Speaking of Diesels

[davidagage]

The orginal Spirit was designed with no motor, later on in life she had a small diesel installed because to race Fastnet, she had to have aux power, Black Spirit was designed with an MD1 Volvo, (5 bhp @ 2K rpms) which is long since gone.

With that in mind, what would you put into a 33' long, 8' beam, 13K+ pound boat. I am thinking around 25 hp? Yanmar, Beta, Nanni....

All opinions are welcome.

Thanks,

DG

[Thad]

I put a Westerbeke 12C two, 12hp, in SEA HARMONY, replacing an MD1B, 10hp. I'm happy. She does well with it. Very similar numbers on the boat, 4" narrower, probably 1 ton lighter. 25 hp would be interesting but tempt you to use more fuel and might test available space.

[paladin]

Beta 10.....90 kilos....

[Pacific Woody]

A year and a bit ago I replaced a 35 year old Volvo MD11C with a new Yanmar 3YM20. 36'LOA, 9'6beam, 12,600 lbs. It pushes me at 7.5kn at 2,600 rpm in calm water but when fighting 30kn wind and 4-5' seas I average about 4kn. Great fuel mileage and at 266 lbs it is 200 lbs lighter than the old Volvo.

[Todd D]

What is your intended use of the engine? If you just want something to get in and out of the harbor you can get away with 15 hp (approximate maximum speed of 5.5 knots on flat water). If you are planning to make longer trips that might involve motoring for hours at a time, then you want around 25-30 hp. 25 hp would let you run at 6 knots all day and 30 would let you get to 6.5 knots.