Yanmar BY 260

[Hey Doc Senior Member Find all posts View Profile Close Hey Doc]

Just recieved an email with a video link on the new Yanmar 260. It looks to be an impressive engine. The url is

http://www.boattest.com/videos_homep...ip=yanmar_260z

If you have a second, copy and past the url link into your browser to see the video.

I currently have common rail volvos, which are great engines. I just thought I'd put up the link, as I am really impressed with the yanmar.

[Patriot Senior Member Find all posts View Profile Close Patriot]

My only concern is how small the engine is. Displacement is only 183 ci. Compare that to the mechanical 4LH (240 hp) at 211 ci or the mechanical 6LP series (260-315 HP) at 254 ci. Although Yanmar has always been on the small side of the HP/Displacement ratio, this is really pushing it IMO. Time will tell.

[JuliaGCC25 Member Find all posts View Profile Close JuliaGCC25]

Yanmar

I feel that as with any engine the higher rev's, increased cylinder pressure and lighter materials all translate into shorter life. This includes the 315 in my 25.

I guess the question is how much shorter. Even if you put 500 hours per year on your engines (well more than the average boater) you will have the engines operable for quite a while.

Could this be how Yanmar figures it too?

[Patriot Senior Member Find all posts View Profile Close Patriot]

The old adage about diesel displacement being less than ideal below 1 cubic inch per horsepower has surely been proved to be old school theory versus engineering reality. Both Yanmar and Volvo continue to push the envelope as the demand for higher hp, smaller weight diesels continues. Just how far that ratio can be pushed without adversely affecting engine life is yet to be known. The 6LP you have has a ratio of 1.2 HP/cubic inch, the new 6BY moves to 1.4 which is right about in line with the new Volvo D-4 making 310 HP. To put that in perspective, the Cummins 5.9, 330 HP makes .9 HP/cubic inch.

The cooling systems become super critical with these engines as those coolers have also become smaller in size. The cleanliness of coolers becomes the number 2 maintenance concern on a Yanmar right behind oil changes. Rest assured your engine will last a long time with excellent maintenance. I fished on a friends charter boat in October with a Yanmar
6LP showing 7200 hours on the hour meter, he installed it in 2001. His only failure to date has been a blown tranny (Hurth 630) due to, you guessed it a severely clogged transmission oil cooler. With that kind of hour usage water pump replacement becomes a yearly task and cooler cleaning is critical. I have also found the Yanmar to eat cooler zincs pretty fast so keep a close eye on them as well.