HYDROGEN TEST ALERT
COOPER ANNOUNCES MAJOR METHANE BREAKTHROUGH
Cooper has successfully tested a slow-speed integral engine running on a hydrogen (H2)-natural gas fuel blend. The groundbreaking test comes 5 months after the announcement of Cooper’s joint hydrogen research project with a major U.S. gas pipeline company to demonstrate the safe operating range of H2 blends in large-bore internal combustion engines.
“Cooper’s hydrogen development initiative took another large step forward today. We ran an unmodified large-bore, slow-speed integral engines-compressors with an H2 blend of 5% by volume, and we achieved significant reductions of methane in the exhaust. This is the first such run using significant amounts of hydrogen in an engine of this design.” said Cooper COO, Malcolm Holmes. “In May, we will be running up to 33% by volume in the same stock engine. Our customers have thousands of similar units running globally, so the potential reduction of methane is substantial.”
The Cooper test was conducted at their slow-speed integral engine test cell at corporate headquarters located in Houston, Texas. The test engine is the current production, NSPS compliant CleanBurn PlusTM AJAX® 2802 with 15″ piston bore, 16″ power stroke, and a speed range of 360-440 RPM. Cooper selected the AJAX engine due to the similarities of its combustion system to that of the large fleet of the other engine brands the company services (Clark, Cooper-Bessemer®, Ingersoll Rand, and Worthington).

in the control room during the hydrogen test.
IN DEPTH EXPERTISE, CAPABILITIES, AND PARTS INVENTORY
AJAX Overview
Since 1959, Cooper has been the O.E.M. of AJAX integral engines-compressors and after-sale support. During our ownership, the AJAX product line has earned a reputation for reliability, efficiency, and durability of service. Our AJAX product line, ranging from 147 to 845 hp (110 to 630 kW), reduces overall operating costs and maintenance expenses and delivers worry-free service.
Cooper’s after-sale support structure delivers full service for AJAX integral engines-compressors from parts, to repairs, to engineering, to field support for any make or model, all from one source.

ajax Engine-Compressor parts
Genuine O.E.M. Cooper parts for AJAX integral engines and compressors are backed with decades of engineering, manufacturing, and in-field experience in material wear. We provide spare AJAX engine parts that are manufactured to the latest standards and technical advancements. From our AJAX parts manufacturing center in Houston, Texas, we are committed to making every AJAX part with our own brand of O.E.M. quality and to O.E.M. standards. We are committed to stocking and delivering AJAX engine parts to our customers quickly and efficiently, and that’s why we house thousands of AJAX part numbers at our dedicated central distribution center in Houston, and in field locations around the world.
AJAX SERVICE & REPAIRS
For decades, Cooper has provided a complete line of field and shop services for AJAX integral engines and compressors. From preventative maintenance, to shop and field overhauls, to field machining, to repairs throughout our global shops, our Cooper service teams are fully trained on AJAX engines and compressors, and stand ready to assist our customers with all their service needs.


AJAX Engine-Compressor UPGRADES
Cooper has spent decades providing technology and engineering services for AJAX engine and compressor upgrades. With our advanced technologies, expertise, and project management experience, we offer AJAX upgrades to reduce engine emissions, increase horsepower, improve efficiencies and reliability of your equipment, and reduce maintenance costs.
To further strengthen our upgrade portfolio for AJAX engines, Cooper acquired HOERBIGER’s Engines Services (HES) division in 2019. Cooper now offers even more upgrade technologies including the HyperLogic™ and ePCC™. The Engine Services team has been offering engine emissions reduction and efficiency improvement upgrades, applicable to all types of AJAX integral engines.
NEW AJAX ENGINES & COMPRESSORS
Legendary AJAX integral engines and compressors have been serving the industry’s compression needs for decades. Ranging from 148 to 845 hp (110 to 640 kW), the reliable two-stroke design of AJAX equipment results in one of the most maintenance-free engines-compressors on the market. Today, AJAX integral engines-compressors continue to earn their distinguished reputation for being as close to worry-free as any compressor product in the world. The AJAX product line maintains a compressor cylinder offering capable of handling a wide range of pressures, from vacuum to 5,500 psi (379 bar). AJAX compression cylinders offer up to six ratios of capability and the lowest brake hp per million flows for a wider range of applications, including sour gas.

