Professional BoatBuilder - December-January 2018

60 PROFESSIONAL BOATBUILDER

BEST

PRACTICES

E

xhaust systems are critical to any

vessel’s design. They can affect

everything from noise, vibration,

watertight integrity, and engineroom

temperature to performance, fuel

economy, and crew safety. Failing to

follow engine and generator manufac-

turer installation guidelines is, in my

experience, by far the most common

cause of system breakdown, poor ves-

sel performance, and warranty dis-

putes. Fortunately, there’s very little

new about exhaust system design and

installation, so it’s relatively easy to

avoid the most common problems.

Design Basics

 e typical inboard powerboat or

sailing vessel auxiliary is equipped with

a wet exhaust system. Nearly every wet

exhaust system includes a dry segment

between the engine’s exhaust manifold

or turbocharger and the point of water

injection, called the mixing elbow.

Because dry/wet exhaust systems are far

more common, this article will focus on

them, rather than on pure dry exhaust

systems, which are all dry, and are used

mostly in commercial applications.

In wet exhaust systems, an envelop-

ing showerhead arrangement thoroughly

For new and re t vessels, here are the fundamentals

of exhaust system design and analysis.

Text and photographs

by Steve D’Antonio

Internal

Combustion’s

Backside

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