New engine for Westerly Corsair

[Cspirit]

Some advice please. The current and soon to be removed engine is a Volvo 2003 with a two bladed propellor. I will probably go for a new Beta engine but I need to decide whether to go for a 30hp or a 35. My thinking is that the smaller engine will be cheaper, smaller and lighter and at cruising revs will probably be working harder (which I understand is better for the engine). On the other hand, the larger engine, being 4 cylinder, will be quieter and will have more power in reserve. The current engine seems to provide enough power (at a 28 notional hp). Any thoughts?

Also, it has been suggested to me that a 3 blade prop will significantly improve engine performance in exchange for a small loss in sailing speed. Again, any thoughts most welcome.

 

[Tranona]

Go for the 35 and a 3 bladed prop (the displacement of the boat is quite high at 6.5 tons and the 35 is a lower revving engine). However drag will be greater than a 2 blade but motoring performance better. If you can afford it then a Featherstream 3 blade feathering prop will give you the best of sailing and motoring performance.

 

[VicS]

Go for the 35 and a 3 bladed prop. However drag will be greater than a 2 blade but motoring performance better. If you can afford it then a Featherstream 3 blade feathering prop will give you the best of sailing and motoring performance.

Alternatively if the existing 28 hp is powerful enough go for a 30hp and put the money saved compared with a 35 towards the cost of a folding prop.

 

[Tranona]

Alternatively if the existing 28 hp is powerful enough go for a 30hp and put the money saved compared with a 35 towards the cost of a folding prop.

The original 28 was marginal and Volvo did not have a 35 or 40 at the time and the option was the turbo 43 which was OTT for the boat.

 

[sailorman]

get an engine that is rated @ 3000RPM Westerbeke or that Beta 35 or even the Nanni 38 ( i have the same engine 37.5 hp )

 

[pvb]

get an engine that is rated @ 3000RPM Westerbeke or that Beta 35 or even the Nanni 38 ( i have the same engine 37.5 hp )

Sailorman has a point - the Beta 30 gives 30hp at 3600rpm, which is fairly fast for a yacht engine. The Beta 35 gives 35hp at only 2800rpm, which is rather more relaxed.

Having owned a Corsair, I'd agree that the original engine is a bit marginal, and I'd go for something in the region of 35hp as a replacement.

 

[lw395]

A folding prop or feathering will give a useful perfromance increase when sailing.
I think I've only sailed with one Beta 30, that seemed very very smooth, as a 3 cylinder engine should be.
But I guess mounts and so forth come into it.

Cost no object, I would want the bigger motor, flexible mounts, UJ's in the prop shaft and a feathering prop....