WOT max revs...

[Ripster]

Got a pair of KAMd300s on c33ft FB Prestige 32. Just launched her back last week and on the way back to the Berth, decided to give it some beans. At WOT she pulled 30k (SOG) at 4000rpm! I did not expect her to rev that high. Both engines were equal revs. The boat had 2 crew on the FB, 60% full fuel tanks and all the usual clobber - liferaft etc. Just had the bronze props refurbed and she has a very clean bum (just done). Also fitted disc type rope cutters. Does this sound about right - speed to RPM?... if not my thoughts were either poorly pitched/repaired props (from the refurb) or incorrect pitch altogether! or is it the damn rope cutters!

 

[volvopaul]

3900 from memory , best to check your book but the revs counters are not 100% accurate anyway so I wouldnt worry about it too much.

 

[Ripster]

Thanks Paul - didn't realise they revved that high! Glad it sounds about right.

 

[Nautibusiness]

With the KAMD300's we used to typically get 3850 and about 28.5kts over a two way measured mile from new boats during the PDi sea trial when I sold them.
The KAMD300 was always preferential to the KAMD43 as despite top speed only being a fraction more it would comfortably cruise at a higher speed and not suffer from loading or a slimey bum anything like as much.

If you are getting 4000rpm then I think that is fractionally high and may simply be down to the props being tweaked a little.