Quote:
Originally Posted by HOBO-S34
I have a Sabre 34 with a Westerbeke 30B engine. My cruising speed at 2700 RPM is max 5 knots. I can get a little more speed if I up the rev's to 3000 plus (only did that as a test). I think I am under proped. Any suggestion for a three bladed prop size. Boat is relatively new to me and I do not know the prop size.
Mike
|
Hello Mike,
The
Hull Speed on the boat is 7.12 knots with clean
hull and excellent conditions under
sail
The engine produces max torque at 2,021 RPM - and 19 HP.
For best consumption/speed/sound - around 1,800 RPM.
Max rated RPM on that engine is 3500 = 27 Hp
Your cruising speed is 5 knots at 2,700 RPM (+/- 22HP)
Before,
buying a new prop with different diameter or
pitch.
Dive and check the prop and
hull for fouling. It they are clean, measure the diameter - can't measure
pitch easily under
water.
The Sabre 34 may have a user group who can advise on the size/pitch they have found best suits the engine and the
gearbox's reduction ratio.