SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Beneteau (http://www.sailnet.com/forums/beneteau/)
-   -   cruising speed beneteau 40 (http://www.sailnet.com/forums/beneteau/46220-cruising-speed-beneteau-40-a.html)

ronikokernoot 08-19-2008 12:59 PM

cruising speed beneteau 40
 
Hi I am going to buy a Beneteau 40 from 1996 with a Yanmar engine.
The boat has been in the water for more then a year.It has a lot of Barnacles
also on the prop.While sailing it got to 3000 rpm and a speed of 5.5 knots to 6 knots.
What should be my maximum speed and my cruising speed?
Should a 12 year old engine perform like a new one and what is the life expectancy of this sort of engine?

All advice is appreciated.

Roni

Zanshin 08-19-2008 01:06 PM

The LWL of the Beneteau 40 is 33 11/12 feet, so your hull speed is 7.8 knots.

You are probably getting a lot of drag off the hull and perhaps even cavitation from the prop. You should be getting more RPM and speed from the engine but that could be due to the dirty hull. More importantly, clean and smooth the prop.

negrini 08-29-2008 01:04 AM

Regarding performance, Zanshin is correct ! Age has minimal effect to the engine, specially these reliables Yanmars. Hours, of usage gives you some reference, but MAINTENANCE is the key here. Properly maintened, these engines goes well beyond 10,000 hours of service. A visual inspection will revel PO care on boat, including engine, but have it surveyed for a consistent check.

hellosailor 08-29-2008 02:01 PM

Roni, with enough growth of the prop, even if the hull is clean you can reach full throttle and have zero forward speed. On pretty much any boat.

If you have growth ("a good beard") on the hull and some on the prop, hitting 6 knots would be quite good actually. It can easily cut 1-2 knots off the speed of a boat.

Engine life and performance is a whole realm of "maybe". A good diesel, properly maintained and operated, should get 5,000-10,000 hours on it before it needs an overhaul. Not years--but hours of operation. If it is abused, the cylinders can get carbon deposits, the injectors can be ruined, and acid and sludge in the oil can ruin bearings while the cylinder walls and rings have rusted--all in the span of two or three years with near-zero use and zero maintenance.

Some maintenance is seasonal (before/after layup) while other things are base don hours of run time. If the boat doesn't have an hour meter ("Hobbs" meter) that tracks the hours the engine is actually running, they are not hard to add, and they give you a real count instead of guessing.

There's really no way to be sure, except to have a diesel mechanic take a look at it. He can pull the injectors, look inside the cylinders with a borescope (without remoing the head), test and if necessary overhaul the injectors, run an oil sample analysis, and give you specific answers about how healthy the engine is. That's probably going to cost you $300 or so, unless he hits the key and says "Gee, sounds perfect!" and tells you to skip the rest.

If you are unfamiliar with the engine, and diesels in general, it can pay to simply get a referall for a GOOD mechanic (which isn't always easy) and then have him come out for a couple of hours to inspect the engine AND to show you what has to be done to keep it running properly, how to bleed the fuel system, and so on. A much better investment than a tow or AAA membership.<G>

sailortjk1 08-29-2008 03:21 PM

Quote:

Originally Posted by hellosailor (Post 360405)
Roni, with enough growth of the prop, even if the hull is clean you can reach full throttle and have zero forward speed. On pretty much any boat.

If you have growth ("a good beard") on the hull and some on the prop, hitting 6 knots would be quite good actually. It can easily cut 1-2 knots off the speed of a boat.

Its amazing how much just a little growth can slow you down, Just like HS said. Even a small bit of seeweed on your prop will significantly alter the proformance of your boat.


All times are GMT -4. The time now is 05:06 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012