Caterpillar Engine Model Guide: Matching the Right Power Plant to Your Excavator, Loader or Dozer

Every Caterpillar machine is defined by the engine under the hood. Whether you are rebuilding a 320D excavator, a 966M wheel loader, or a D8T dozer, knowing which engine model — and which serial number prefix — sits inside your machine is the first step toward buying the right engine assembly, short block, or component kit. Ordering an engine on the machine model alone is one of the most common (and most expensive) mistakes in the aftermarket. This guide maps the most frequently serviced Caterpillar machines to their factory engines, from the compact C4.4 to the mining-class C32.

1. Excavators: The C-Series Power Spectrum

Caterpillar excavators are fitted by weight class and market generation. The table below covers the machines that dominate the used and rental fleets worldwide.

Compact and small excavators

• 305.5E / 306E / 307E: C2.6 / C3.4B
• 308E / 313D2: C3.4B / C4.4 ACERT

Mid-size excavators (universal construction)

• 320D2 / 320D2 GC: C7.1 ACERT (7.0 L, 6-cylinder, the global best-seller configuration)
• 323D / 323D2 / 323D L: C7.1 ACERT
• 324D / 325D: C7 / C9
• 328D / 329D: C9

Large and heavy excavators

• 330D / 330E: C9 ACERT
• 336D / 336E / 336F: C9 / C9.3 ACERT
• 345D / 349D: C13 ACERT
• 349E / 349F: C15 ACERT
• 374F: C15 ACERT
• 390D / 390F: C18 ACERT

Mining-class excavators

• 6015B / 6020B: C27 ACERT

Note: factory fitments can vary by market tier and year of manufacture. Always confirm the engine model, arrangement number, and serial number from the engine nameplate before ordering.

2. Wheel Loaders: Power Where Traction Meets Payload

Caterpillar wheel loaders pair high-torque C-series diesels with a 1:1 torque converter match, which is why engine swaps must preserve both power and torque curve.

• 950GC / 950M / 962M: C7.1 ACERT
• 966M / 972M: C9.3 ACERT
• 980M: C13 ACERT
• 982M: C15 ACERT
• 986K / 988K: C18 ACERT
• 990K: C27 ACERT
• 992K / 993K / 994K: C32 ACERT

3. Track-Type Tractors (Dozers): High-Drive, High-Torque

Caterpillar's iconic high-sprocket dozers are engineered around low-rpm, high-torque diesels built for continuous pushing loads.

• D5K2 / D6K2: C4.4 / C6.6 (compact class)
• D6R: 3306 (early units) / D6T: C9 ACERT
• D7E: C9.3 ACERT (electric drive)
• D8T: C15 ACERT
• D9T: C18 ACERT
• D10T2: C27 ACERT
• D11T / D11T CD: C32 ACERT

4. Classic Engines Still Working Hard

Millions of older Caterpillar machines are still earning their keep, and their engines remain some of the most requested rebuild cores in the world:

• 3116 / 3126: the workhorses of 320/325-class excavators and 900-series loaders from the mid-1990s to mid-2000s
• 3306 / 3306B: legendary 10.5 L inline-6, the backbone of D6/D7-class dozers and 950/966-class loaders
• 3406 / 3406E: 14.6 L heavy-duty inline-6 used in D8-class dozers and mining trucks
• 3508 / 3512 / 3516: V-configuration mining engines for large shovels and haul units

Key Benefits

✅ Exact machine-to-engine matching for excavators, loaders, and dozers

✅ Covers C-series ACERT engines from C4.4 to C32, plus classic 3116–3406 and 3500 series

✅ Includes common engine swap and retrofit notes

✅ Nameplate-first identification guidance to prevent wrong-part orders

✅ Supported by a supplier that ships complete engine assemblies worldwide

Model / Specification Reference

About Lanxin Machinery

Guangzhou Lanxin Machinery Equipment Co., Ltd specializes in diesel engine assemblies and engine parts for construction and mining equipment. We supply complete engines, short blocks, cylinder heads, turbochargers, fuel systems, and electrical parts for Caterpillar, Komatsu, Cummins, Isuzu, Deutz, Kubota, and other major brands — each unit inspected and tested before shipment.

The engine is the most expensive single component on any machine, so get it right the first time. Send us your machine model, engine serial number, and nameplate photos, and our team will confirm the exact specification before you pay.

• Website: construction-engines.com
• WhatsApp: +86 18688416585
• Email: Sales02@lanxinmachinery.com