Power & Propulsion

The Argot of the Engine Room

Know the names and locations of basic engine-room components and you won’t be embarrassed next time your mechanic comes calling.

I’ve always been fascinated by engines but I realize that a lot of powerboaters are sometimes indifferent on the subject. For them boats are what’s important, and engines are just a means to an end at best and a necessary evil at worst.

Yet no reasonable boater will deny the value of having a working knowledge of engines and engine terminology, if for no other reason than to avoid sounding like a moron when the subject arises. You have to admit, your boating pals or mechanic will be a lot more impressed by, “I believe I have an oil leak around the main bearing in my turbocharger,” than “There’s icky goo on that round green thing on top of my engine.”   

So every boater needs a basic working engine vocabulary, which he or she can use to talk intelligently about the two most expensive onboard components. But do you have one?

How about taking a little test to find out? Here are descriptions of some basic diesel-engine components. You should know the name of each one and be able to locate them on your engine. The answers are on the bottom of the following page. And no peeking.

Question 1:

What is a pump powered by exhaust gases that forces air into the engine, allowing the addition of more fuel, thus producing more horsepower? You can find it by tracing the exhaust pipe back toward the engine. It should be the first major component you come to, and it’s identifiable by two circular chambers. One contains a turbine driven by the exhaust (it’s usually discolored from heat); the other, the compressor side, contains the turbine that pumps air into the engine.

This article originally appeared in the February 2013 issue of Power & Motoryacht magazine.