Princess 35 Flybridge cruise speed and RPM

[Norloch2]

Hello again everyone,

 

As mentioned in other posts, I recently purchased an '89 Princess 35 Flybridge with Volvo TAMD-41A engines. I absolutely love the boat, it's sea-keeping abilities, size, comfort and safety.

 

This is my first yacht with Diesel engines. Because of that all my experience with gasoline engines doesn't help me much. I'm learning as much as I can but would appreciate input from others about cruise speeds and RPMs. Engine longevity is my primary concern.... Not speed.

 

From what I've read on-line, it is suggested that the 'cruise rpm' for these engines is about 300-400 revs below max. The Volvos top out at about 3700 rpm.... So that would suggest cruising with the TAMD-41A's at 3300-3400 rpm. For an engine that's 27 years old, that seems pretty high to me.

 

While I've only had the boat a short time, I typically run her between 1500-2500 rpm and achieve speeds of between 8 to12 knots. I'm in fresh water and the boat is typically loaded (heavy).

 

Was hoping other Princess 35 owners and other Volvo TAMD-41A engine owners would jump in on this string and let me know what they run at for rpm and speed.

 

Norloch2

[Bårdp]

Volvo TAMD-41:

Max RPM 3900

Crusing 3500 RPM

[Jori]

Correction on Max RPM:

 

41A 3800 RPM

41B 3900 RPM

 

I loocked it up on this page: http://www.marinfakta.se/index.php?sida=ad41

 

You will find a table that you easily can read information from there

 

For cruicing you must trust your experience. I'm  normally cruicing between 3100-3300 RPM, have to 41B. Reason is that boat travel nicely in this area, and from my experience it will not use so much fuel compared with cruicing on 3500RPM. However below 3000RPM the boat start falling out of cruicing mode and work really hard. So in practice for my boat the RPM area between 2200-2900 is useless. You will find the ideal area after some use of the boat. I have a Princess 346/366 for information.