A 77-litre diesel engine in the 3 MW class has run for the first time in Gunsan, South Korea. HD Construction Equipment said on 15 October that it had held a start-up ceremony for the DX77 at its Gunsan campus. It is the largest engine the company has developed, and it is aimed at power for AI data centers. Full performance and durability testing comes next; series production is planned for 2028.
A High-Speed Block at 1,800 rpm
The DX77 runs at 1,800 rpm, and the company claims the best fuel efficiency and output in its category. According to the Seoul Economic Daily and ZDNet Korea, it also points to high-strength, wear-resistant materials and a high-efficiency cooling system for long running at speed, and to filter change intervals stretched to 1,000 hours. A long service warranty is to come with the launch, which the company calls the longest in the industry. The cylinder count, the emission certification and the split between standby, prime and continuous ratings have not been published.
The company says the engine gives a lot of power for its size and so takes less floor space, and it presents the DX77 as a fit for modular data centers that add generating capacity in steps as their load grows. The design leaves room for later versions running on gas or hydrogen.
Four Ratings, One New Plant
The DX77 sits at the top of a line-up the company wants complete by 2029. The 1 MW DX22 is built today at the Incheon plant. A new engine plant in Gunsan, due to be finished at the end of October, is to start the 1.5 MW DX37 in early 2027 and has a stated maximum output of 1,250 engines a year, ZDNet Korea reports. The DX77 follows in 2028 and the 2 MW DX50 in 2029, which gives a range from 1 to 3 MW.
North America is the market the company names. It says AI data center growth and delays in connecting to the grid are raising demand for on-site generation there, and it plans to widen its gas engine range for that market. ZDNet Korea recalls that on 7 October the company signed a 390 billion won contract to supply engines for a U.S. data center. Company president Moon Jae-young was quoted by the Seoul Economic Daily as saying that the DX77 would take the generator engine business to a new level and that thorough testing would shape the final product.
Two Years Between Ceremony and Data Plate
For anyone who builds sets around engines, the date matters as much as the rating. 1,800 rpm is the 60 Hz speed, which fits the North American target; nothing has been said about a 1,500 rpm version for 50 Hz markets. Until type tests and emission certificates are out, a DX77 cannot be written into a specification, and the first packaged sets will follow the 2028 production start, not this week's ceremony.
Two details in the announcement say more about the intended duty than the headline output. A 1,000-hour filter interval and a long warranty count on an engine that runs every day as prime or bridging power while a grid connection is awaited; a standby set that runs its monthly test hardly notices either. The footprint argument points the same way. A campus that grows hall by hall adds generation in blocks, and fewer, larger sets per megawatt mean fewer genset containers, exhaust runs and fuel connections to lay out. The large high-speed engine field is filling up - Perkins started series production of its 61-litre 5016 earlier this month, rated at 50 Hz - and buyers will weigh service cover on site as heavily as the figure on the data plate.
Sources: Seoul Economic Daily, ZDNet Korea