June 1, 2019

blogger - Horsepower Game

Today's new boats are sold with horsepower being the important number which gives you speed and reliability.  But real World scenarios are that after a month in the water most peaked to the liter engines slow down much worse.  This is even worse as new boats are indeed heavier not because they are build stronger but because same length they have become higher and bulkier. The engines they have today are smaller, even more since the advent of pod drives.  Today an eight liter engine is 600hp ten years ago that was ten liter. 
Figures on brochures and most reviews of new boats are made on new clean hulls and running gear, checked to the millimeter, and this is not how real boating World works.  
A real boating scenario is this, a boat is usually launched in around May, owner or captain does a sea-trial, prepare it for the season, then left idle for a month or two before it starts to get used.  Running gear gets full with growth and so after a few months boat is slower to about five to ten knots with engines peaked to give maximum horse-power per cc. 
Previously to this new generation of engines boats still went well even if slower, weight distribution in most shaft boats was calculated, and in the same scenario as above you still did slow down, but the difference from the new boat figures where just a knot or two.  Today, that is about five knots.  
May be its time to starting thinking about torque in marine engines again, then putting it in the maximum horsepower per cc of recent years. 

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