U.S. EPA Heavy-Duty Engine 

Compliance Testing Setup Requirements
EPA-420-B-10-004

February 2010

Compliance and Innovative Strategies Division

Office of Transportation and Air Quality

U.S. Environmental Protection Agency

U.S. EPA Heavy-Duty Engine 

Compliance Testing Setup Requirements
U.S. EPA Heavy-Duty Engine Compliance Testing Setup Requirements 

 

1. Engine must be supplied with matching turbo-to-exhaust flange and appropriate clamp. 

2. Engine must be supplied with a detailed drawing, including dimensions, of front and rear 

mounting pads. 

3. Engine must be supplied with a standard SAE-type bell-housing. 

4. A dynamometer flywheel adapter plate must be supplied with the engine. This adapter must 

be machined to the specifications in Figure 1. 

5. A wiring harness (min. 8 ft in length) must be supplied with the following test-cell interfaces; 

all wires must be clearly marked: 

a. 0-5 Volt (DC) throttle signal input 

b. ECM Power input 

c. Diagnostic port (SAE J1939 preferred) 

d. Vehicle speed sensor input (if required) 

6. The manufacturer must supply software, data link, and laptop computer for engine diagnostic 

purposes as well as a description of any codes that may be expected when testing in the lab. 

7. The rotational inertia of the engine, with the flywheel attached, must be supplied. 

8. Fuel inlet and return ports should have a JIC fitting, sized appropriately by the manufacturer. 

9. Temperature Instrumentation - The following locations must have a 1⁄4” NPT boss (for 

installation of a thermocouple) and be clearly labeled: 

a. Oil sump 

b. Coolant in 

c. Coolant out 

d. Fuel supply 

e. Fuel return 

f. Turbo (compressor-side) out (charge-air cooler inlet) 

g. Intake manifold inlet (charge-air cooler outlet) 

h. Turbo (turbine-side) out (engine-out exh temp; only if A/T equipped) 

i. Exhaust aftertreatment inlet (if equipped) 

j. Exhaust aftertreatment core (if equipped) 

10. Pressure Instrumentation – The following locations must have a -4 JIC fitting installed: 

a. Oil galley 

b. Turbo compressor out 

c. Intake manifold 

d. Fuel supply 

e. Fuel return 

f. Engine block coolant passage (to measure block coolant pressure) 

 
 

11. The engine must be supplied without an air pump or with the air pump disabled. Any 

necessary block-off plates must be installed. 

12. The front accessory drive should have the minimal number of devices to allow the engine to 

function correctly. If accessories are required, they should be supplied with all the support 

equipment required to operate and maintain them. 

13. The turbo compressor outlet and intake manifold inlet should have adjustable elbows that 

allow for changes in rotational orientation. If these elbows are fixed, they should both point 

straight forward. 

14. Engine air inlet (or inlet to turbocharger) should be located above the valve cover. The inlet 

should be oriented vertically and allow for attachment of a 5” or 6” rubber hose. 

15. If crankcase emissions are not routed to the intake manifold, a blow-by hose and all associated 

hardware required for attachment must be supplied. 

16. Aftertreatment Requirements:

a. The space available for aftertreatment devices is approximately 4’ x 7’, (see Fig 2) 

b. The aftertreatment system must be less than 75” in height 

c. The aftertreatment system must have one inlet and one outlet 

i. Both must have appropriate flanges affixed to both ends 

d. All aftertreatment devices must be supplied with, and maintained by, their own 

ECM(s) or the engine ECM 

i. All necessary wiring must be supplied and labeled accordingly 

ii. Wiring between the aftertreatment system and engine ECM should be at least 8’ 

in length 

e. DC Power is available from 0-30 V and 0-50 A 

f. All systems must be freestanding (should not have to be affixed to the floor) 

g. For DEF-SCR systems, all required handling systems (pumps, tank, hoses, wiring, etc) 

must be supplied and connections labeled appropriately 

h. A setup drawing must be supplied that shows the recommended location of the 

aftertreatment system (within the space shown in Fig 2) as well as suggested wire/hose 

routing and connection points 

i. If the aftertreatment system requires DEF, the manufacturer must provide 

commercially available DEF in sufficient quantity for testing 

i. The administrator reserves the right to conduct the test using either the 

manufacturer-supplied DEF or any other DEF meeting the specifications of ISO22241 

ii. Please include the MSDS when sending the DEF 

j. Please include instructions for identifying when regeneration events are occurring, 

approximate duration of such events, and other relevant information related to testing 
-EPA uses a Dana-Spicer 1810 driveshaft flange. This flang

Flywheel Adapter Specifications -EPA recommends the adapter be made from *Drawing not to scale 

A-A 

0.75”

16 Equally-spaced bolt holes, drilled and tapped for a 7/16”-20 UNF thru-bolt (for driveshaft flange attachment) 

A-A Sectio

12 Equally-spaced thruholes (7/16” bolt clearance) at 16.63” bolt circle (for flywheel attachment) 

3.751”-

3.753” 0
Bedplate 

Engine Pallet 

Wall 

Aftertreatment 

Area 

Dynamometer 

4 ft 

7 ft 

7 ft 

Figure 2 Test Cell Aftertreatment Space