Automotive Engineering - April 2021 - 46

Q&A
Advancing the OP engine on three fronts
Achates Power's 2-stroke, opposed-piston, compression-ignition, multi-fuel
engine marches toward multiple applications - and series production in 2024.
Larry Fromm explains.

Achates is busy on multiple fronts,
correct?
Yes. We're focused on three major projects, with OP engines ranging from 270
hp [200 kW], aimed at pickup trucks, to
over 1,000 hp [746 kW] for military vehicle applications. Currently our big
project, the Advanced Combat Engine
(ACE), is with the U.S. Army and
Cummins Engine. We've been working
on it for several years and now have
engines under test at Cummins, and
with the Army's Ground Vehicle
Systems Center (GVSC) in Warren,
Michigan, as well as here at Achates.
This engine is proof of the capability of
Achates' technology.
A 1,000-hp variant of the ACE is installed in a Bradley Fighting Vehicle and
has undergone dyno testing. Driving
tests begin in 2021 and the engine in
this power rating is planned for series
production in 2024. The Army is also
planning 750-hp [559-kW] and 1,500hp [1,120-kW] variants.
And we have a new contract to work
on a family of smaller engines for the
Army's tactical vehicles and cargo
trucks. The Army is really focused on
getting the engine into vehicles because
the Achates opposed-piston engine
doubles the power density compared
with existing diesels. We cut the volume
46 April 2021

of the engine and cooling system in half. The engine enables
faster, more fuel-efficient vehicles with longer range. It helps
their ability to engage and evade the enemy.
Would Cummins be the manufacturer?
That's up to the Army to decide. Our business model is not to
manufacture engines. It's to work with
established engine companies and license our technology to them. That's
exactly what we're doing with the ACE
project with Cummins.
Achates is doing design and development for the family of smaller-displacement engines for tactical vehicles, rated
from 300 hp to 500 hp [223 to 373 kW],
ourselves. We expect Cummins or another engine OEM will come aboard on
that one.

Larry Fromm: Achates is leveraging OP and
hybrid synergies.

We've met the
90 percent [NOx
reduction] target
using an off-theshelf aftertreatment
system.

Achates also has a program with CARB.
That's right, it's largely funded by
California's Air Resources Board. This is
the Heavy-Duty Diesel and it's the next
one most likely to go into production.
We're partnering with Aramco on this
project. It's a 10.6-L, 400-hp [298-kW]
diesel designed to replace a 13-L truck
engine. In August 2020, the state enacted legislation requiring truck engines to reduce their NOx by 90 percent. That's a huge leap, and difficult to
achieve. The Engine Manufacturers'
Association stated that it would cause
the cost of a diesel truck to increase by
$58,000.
But we've met the 90 percent target
using an off-the-shelf aftertreatment
system. We started out with a closecoupled SCR [urea injection] and kept
working on combustion-side improvements to the point where we didn't
need that type of SCR.
The second ARB project goal is lower
CO2, to meet the EPA's Greenhouse
Gas-II regulation for trucks. That one
requires steady reduction of CO2 by
2027. Well, we're already 4% below the
2027 standard.
AUTOMOTIVE ENGINEERING

ALL IMAGES: ACHATES POWER

Global demand for cleaner, more power-dense internal combustion engines (ICE) is expected to continue into the middle of this century, for a variety of vehicle applications and
markets. San Diego-based Achates Power has been developing its solution - an advanced 2-stroke, opposed-piston,
multi-fuel, compression-ignition engine - since 2004, the
year computer engineer Larry Fromm
joined the start-up to lead business
development. Automotive Engineering
recently caught up with him to learn
about Achates' progress in moving its
innovative OP power unit toward series
production in 2024. Highlights of our
interview are below.

Automotive Engineering - April 2021

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