What Engine is in a Cat 320C

What Engine is in a Cat 320C?

If you’re in the market for a reliable used excavator or you’re simply researching Caterpillar 320C, one of the most common questions that comes up is: What engine is in a Cat 320C?

The answer is simple but important—the Caterpillar 320C excavator is powered by the Cat 3066T engine, a proven workhorse in the construction industry.

Cat 3066T Engine Overview

The Cat 3066T is a 6-cylinder, turbocharged diesel engine known for its power, reliability, and fuel efficiency. It was designed to deliver high performance and smooth operation in demanding construction environments.

Did you know?
While it’s branded as a Caterpillar engine, the 3066T is actually manufactured by Mitsubishi Heavy Industries in Japan. Caterpillar and Mitsubishi had a long-standing partnership in engine development and manufacturing, especially for machines built in Caterpillar’s Japanese facilities.

This collaboration results in an engine that combines Japanese engineering precision with Caterpillar’s durability and global parts support.

Build Year of the Cat 3066T:
The Cat 3066T engine was first introduced in the mid-1990s and has been a staple in Caterpillar’s lineup for excavators like the 320C ever since. Its long production run speaks to its reliability and the trust that contractors and heavy equipment operators place in it.

Key Specs of the Cat 3066T Engine:

• Engine Model: Cat 3066T

• Type: Turbocharged, water-cooled, 4-stroke diesel

• Displacement: 6.6 liters (403 cubic inches)

• Gross Power: Approximately 138 horsepower (103 kW)

• Emissions: Meets EPA Tier 2 standards

• Place of Build: Made in Japan by Mitsubishi

• Build Year: First introduced in the mid-1990s

• Engine Serial Number Prefixes: Common prefixes include 6HK, 7JK, 1YK, 4YZ, and 9YZ

Engine Serial Number (ESN) – What You Need to Know

The engine serial number (ESN) is a unique identifier for the 3066T engine. It’s typically stamped on a metal plate located on the right-hand side of the engine block, near the oil filter or injection pump.

A full engine serial number might look like this: *7JK12345*
This number is important for:

• Ordering parts

• Verifying engine origin

• Checking service history

• Confirming engine authenticity in used equipment

Why the Cat 3066T Matters

When buying used equipment, the engine is one of the first components to check. The Cat 3066T (by Mitsubishi) stands out because it is:

• Highly Durable: Built for heavy-duty jobs and long service life

• Fuel Efficient: Delivers performance while keeping fuel costs under control

• Globally Supported: Caterpillar’s worldwide dealer network makes parts and service easy to access

• Trusted by Contractors: A favorite for reliability and value retention

A Reliable Choice for Contractors

The Caterpillar 320C, equipped with the Japan-built 3066T engine, remains one of the most reliable and cost-effective excavators in the 20-ton class. Whether you’re working on roads, pipelines, demolition, or earthmoving, this machine is built to perform.

Looking for a Used Cat 320C for Sale?

We offer high-quality used Caterpillar 320C excavators, made in Japan and powered by the original Mitsubishi-built 3066T engine. Each unit is inspected, serviced, and ready for export at a very competitive price.