Used Marine Diesel Engines

Used marine diesel engines can be a cost-effective option given their relative durability. They are built to operate in demanding conditions while, at the same time, typically supplying at least 8,000 hours of power before needing a major overhaul. This is dependent, however, on having a regular maintenance schedule.

There are two types of marine engines: propulsion and auxiliary. Propulsion engines power a screw which moves an aquatic vessel across the water. Auxiliary engines supply power to all non-propulsion applications: electrical systems, water pumps, winches, environmental control systems, and more.

We offer both types of used marine diesel engines from these manufacturers:

• Caterpillar
• Cummins
• Detroit Diesel

Used marine diesel engines are available in the following conditions:

• Core
• Good Used
• High Hour Runner
• In-Framed
• Low Hour
• New Surplus
• Rebuilt

We also sell Tier 1, 2, and 3 marine engines as well as those with no tier classification.

Of course, when you buy a used marine diesel engine from us, you also receive the Depco 100% quality assurance guarantee. Our used marine engines come with a 30-day warranty, and rebuilt equipment has a 6-month warranty, excluding "as-is" inventory.

Marine Diesel Engine Applications

There are a wide range of marine diesel applications, all the way from small yachts and catamarans to supersized oil tankers and container ships. No matter the size of the vessel, marine diesel engines offer significant benefits compared to gas engines:

• Diesel burns at a lower temperature than gas which increases engine lifespan.
• Fuel auto-ignites which reduces maintenance as opposed to using a sparkplug.
• Cost per kilowatt is 30-50% lower than a gas engine.

Four-Stroke vs. Two-Stroke Propulsion Engines

The four-stroke cycle propulsion diesel engine is typically used on medium-to-large commercial vessels and generates engine speeds of 250-850 rpm. "Four stroke" means the piston moves up and down the cylinder twice while the crankshaft also revolves twice.

The two-stroke cycle diesel engine is used on deep-sea ships as it provides improved fuel economy and a greater power-to-weight ratio. The two-stroke engine only generates an engine speed of 100 rpm but, instead of refined fuel, can use less expensive heavy fuel oil. "Two stroke" means the piston moves up and down the cylinder once while the crankshaft also revolves only once.

Engine Speed

Marine diesel propulsion engines can also be categorized by speed:

• High-speed: +900 rpm (such as those used for yachts).
• Medium-speed: 300-900 rpm.
• Slow-speed: 100-300 rpm.

New vs. Used Engines

When replacing a marine diesel engine, your first preference is always to buy a new one. The relative expense, however, to do this versus a used or rebuilt engine can make this option prohibitive.

Want to learn more about the cost differential? You can always talk to us about the specific price breakdowns.

Need an engine for a tug boat, ferry, dredge, offshore workboat, supply boat, or any other vessel? Our large inventory of used Caterpillar, Cummins, and Detroit Diesel marine engines can do the job.

You can always see exactly what we have in stock by using our real-time inventory system.

Still can't locate what you need? You can count on Depco Power Systems to find it for you.