Emissions Control Devices

M-Block 351M/400 Parts ReferenceEmissions Control DevicesCopyright © 2002-2003 Dave Resch
All rights reserved.

Letter of permission on hand, thank you Dave Resch  ~BlizzND

 


This section lists Ford part numbers and ID codes for the following M-block (351M/400) emissions control devices:

  • Thermactor AIR (air injection reaction) pump, check valve, and backfire diverter valve
  • EGR (exhaust gas recirculation) valve and EGR spacer plate
  • PCV (positive crankcase ventilation) valve
  • Air cleaner heat stove vacuum motor
  • Air cleaner temperature sensors

 

 

Some other emissions control and related devices, and engine calibrations, are listed in the Carburetors and Fuel System Parts and Ignition System Partssections.

Check out this section if you are not familiar with Ford part numbers and ID codes.

Thermactor pump and check valve

The name “Thermactor” is Ford’s trademark brand name for the emissions control system known generically as AIR (air injection reaction).

The function of the AIR system is to blow fresh air into the exhaust gas stream. There are two benefits of this system:

  • Fresh air blown into the exhaust gas, just downstream of the exhaust ports, provides oxygen (O2) to promote further combustion of any remaining unburned hydrocarbons (HCs) in the exhaust gas.
  • Catalytic converters require additional oxygen to convert the carbon monoxide (CO) and hydrocarbons in exhaust gases into carbon dioxide (CO2) and water (H2O).

 

The Thermactor AIR system for M-block engines consists of the following components:

  • Thermactor pump — a simple vane-type air pump driven by a belt on the front of the engine
  • Thermactor backfire diverter valve — a vacuum-controlled valve that diverts air pump output to the atmosphere to prevent backfiring under high manifold vacuum (i.e., closed throttle) conditions
  • Check valve — a one-way valve downstream of the air pump and diverter valve that prevents exhaust backpressure from pushing hot exhaust gases back up into the AIR components

 

In addition to the Thermactor AIR components, two of the main cast parts of the engine have special provisions for the AIR system:

  • Intake manifold — a threaded port for the check valve and a dedicated AIR distribution passage in the front of the ’75-up M-block intake manifold deliver fresh air from the Thermactor pump to AIR passages in the cylinder heads.
  • Cylinder heads — AIR passages in ’73-up M-block and 351C 2V cylinder heads, including holes drilled into the intake side on each end of the cylinder head, a long passage drilled lengthwise through the cylinder head (just above the exhaust ports), and corresponding holes drilled from the exhaust ports into the long passage. These allow fresh air to be injected directly in the exhaust ports by the Thermactor AIR system.

 

The following table lists Thermactor AIR pump (smog pump) and check valve service part numbers for ’77-up M-block truck engines.

Description Part Number Notes
Thermactor pump E1TZ-9A486-D OEM repl. All ’77-’81 351M/400 truck, except ’79 CA emissions.
Thermactor pump E7TZ-9A486-J OEM repl. ’79 351M/400 truck w/ CA emissions, all ’82 351M/400 truck.
Thermactor check valve D7AZ-9A487-A OEM repl. All ’77-up 351M/400.
(Motorcraft CX-103)

Thermactor backfire diverter valve

The Thermactor backfire diverter valve was also referred to as the “AIR bypass valve” in some Ford technical literature. On some vacuum system diagrams, it is labeled “AIR BPV” or just “BPV.”

The following table lists Thermactor backfire diverter valve service part numbers for ’77-up M-block truck engines. Both Ford and Motorcraft part numbers are listed, when available.

Note: Many of these part numbers are obsolete, however, some are still available from either regular Ford dealers or obsolete parts sources.

