Prop advice

[jackho]

Need some feedback. Anyone use a 3 blade Brunton Autoprop with Volvo saildrive
(27HP). Also forgetting price difference does the 3 blade have many advantages vs the 2 blade folding.
What would the forminites choice be and any comparison to the Gori.
Boat 37ft , 7 ton, hi freeboard, 12ft beam.
Going astern and turning into the wind presently very difficult (sometimes impossible) !!!
All opinions welcome.
Thanks in anticipation.

 

[Skyva_2]

Can't compare, but we fitted a Gori 3 blade this year and the result is highly satisfactory for both sailing and motoring - forward and reverse. I have heard the Volvo prop combination eats anodes but maybe that is just hearsay.

 

[Seanick]

Try a Kiwi Prop. No corrosion s/s hub, plastic blades, which also align with the water flow, so less drag than most. Good ahead and astern, with no 'clonk'. Under a grand too!
Sound like you could do with some more HP though, about 50 should do it.

 

[boatmike]

It will simply transform your boat. Standard 2 blade folders are notoriously inefficient. the Goris, Kiwis etc are an improvement but the Autoprop is considerably better. In fact under some conditions they are more efficient than a fixed blade prop as they adjust to the perfect pitch. Efficiency in reverse is almost as good as forward where folders are miserably bad. I also think the post suggesting a larger engine is wrong. 27 HP is plenty for the boat you describe but you are not using it all as your prop is so inefficient.
My cat is 37 ft and weighs 6 tons with water and stores aboard. I have a main engine on a lifting leg with a conventional prop and a "wing engine" of only 10HP with a volvo saildrive. With a volvo 2 blader the little wing engine would struggle to drive te boat at 3 knots in flat calm conditions and reverse was a joke. With the brunton (2 blader in my case as it is small) it drives the boat at 5 knots and is great in reverse too. The biggest added attraction though is when motor sailing. Because it senses the pitch and goes "course" I can use the little 10HP to boost 3 knots sailing to over 6 knots with only 10HP. Magic! With a conventional folder it had no effect whatsoever! Definitely buy one and join the believers club!

 

[Sequoiah1]

All the folding props are much of a muchness Gori is great for low drag and is better engineered than most. We fitted J prop to a 27HP Volvo sail drive this year, the only thing we need to do is adjust the pitch when open as at the moment its a bit fine (job for the winter). Excellent otherwise, more power, more kick astern and the best thing is no noise when we are sailing with the prop locked closed. The boat is 38' loa, 12' beam and 6'5 draft approx ten tons deadweight and you dont need a bigger engine! Sounds to me that if you cant turn into the wind you have a bigger problem though?