Yanmar 4JH3-DTE or 4LHA-DTP for 31' boat?

[tomi]

Hi,

I am considering in buying a 9.5m (31 feet) planing boat, 4500 kgs of weigth. You can see the boat at:
http://www.sas-vektor.hr/prod03.htm
It has direct shaft drive.
Tests for 2x Yanmar 4JH3-DTE show the following speed at RPMs:
800rpm: 3kts, 2000:7.4, 2600:12.5 (planing limit), 3500:18.8 (cruising speed), 3900:23.
Manufacturer also offers 2x Yanmar 4LHA-DTP for additional 10k$.
Which engine package should I take? Do you think 4JH3s are proper for planing boat? Are they too small for this particular boat? I am not interested in speed so much, but wouldn't want to push the smaller engines all the time.

Thnx.
Tomi

[bilgeboy]

There is a conventional wisdom that suggests you get as large an engine as you can afford. Its always a drag wanting to go faster when you cannot. When the weather turns sour, or you want to stay at your great fishing spot another 20 minutes, but you have to be home at a certain time, etc, etc.

If you have more specific technical question, I suggest you try at boatdiesel.net. A good question will get experienced advice.

For most of us, 10K is nothing to sneeze at, though...ah...:o ...choo.

Mike

[tomi]

Sorry, have been trying to see boatdiesel.com for over a week now, but in IE and Firefox browsers I just get blank page (no error!). Is there any trick or special URL to get to boatdiesel.com?
While boatdiesel.net requires username and password to get to the main homepage.
Please help!
Tomi

[bilgeboy]

Sorry about the .net vs .com confusion. I don't know why you are having a problem.

Its $25 US to register, but you don't have to do that. Give it a try.

Mike

[tomi]

Tried to browse to boatdiesel.net, but as soon as I place URL and press go, browser requires (IE or Firefox) username and password. So I cannot get to the homepage either.
Tomi

[kapnD]

The speeds/rpm posted by any manufacturer are usually quite unrelated to real world numbers. I would definately opt for the higher horsepower.
Nice looking sled!