ENGINE AND PROPELLER

The boat has a 260 HP Yanmar turbo diesel engine. Max speed at full throttle is 18 mph. This has to be some kind of a record for sailboats. We cruise at 14 mpt at less than 1/2 throttle.

This photo shows the engine rooom.  This is the compartment aft of the watertight bulkhead.  As you can see, every part of the engine is completely exposed. Access to the engine and all other mechanical equipment is far better than in any comparable yacht.

 

 

   

   

ENGINE INSTALLATION:  The engine is big for a boat of this size, but we wanted the ability to punch thru heavy seas at high speed.  The strut, shaft, bearings, mounts and all drive train components are oversized and designed for extra long life.  The engine is mounted under the cockpit.  The 20 inch diameter Max prop is full feathing for greatly reduced drag when sailing. 

The engine's position has monumental advantages:

1.  Safety. All engine thru hulls, exhaust tubing, muffler, shaft log, strut and engine water hoses and rudder are behind a solid, watertight bulkhead.  If a thru hull or hose fails, or if the prop, shaft, strut or rudder strikes an underwater object hard enough to cause damage,  the rear compartment will fill to about 12" deep, but  the bulkhead will protect the boat from flooding.  This is a major safety advantage, since these are the items that are the most vulnerable to damage that could cause loss of the boat.

2.  Soundproofing. This is the quietest and most vibration free engine installation you will find on any production sailboat.  Noise levels in the main cabin are unbelievably low.  Here are some decibel readings.  For the boats, readings were taken at 8 knots.  A few cars were thrown in for comparison.  For the cars, readings were taken on smooth freeways, windows closed, at 60 mph.  A 10 point change in decibel readings means a doubling of the noise level.

 

         MacGregor 65                    63

         Swan 68                             69

         Beneteau 35s5                   78

        Freedom     38                    85

         Cadillac Sedan de Ville    72

         Ford Taurus                      76

          Corvette                           76

 

Excessive engine noise on long passages can wear you down.  The injector clatter on most modern diesels can be murder.  Most sailboat engines are in the main cabin, and are so loud that conversation is difficult.  A few hours of that and you will be ready to shut it off.  Under power with the rear engine,  it is like sailing.  The muffler and prop, often sources of objectionable
noise, are also isolated from the main cabin.  This boat is quiet.

3. Rudder control.  The rear engine position places the propel­ler right near the rudder, so the prop blast has lots of effect on steering ability, both in forward and reverse.  If the helm is put over hard, the transom will swing in the direction that you in­tend before the boat starts to move forward or to the rear.  This is really useful in docking.  Few sailboats have better steering control, at any speed, whether going forward or backwards.

4. Engine heat and odor.  Engines get hot, and give off un­pleasant fuel smells.  Even the most meticulously cared for yacht usually smells of diesel.  Placing the engine behind a watertight bulkhead really fixes this big problem.  An engine mounted in the main cabin can heat up the living areas.  This may be fine in the winter, but is a disaster in the summer.

5.  Thrust.  The downward thrust of the prop at the stern of the boat helps lift the stern and prevent it from squatting, giving a bit more speed.  If the prop is near the keel, it tries to lift the entire boat.  Not so good.