Long distance cruise with Volvo D6-350/Duoprop

[Boracay]

I'm looking at an older 10m fibreglass sedan cruiser with a Volvo D6-350 engine and a duo prop drive. Available fuel is 350 litres.

I want to do long distance cruising with daily distances of 100nm and total trip distances of 2000nm leaving the boat in sea water/marina most of the time.


How suited might this setup be for that sort of cruising and what sort of reliability could I expect?

 

[rsn48]

The boat and engine will do what you want, however the fuel burn on plane can get expensive over long distances.

For long distances, you might want to consider a more traditional trawler with a top speed of 8 knots or so. You will burn less fuel and the diesel engine can take a beating.

 

[Boracay]

Too Cheap?

There are very few traditional trawlers available in Australia, and they are relatively expensive with old engines.


This boat is OK priced and there may be some room to bargain.


I'm estimating 20 litres/hour at cruise (15 knots) so my 2000 nm trip would use about 2600 litres for an estimated cost of $3,500. A displacement boat might have similar numbers.


I'm more concerned about the reliability of an older engine/stern drive.

 

[BruceK]

More info about the boat would help.
A 40 ft full displacement hull boat would not do 15 knots, it would be speed limited by its length. I`m guessing this is either semi displacement(or semi planing),or a planing hull.

Volvo engines have their critics over parts availability and cost, and some complexity of the cooling system. The D6 could be relatively newer. I suspect asked for 15 knots, it would be running hard and use a lot more than 20lph, but I really don`t know.

Stern drive(aka outdrive in USA) has problems from locating the gearbox underwater, maintaining seals so water stays out and oil stays in. The build up of growth on sterndrive units can be monumental. There is greater servicing and maintenance cost for a stern drive compared to shaft drive.

 

[Archhibb]

As a diesel, the D6 should be up to mission with the usual caveat that it’s in good running order. Check out Boatdiesel.com for feedback on the D6’s reliability.

The stern drive is likely the weaker link. The biggest enemy is all the heat generated by the various driveline offsets. I suggest adding a shower rig to cool the drive and it will fare much better.

 

[RCook]

Over 18 years, I did 15 summers of 2-4 months and 2000 to 4000 nm in my 26-foot Bounty with a 260hp VP KAD44P, and 290 duoprop drive. We traveled most of the time at 6.5 knots, getting 4 nm/gallon. At 16-18 knots we got 1.75 nm/gal.

With annual drive lube changes and drive servicing about every three years, I put 6,502 hours on that engine before I sold the boat. Early on we had a drive failure, replaced with a new one at Volvo's expense. Otherwise no major problems.

 

[mcarthur]

I'm estimating 20 litres/hour at cruise (15 knots) so my 2000 nm trip would use about 2600 litres for an estimated cost of $3,500. A displacement boat might have similar numbers.

If the 40' can do 15kn, then think perhaps 60lph if you're lucky, more possibly 80lph. So 2000nm at that speed (which is overdoing it anyway in many conditions) would be about 10,000L for about $15,000.

Slow doooooowwwwnnnn to 7kn and you may be about 10lph.

 

[Jeff F]

I'm estimating 20 litres/hour at cruise (15 knots) so my 2000 nm trip would use about 2600 litres for an estimated cost of $3,500. A displacement boat might have similar numbers.

I think your estimate is wildly optimistic. You may not have much more than 100 miles of range at that speed.