Generac
Generac G12.9L G20
Legacy Liquid-Cooled Gas
Generac G12.9L G20 is a legacy 12.9 L inline-six spark-ignited industrial generator engine used across historical SG and MG 150-300 kW gaseous generator sets. EPA families CGNXB12.92C1, CGNXB12.92C2, CGNXB12.92N1 and DGNXB12.92C4 record matching stationary 1800 RPM configurations at approximately 226-230 kWm.
Overhaul & repair parts- Manufacturer files
- No datasheet
- Last updated
- 2026-07-25
- Package route
- gas generator sets
- Mechanical Output
- 230 kW
- Cylinders
- L6
- Displacement
- 12.9 L
- Rated Speed
- 1,500 RPM
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Generac G12.9L G20 overhaul & repair parts
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Generac G12.9L G20 generator set context
The Generac G12.9L G20 is listed here as a natural gas generator-drive engine for 50 Hz generator sets, with a headline 230 kW / standby rating. Use this page to compare the published engine output, electrical kWe/kVA ratings, emissions level, datasheet availability, and neighboring models before specifying an alternator, controller, enclosure, voltage, and compliance package.
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Technical Specifications
| Brand | Generac |
| Model | G12.9L G20 |
| Series | Legacy Liquid-Cooled Gas |
| Configuration | L6 Turbocharged Aftercooled |
| Cylinders | 6 |
| Displacement | 12.9 L |
| Fuel Type | Natural Gas |
| Ignition Type | Spark Ignition |
| Cooling Method | Liquid-Cooled |
| Emissions Standard | U.S. EPA Stationary |
| Certifications | U.S. EPA Stationary, U.S. EPA NSPS Subpart JJJJ |
| Country of Origin | United States |
| Year Introduced | 2012 |
| Year Discontinued | 2022 |
Frequently asked questions
What fuel does the Generac G12.9L G20 use?
The Generac G12.9L G20 is a Natural Gas generator-set engine.
What is the displacement and cylinder configuration of the G12.9L G20?
The Generac G12.9L G20 is an inline-6 (6-cylinder) engine with a displacement of 12.9 L.
What emissions information is listed for the G12.9L G20?
This record lists U.S. EPA Stationary for the Generac G12.9L G20. Confirm the exact engine family, model year, configuration and applicable manufacturer certification documents before specifying it for a regulated project. A database label does not establish certification of a complete generator package.
Is the G12.9L G20 still in production?
No — the Generac G12.9L G20 is discontinued (production ended around 2022). Its specifications and datasheets remain archived here for reference.