EXCEPTIONAL QUALITY & ABSOLUTE DEPENDABILITY
Since 1877, the AJAX brand has been synonymous with exceptional quality, absolute dependability, and unbeatable performance. To this day, AJAX offers the highest compression per brake horsepower in the industry.
AJAX balances performance and product design while meeting the industry’s stringent compliance requirements. AJAX customers can be confident knowing they have Cooper’s support from initial planning and purchase to installation and field service for legacy and new equipment.
Cooper is proud to service AJAX legacy engines, integrals, and compressors, as well as provide standard replacement and overhaul parts. A vast inventory stands ready to ship new and reconditioned parts, exchanged parts, and conversion kits where you need them most.

AJAX Engine & Compressor Upgrades
Code | Title | Description | Outcomes |
---|---|---|---|
AJI20001 | 440 RPM Upgrade | This upgrade increases the speed of large-bore AJAX units from 360 and 400 rpm to 440 rpm, increasing horsepower ratings while maintaining emissions ratings. | Power Increase |
AJI20002 | Auto Pre-Lube Systems | Pre-Lube systems are standard equipment on current production AJAX units, offered with manual, electric or pneumatic configurations. Now retrofit kits are available for all AJAX units. | Safety, Reliability, Maintenance |
AJI20003 | Compressor Poppet Valves | Poppet valves deliver the highest efficiency of any valve design. Compared to conventional plate, channel or strip valves, poppet valves offer significant fuel or horsepower savings through more efficient and reliable operation. | Efficiency, Reliability, Maintenance |
AJI20004 | Dry Type Air Filter Conversion | New AJAX integral engine-compressors are packaged with “Dry Type” engine air filters. Now AJAX owners with the older oil bath type air cleaner can benefit from this product improvement. | Efficiency, Power Increase, Reliability, Maintenance |
AJI20005 | Exhaust Expansion Chambers | The AJAX exhaust expansion chamber uses exhaust pulsations to optimize the scavenging of the power cylinders while providing substantial increases in the mass of fresh air that is trapped inside the cylinders, recovering horse power losses often associated with high elevation and/or emission compliance. | Efficiency, Emissions, Power Increase, Maintenance |
AJI20006 | Flexible Fuel Header System | The flexible fuel header system eliminates header misalignment by utilizing single piece fuel header system and eliminates stress and distortion on gas valve body. | Maintenance |
AJI20007 | "Economizer" Gas Injection System | The advantage of an AJAX engine equipped with the available “Economizer” gas injection system versus the standard low pressure fuel system is to reduce fuel consumption by up to 33%. | Efficiency, Reliability |
AJI20008 | HCR (High Compression Ratio) Power Pistons | The HCR pistons provide enhanced air flow at higher elevations where air density is lower. More air flow equates to better engine performance, lower emissions and improved fuel consumption at higher elevation applications. | Efficiency, Emissions, Power Increase |
AJI20009 | Integrated Governor Throttle Body (IGTB) | This product can be used for units that use automatic variable speed operation for load control and is now standard equipment on all new 2801, 2802, 2803 and 2804 units. | Efficiency, Reliability, Maintenance, Safety |
AJI20010 | Integral Concrete Skid | AJAX engine-compressors can be purchased with a skid design that allows for the unit to be portable. | Installation Costs, Portability |
