80 — By Capt. Bill Pike — November 2002
Fast & Fine
|Gerry’s Magical Portable Dyno|
Lazzara Yachts has used the services of JEI (Janelle Engineering, Inc.) during sea trials of the last five 80s, as well as for the sea trials of other vessels it currently builds. JEI's PowerMate system records and graphs torque, thrust, horsepower, rpm, trim and heel angles, speed, voltage, amperage, engine temperatures, and GPS positioning without restricting engine horsepower. During a sea trial a JEI engineer secures wireless strain gauges to the prop shaft(s), the gauges communicate with a laptop nearby, and that laptop communicates with another laptop on the bridge, where the engineer conducts actual testing.
According to Lazzara, accurate shaft horsepower measurements taken from JEI's portable dyno--as opposed to theoretical fuel, horsepower, and other numbers supplied by engine manufacturers--are invaluable for specifying props and diagnosing performance problems like the one we encountered during our PMY sea trial. --B.P.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.