revolution vs. 9", theoretically) but the engine will be working harder. I think the stock propeller for the C-30 with MX 25 was a 12x9 so I would stick with the Gori since you can just about reach the engine's max rpm. Most likely, with the higher pitch prop will not be able to reach the max rpm, which means you are over=propped and will cause more coking of the exhaust riser. I had a C-30 with a 3-blade prop and 6 knots was hard to achieve under power.
 
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Apr 8, 2010
1,620
Ericson Yachts Olson 34 28400 Portland OR
The OP is reporting a smaller HP diesel than some of the responders seem to be assuming. Given the displacement and full bow sections of that design, it will motor easily up to about 6 kts or a tad more, but would need a lot more HP to get over 6.5. Later versions of that hull were indeed sold with a lot more HP. Prop clearance is certainly another challenge, and the hull was originally designed to work with the A4 30 hp gas engines. While economy was improved with the changeover to diesels, the hull-to-tip limitations of props was always a compromise.
Sometimes you just need to accept compromises in a solid little cruiser. And accept them in every other kind of boat, too! :)
 
Oct 22, 2014
16,087
CAL 35 Cruiser moored EVERETT WA
Based on your statements, I would be pleased with the Gori and plan my cruising/navigation to take advantage of the currents not fighting them.
A properly functioning Gori prop would enhance the sailing of her boat. On a sail boat sailing is the Primary power source. The "good" auxiliary power is provided by the diesel power and prop. As you increase the stuff loading down the boat, your planning has to adjust to the conditions. I note riding North from Bremerton with the tide from Seattle to Port Townsend, you can achieve 7 plus knots (2 knots of current).

Most cruise trips you can time the passage so you do not have to sail/cruise at odd hours (0200 due to tidal current). It is kind of a fun game to plan your cruise both day and time to take advantage of "speed" passages.

And when you get to a problem area - current against you, anchoring and waiting for the current slack is a great time to catch up on sleep missed because you untied the lines at 0400.
 

Mikem

.
Dec 20, 2009
753
Hunter 466 Bremerton
Based on your statements, I would be pleased with the Gori and plan my cruising/navigation to take advantage of the currents not fighting them.
A properly functioning Gori prop would enhance the sailing of her boat. On a sail boat sailing is the Primary power source. The "good" auxiliary power is provided by the diesel power and prop. As you increase the stuff loading down the boat, your planning has to adjust to the conditions. I note riding North from Bremerton with the tide from Seattle to Port Townsend, you can achieve 7 plus knots (2 knots of current).

Most cruise trips you can time the passage so you do not have to sail/cruise at odd hours (0200 due to tidal current). It is kind of a fun game to plan your cruise both day and time to take advantage of "speed" passages.

And when you get to a problem area - current against you, anchoring and waiting for the current slack is a great time to catch up on sleep missed because you untied the lines at 0400.
Yep, currents are something. Christine and I went for sea trials (after the riser repair) a few days ago. Departing from Bremerton Yacht Club we entered Washington narrows and knowing we faced a strong flood we opted to go uphill first that is south under the bridges. Under the Manette bridge and at the cruising Rpm of 2500 our speed over ground slowed to 2.6 kts. As we turned around and headed the 2.3 nm back to the club our speed over ground hit 8.6kts. For grins Christine went WOT and we hit 9.0. Yahoo.
When I transit to Friday Harbor from BYC (about 77nm) in my H466 using currents I have made it in as little as 8 hrs. Always use the currents.
Regarding the feedback, which is greatly appreciated, I am inclined to stick with the Gori. No need to stress the 38 year old raw water cooled 11 hp diesel. Can’t hate 1/3 gal per hour consumption. It is a great boat. Cheers, Mike
 
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