AJI20011 | Low Emissions "LE" Conversion Kit | The main component of the system is the ignitor assembly that creates a high energy ignition source, igniting a leaner mixture of fuel, resulting in lower NOx formation and cleaner exhaust. | Emissions, Reliability |
AJI20012 | Noise Control | Cooper offers a variety of methods for meeting your sound level requirements. | Noise Control |
AJI20013 | Oxidizing Catalytic Converter | The AJAX oxidizing catalytic converter is designed to meet the new environmental guidelines for 2-stroke, lean-burn (2SLB) gas engines, with impressive removal efficiencies of CO, VOC, and H2CO. | Efficiency, Emissions |
AJI20014 | Integral Engine-Compressor Reconfiguration | Cooper offers complete reconfigured compressor package solutions for your legacy equipment. | Repurposing |
AJI20015 | Rebecca Fuel Cartridge | With Rebecca system, fuel gas injector valve removal, inspection and replacement are fast and easy. The two-part system consists of a permanent valve body and replaceable cartridge assembly. | Efficiency, Maintenance |
AJI20016 | Ring Gear Starting | Many end-users are faced with declining site gas pressures. Air-in-head start systems require 200-250 psig pressure. Ring gear start systems only require pressures as low as 30 psig. | Maintenance, Safety |
AJI20017 | Scavenging Intake Poppet Valve | The Scavenging Intake Poppet Valve is the latest step in airflow improvement. The poppet valve design increases the flow area over the reed strip design, allowing more scavenging air to the combustion chamber that subsequently increases combustion efficiency. | Efficiency, Emissions, Power Increase, Maintenance |
AJI20018 | Screw In Pre-chamber | The AJAX screw-in pre-chamber (SIP) can be the first step in your emissions-reduction program by reducing NOx emissions. Adaptable to other emissions-reduction technologies, the SIP provides proven reliability, reducing NOx emissions and fuel consumption. | Efficiency, Maintenance, Safety |
CPE20001 | Electronic Pre-Combustion Chamber (ePCC) | Electronically controlled pre-combustion chamber check valve (ePCC™) precisely controls fuel injection and allows the engine to run consistently smoother and cleaner | Combustion stability, Reliability, Maintenance |
CPE20002 | HyperLogicTM | Advanced air/fuel ratio control system for two- and four-stroke, turbocharged, spark-ignited engines | Efficiency, Emission, Reliability, Maintenance |
Engine Controls | Control Panel Upgrades | Control panel upgrades tailored to customer’s specific needs and requirements for most makes and model of gas compression and power generation engines. | Combustion stability, Efficiency, Emission, Reliability, Maintenance |
Lubrication System | Sloan Lubrication System | Protect your investment with a leading lubrication system. Optimized design, maximized compressor valve life, reduced lube oil carryover, preventative equipment damage and downtime, and fail-safe protection for your critical machinery. | Efficiency, Emission, Reliability, Maintenance |
AJAX Integral Engine-Compressor Legacy and Current Product Models
Designed for simplicity and durability since the 1950s, many AJAX integral engine-compressor units are still in service today. A low-maintenance, reliable piece of equipment is comprised only of components that are strictly necessary. Fewer parts means a smaller margin for error.
Model | Bore × Stroke (in) | Rated Speed (rpm) | Rated HP (bhp) | BMEP (psi) | Number of Power Cylinders |
