
Marine Engine
Cummins 4BTA3.9 Marine Diesel Engine (63–87 hp)
Cummins 4BTA3.9 6-cylinder diesel engine, 63–87 hp (47–65 kW), 2 ratings for marine work. Each unit nameplate-verified.
Specifications
- Engine Model
- 4BTA3.9-GM47 ~ GM65
- Cylinders & Configuration
- Inline 6, 4-cycle
- Rated Power Range
- 47–65 kW (63–87 hp) @ 1500–1800 rpm
- Aspiration
- water cooled turbocharged
- Applications
- Marine
- Documentation
- Nameplate verification + load-test record per serial number
Overview
The Cummins 4BTA3.9 is a 6-cylinder Cummins diesel engine supplied in 2 factory ratings from 63 hp (47 kW) to 87 hp (65 kW). Every rating listed on this page is a complete engine for marine duty, not a generator set, and each unit ships with its serial number recorded against the specification sheet that applies to it.
Ratings in this family differ in rated speed, peak torque and emissions tier rather than in displacement or cylinder count, so the choice between them is a duty-matching question. The specifications panel and the per-rating entries on this page are generated from the same source data, so a rating quoted here can be matched directly against a delivery document.
Specifications
The specifications panel lists the family-level values that are common to every 4BTA3.9 rating. Ratings that share displacement and cylinder count but differ in output are listed individually in the model selection section.
Model Selection: 4BTA3.9 Ratings
Each entry in this section is one rating of the Cummins 4BTA3.9. The rated power is the output at the stated speed; the peak torque figure is the value the rating develops at the lower speed shown, which is what normally decides whether a rating suits a given machine. Each rating carries a stable anchor, so a single rating can be linked or quoted directly.
4BTA3.9-GM47
4BTA3.9-GM47 — rated 47 kW (63 hp) at 1500 rpm; peak torque 52 N·m at 1500 rpm.
4BTA3.9-GM65
4BTA3.9-GM65 — rated 65 kW (87 hp) at 1800 rpm; peak torque 71 N·m at 1800 rpm.
Applications
4BTA3.9 engines in this family are normally specified for marine work.
Marine: ratings are quoted against the propulsion or auxiliary duty required, with the gearbox ratio and the duty classification taken into account.
Verification, Documentation and Ordering
Each engine is offered with nameplate verification + load-test record per serial number. That means the model and rating printed on the engine nameplate can be checked against the record issued for that serial number before shipment, which is the point most buyers of re-rated or re-exported engines want covered.
To receive a quotation, send the exact rating from the matrix above (for example 4BTA3.9-GM65), the machine or application it will drive, the quantity, and the destination port. If the rating you need is not listed, send the model and the required output and we will confirm whether it belongs to this family or to a neighbouring one.
Buyer tip: Send your 4BTA3.9 specification, quantity and destination port for a verified quotation and lead time.
Frequently Asked Questions
What is the power range of the 4BTA3.9?
The 2 ratings listed on this page run from 63 hp (47 kW) to 87 hp (65 kW), at governed speeds between 1500 and 1800 rpm.
What is the difference between 4BTA3.9-GM47 and 4BTA3.9-GM65?
4BTA3.9-GM47 is rated 47 kW (63 hp) at 1500 rpm with peak torque of 52 N·m, while 4BTA3.9-GM65 is rated 65 kW (87 hp) at 1800 rpm with 71 N·m. They use the same base engine; the higher rating is the one to specify when the driven load needs the extra torque at the lower speed.
How is a 4BTA3.9 rating ordered?
Send the exact rating shown in the model selection table, the application it will drive, the quantity and the destination port. The engine is then quoted against that rating and confirmed against its nameplate and load-test record.
At what speed is the 4BTA3.9 rated?
The ratings on this page are governed at 1500 and 1800 rpm. Rated speed fixes the speed the driven machine sees through its gearing, so confirm the governed speed before ordering rather than relying on the power figure alone.
What peak torque does the 4BTA3.9 develop?
Peak torque on this page runs from 52 N·m to 71 N·m at the lower speed shown. Where the load rises sharply, the torque available at the working speed decides the match more than the rated power does.
Is the 4BTA3.9 a complete engine or a generator set?
Every entry on this page is a complete engine. Generator sets and packaged gen-sets are listed separately from this family and are not included here.



