"Do you know the three secrets of a fast boat?"asked me many years ago by an American colleague in the racing hotspot Sarasota in Florida.
Of course! And I replied"Torque, torque, torque and reduce friction"which he acknowledged with a broad grin.Torque stands for torque andreduce friction for a reduction in resistance. This is exactly what it's all about if you want to make a boat faster.
We've all been there: the first thing you do is replace the aluminium propeller on the outboard motor with a stainless steel one with a higher pitch and mount the motor a little higher. Although this helps a little, it doesn't help much, because a propeller that is too steep stalls the engine.
However, if it hangs too high, the propeller will quickly draw air. In this case, height means how high or how low the anti-cavitation plate of the motor is mounted above or below the bottom of the boat. The mounting height is specified by the manufacturer, but can be varied.
If the motor hangs too low, too much of the underwater part is in the water, which increases the resistance and therefore has a negative effect on the speed. This also leads to more splashing at the stern, creating veritable fountains.
If the engine is mounted too high, this can lead to cooling problems and the propeller drawing in air and ventilating even at the slightest steering angle. Another consequence: the boat has difficulty gliding because the propeller does not grip sufficiently.
An adjustable bracket on the mirror, on which the motor is then mounted, is more useful. With this bracket, which is available for almost every performance class, the motor can be precisely adjusted in height. In principle, a distinction is made between two types: ...
You can read the full article in the December issue from BOOTE, which will be available at newsagents from 14.11.18 - Subscribers sooner, of course. Or you can download the PDF below.
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