Achates Power and Cummins develop leap-ahead capability for the US Army Ground Combat Fleet

A joint development team from Achates Power and Cummins Corporate Research and Technology has been running at full throttle for over a year to develop an opposed-piston Advanced Combat Engine (ACE) for the U.S. Army.  The engine is part the US Army’s 30-year strategy to modernize tactical and combat vehicles.

After several years of technology demonstrations and an intense competition, the Army kicked off the path to production by selecting the Achates Power / Cummins team last summer.  This $47.4 million contract through the National Advanced Mobility Consortium propels the 1000 HP 4-cylinder ACE variant to Technology Readiness Level 6, which will make it suitable for in-vehicle and real-world testing.

In March, our single-cylinder test asset passed an aggressive 80-hour durability test; and, the Army displayed a scale model of the engine at the Association of the United States Army’s Global Force Symposium and Exposition in Huntsville, Alabama.

Several big milestones are coming up:

  • October 2018: A full-scale show model of the engine will be on display at the 2018 AUSA Annual Meeting and Exposition.
  • November 2018: The joint Achates Power and Cummins development team will present initial engine testing results to the Army.
  • Mid-2019: The ACE engine will present a technology demonstrator – TRL 6 (Technology Readiness Level).
  • Mid-2020: Demonstration in a US Army combat vehicle.

There is a lot of work to be done.  The funding that the Army has planned will deliver Low Rate Initial Production of the first ACE variant in 2022. To fully realize the benefits of this architecture we’ve started plans for additional variants, and we are working with the platform teams and military OEMs to make sure that spiral insertion is primed as the variants come on line.  All of this while focusing on and flawlessly executing the ACE program.

A powerpack featuring the ACE engine will deliver double the power density of any existing Military-off-the-shelf powerpack at half the cost.  This kind of capability does not currently exist, and will enable vehicle optimization for survivability, package, range, and lethality that has previously never been possible.  Until the selection of the Achates Power / Cummins team, the Army has not had a plan to feasibly execute such a game-changing engine.  Now that we know how to do it, we owe it to our warfighters to deliver such capability, and I couldn’t be prouder to be a small part of the team that is doing it.  I look forward to sharing future updates!

15 thoughts on “Achates Power and Cummins develop leap-ahead capability for the US Army Ground Combat Fleet

  1. “A powerpack featuring the ACE engine will deliver double the power density of any existing Military-off-the-shelf powerpack at half the cost. ”

    This is a stronger selling point than improved efficiency and emmisions in the target light truck market.

    • Emissions and efficiency is a very strong selling point in the passenger and commercial vehicle market, in addition to power density. Customers buy HP and Torque, but manufacturers need to meet the regulations that are in place. As we’ve discussed before the 2.7L OP Engine, like every engine project we work on with customers, is designed to meet specific targets for emissions, efficiency and power.

      • If emissions and efficiency were stronger selling points than power density and cost, Atchison cycle engines would now dominate the light truck market. Currently Atchison cycle engines are only used in efficiency optimized cars (e.g. PHEVs, like the Niro I just purchased).

        Your CEO recently made the point that auto makers are obsessed with EVs because of government regulations but almost no one buys them (~1% MS). OPGCI engines will suffer the same fate unless you give the end customer power density and cost first and efficiency and emissions second.

        The good news is that the OPGCI can do it all. It’s only slightly more efficient than an Atchison cycle engine but it wins big on power density and cost.

  2. Atchison cycle engines almost match the efficiency of OPGCI engines (40 vs 45%), but they are not used in light trucks. Why not? Because power density and cost are more highly valued by CUSTOMERS than efficiency and emissions.

    Your CEO recently noted that electrified car development is being driven by.government regulations but nobody is buying them (<1% MS).

    Emphasizing efficiency and emissions will please regulators but you will sell more engines if you emphasize 2x power density and cost first with great efficiency and emissions as "frosting on the cake".

  3. @ Charles Hart, I fully agree efficiency is key. But for better or worse, with a few exceptions, no one gets to sell any engines without satisfying the government.

  4. I have experience with the FM 38 5-1/4 engines which were designed for marine propulsion and power generation. Was pleasantly surprised at the undertaking of OP for ACE in the early 2000s. Was hoping for a development for civilian apps. This development of opgci has opened my eyes of extending the internal combustion engine for another 50yrs plus. What I want is to see them asap in apps that have the most production numbers to allow for lower costs. Although not a Ford fan would buy one at the first introduction.

  5. I agree with Bryon Kass. I live in Southeast Alaska, which has an aging Commercial Fishing fleet. I know several vessel owners that are extending the replacement of their current engine in anticipation that the Achates will be in production soon. This engine design will change the market for the better. Marine propulsion market in Alaska will greatly benefit.

  6. I am a retired engineer (University of Portland graduate class of 1956). While in Okinawa (1957) I had the one and only one occasion to observe an opposed piston diesel engine operate, on board a medium landing craft. The engine was an Alis Chalmers six cylinder with a roots type blower. When at the university I had the opportunity to talk with Russel Bourke who was at the end of his career (developing what he called a “Free Piston” engine. It was a small 2 stroke engine with a scotch yoke attachment to
    the crankshaft. It operated at high speed and high compression. He did manage to get cooperation with the the company
    operating Portland’s public busses in a trial using his engine running a generator and electric motors driving the bus. Those two
    experiences gave mean interest in internal combustion engines that has been with me all my life. If I had discovered a company
    such as yours, I would have surely dedicated my engineering career to it!!

    Russel Bourke was basically a talented machinist. He did not understand the thermodynamics he had created. At the time he was
    corresponding with a German engineer whom he said was developing a theory of the thermodynamics which was taking place
    within the engine. Russel did get his engine on a dynamometer , it produced about 120 hp from 20 cubic inches, at very high RPM.

    Currently Evinrude appears to be having problems with their injectors resulting in piston and other damage to their Etec outboard motors. This is probably the same difficulty discussed in one of your articles on direct injection applied to two stroke
    engines. This is most likely the same problem that the Pre BPR Evinrude had with the Fitch injection, which led to their bankruptcy.

    Mercury has recently stopped production of their “Optimax” two stroke engines, except for one three cylinder model used for shallow water jet boat installations. This at first surprised me, as their Optimax engines, with their “Orbital Engine”designed
    injection systems had been well accepted and relatively trouble free. After taking a look at their new four cylinder four stroke
    engines, I think I understand what was involved with their decision. I’m not sure that the same thinking applies to their new
    V/8 series of outboards.

    Also Yamaha’s abandonment of two stroke has puzzled me. Did they forsee the problems that Evinrude have. A friend of mine
    who operates a freight and ware house business had Yamaha as a customer at the time they were manufacturing two strokes.
    Yamaha ordered him to destroy all two strokes in his warehouse. That was a shock to me.

    I appreciate being able to contact your company and please keep me informed of your progress. Thanks

    • Patrick,
      Thanks for the comments and background, it’s always nice to hear stories from people who have come across OP Engines in the past and share the passion for engines. Please sign up for our newsletter, or follow us on Facebook, if you’re interested in hearing of our progress. It’s a busy time for us and we hope to have lots of good news in the future.

  7. Your 2.7L in the F-150 seems like a dream come true. I have an 11 year old Dodge with the 5.7L V8 that I would like to replace, but am reluctant to do so until your engine becomes available. Can you give an estimate of when your engine will be for sale in pickups? Since Dodge (RAM) uses Cummins diesels and Cummins is working with Achates, will RAM get the 2.7 or something similar?

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