---|---|---|---|---|---|
DPC-60 | 9½ × 12 | 475 | 58 | 56.5 | 1 |
DPC-120 | 9½ × 12 | 475 | 115 | 56.5 | 2 |
DPC-80 | 11 × 14 | 400 | 77 | 57.1 | 1 |
DPC-160 | 11 × 14 | 400 | 154 | 57.1 | 2 |
DPC-81 | 10½ × 12 | 475 | 78 | 62.4 | 1 |
DPC-162 | 10½ × 12 | 475 | 156 | 62.4 | 2 |
DPC-105 | 12 × 14 | 425 | 101 | 59.3 | 1 |
DPC-115 | 13¼ × 16 | 360 | 110 | 55 | 1 |
DPC-115LE | 13¼ × 16 | 360 | 110 | 55 | 1 |
DPC-230 | 13¼ × 16 | 360 | 221 | 55 | 2 |
DPC-230LE | 13¼ × 16 | 360 | 221 | 55 | 2 |
DPC-140 | 13¼ × 16 | 400 | 134 | 60.3 | 1 |
DPC-140LE | 13¼ × 16 | 400 | 134 | 60.3 | 1 |
DPC-280 | 13¼ × 16 | 400 | 269 | 60.3 | 2 |
DPC-280LE | 13¼ × 16 | 400 | 269 | 60.3 | 2 |
DPC-450LE | 13¼ × 16 | 400 | 432 | 64.6 | 3 |
DPC-300 | 15 × 16 | 360 | 288 | 56 | 2 |
DPC-300LE | 15 × 16 | 360 | 288 | 56 | 2 |
DPC-180 | 15 × 16 | 400 | 173 | 60.5 | 1 |
DPC-180LE | 15 × 16 | 400 | 173 | 60.5 | 1 |
DPC-360 | 15 × 16 | 400 | 356 | 60.5 | 2 |
DPC-360LE | 15 × 16 | 400 | 356 | 60.5 | 2 |
DPC-540 | 15 × 16 | 400 | 540 | 63 | 3 |
DPC-540LE | 15 × 16 | 400 | 540 | 63 | 3 |
DPC-720 | 15 × 16 | 400 | 720 | 63 | 4 |
DPC-720LE | 15 × 16 | 400 | 720 | 63 | 4 |
DPC-600 | 15 × 16 | 400 | 576 | 67.2 | 3 |
DPC-600LE | 15 × 16 | 400 | 576 | 67.2 | 3 |
DPC-800 | 15 × 16 | 400 | 768 | 67.2 | 4 |
DPC-800LE | 15 × 16 | 400 | 768 | 67.2 | 4 |
DPC-2201 | 13¼ × 16 | 440 | 148 | 60.4 | 1 |
DPC-2201LE | 13¼ × 16 | 440 | 148 | 60.4 | 1 |
DPC-2202 | 13¼ × 16 | 440 | 296 | 60.4 | 2 |
DPC-2202LE | 13¼ × 16 | 440 | 296 | 60.4 | 2 |
DPC-2801 | 15 × 16 | 440 | 192 | 61.1 | 1 |
DPC-2801LE | 15 × 16 | 440 | 192 | 61.1 | 1 |
DPC-2802 | 15 × 16 | 440 | 422 | 67.2 | 2 |
DPC-2802LE | 15 × 16 | 440 | 384 | 61.1 | 2 |
DPC-2803 | 15 × 16 | 440 | 634 | 67.3 | 3 |
DPC-2803LE | 15 × 16 | 440 | 600 | 63.7 | 3 |
DPC-2804 | 15 × 16 | 440 | 845 | 67.2 | 4 |
DPC-2804LE | 15 × 16 | 440 | 800 | 63.7 | 4 |
AJAX Gas Engine Product Models
The AJAX gas engine offers less maintenance, lower field costs, and a proven, rugged design. The standard single-cylinder, two-stroke, clean-burning engine meets current federal emission regulations without additional control systems.
Model | Bore × Stroke (in) | Rated Speed (rpm) | Rated HP (bhp) | BMEP (psi) | Number of Power Cylinders |
---|---|---|---|---|---|
EA-15 | 5 × 6½ | 900 | 14 | 49.6 | 1 |
EA-22 | 6½ × 8 | 650 | 21 | 48.5 | 1 |
EA-30 | 7¼ × 8 | 650 | 29 | 53.1 | 1 |
C-30 | 7½ × 10 | 525 | 29 | 49.2 | 1 |
C-42 | 8½ × 10 | 525 | 40 | 53.6 | 1 |
E-42 | 8½ × 10 | 525 | 40 | 53.6 | 1 |
E-565 | 8½ × 10 | 525 | 40 | 53.2 | 1 |
DP-60 | 9½ × 12 | 475 | 58 | 56.5 | 1 |
DP-80 | 11 × 14 | 400 | 77 | 57.1 | 1 |
DP-160 | 11 × 14 | 400 | 154 | 57.1 | 2 |
DP-81 | 10½ × 12 | 475 | 78 | 62.4 | 1 |
DP-115 | 13¼ × 16 | 360 | 110 | 55 | 1 |
DP-230 | 13¼ × 16 | 360 | 221 | 55 | 2 |
DP-125 | 13¼ × 16 | 380 | 120 | 56.7 | 1 |
DP-250 | 13¼ × 16 | 380 | 240 | 56.7 | 2 |
DP-165 | 15 × 16 | 380 | 158 | 58.4 | 1 |
DP-325 | 15 × 16 | 380 | 312 | 57.5 | 2 |
AJAX Separable Compressor
The environmentally friendly AJAX separable compressor has the economic advantages of an AJAX slow-speed compressor without the air quality permit issues related to an internal combustion engine.
Model | Stroke (in) | Rod Diam (in) | Rated Pwr (bhp) | Rated Speed (rpm) | Number of Throws | Con Rod Length (in) | GAS Rod Load (lbf) |
---|---|---|---|---|---|---|---|
C-202 | 11.000 | 2.500 | 200.0 | 455 | 2 | 23.750 | 33000.0 |
C-302 | 11.000 | 2.500 | 300.0 | 455 | 2 | 23.750 | 33000.0 |