Description Part Number Calib. ID Notes
Thermactor diverter valve D4AZ-9B289-A D4AE-AA (obsolete)
Thermactor diverter valve D4OZ-9B289-A D4OE-AA (obsolete)
Thermactor diverter valve D4TZ-9B289-A D4TE-AA (obsolete)
Thermactor diverter valve D4VY-9B289-A D4VE-AA (obsolete)
Thermactor diverter valve D5AZ-9B289-C D5AE-CB (obsolete)
Thermactor diverter valve D5DZ-9B289-A D5DE-AA (obsolete)
Thermactor diverter valve D5TZ-9B289-B D5TE-AA
D5TE-AB
(obsolete)
Thermactor diverter valve D5UZ-9B289-A D5UE-AA (obsolete)
Thermactor diverter valve D5ZZ-9B289-E D5ZE-EA (obsolete)
Thermactor diverter valve D6TZ-9B289-A D6TE-AA (obsolete)
Thermactor diverter valve D7TZ-9B289-B D7TE-BA (obsolete)
Thermactor diverter valve D8TZ-9B289-A D8TE-AA (obsolete)
Thermactor diverter valve E1TZ-9B289-C E1TE-CA
E1TE-GA
Current service part.
(Motorcraft CX-560)
Thermactor diverter valve E1ZZ-9B289-A D5ZE-FA (obsolete)
Thermactor diverter valve E3TZ-9B289-G D8BE-BA
E1TE-DA
Current service part.
(Motorcraft CX-938)
Thermactor diverter valve E3TZ-9B289-F D8BE-DA Current service part.
(Motorcraft CX-221-B)
Thermactor diverter valve E3TZ-9B289-E D8EE-AA
E1TE-EA
Current service part.
(Motorcraft CX-222-A)

EGR valve and spacer plate

The following table lists EGR valve and EGR spacer plate part numbers for ’77-up M-block truck engines. Motorcraft part numbers are listed, when available.

Note: Many of these part numbers are obsolete, however, some are still available from either regular Ford dealers or obsolete parts sources.

Description Part Number Notes
EGR valve D8DE-9D475-C1A
D8DE-9D475-C2A
’80-up 351M/400 truck.
(obsolete)
EGR valve D8DZ-9D475-C ’80-up 351M/400 truck.
(obsolete)
EGR valve D8DZ-9D475-CA All ’80-up 351M/400 truck.
(Motorcraft CX-301-A)
EGR valve D8TE-9D475-A1A
D8TE-9D475-A2A
’78 351M/400 truck, auto trans, CA emissions. ’79 351M/400 HD truck, 49-state.
(obsolete)
EGR valve D8TE-9D475-AA ’79 351M/400 HD truck, 49-state.
(obsolete)
EGR valve D9TE-9D475-C1A
D9TE-9D475-C2A
’78 351M/400 truck, auto trans, CA emissions. ’79 351M/400 HD truck, 49-state.
(obsolete)
EGR valve D9TE-9D475-CA ’79 351M/400 HD truck, 49-state.
(obsolete)
EGR valve E0AE-9D475-C1A
E0AE-9D475-C2A
’80 351M LD truck.
(obsolete)
EGR valve E3UE-9D475-A1A
E3UE-9D475-A2A
’78 351M/400 truck, auto trans, CA emissions.
(obsolete)
EGR spacer plate D7TE-9A589-A All ’77-’82 351M/400 truck.
(obsolete)

PCV valve

The following table lists PCV valve part numbers for ’77-up M-block truck engines. Both Ford service part and Motorcraft part numbers are listed.

Description Part Number Notes
PCV valve D7AZ-6A666-A All ’77-’78 351M/400 truck.
(Motorcraft EV-93)
PCV valve D9OZ-6A666-A All ’79-up 351M/400 truck.
(Motorcraft EV-68-C)

Air cleaner heat stove vacuum motor

On M-block engines, the air cleaner heat stove consists of a sheet metal shroud around the right (passenger side) exhaust manifold, and flexible, corrugated tubing from the shroud to the bottom of the intake snorkel on the air cleaner housing. When vacuum is applied to the heat stove vacuum motor, the motor moves a diverter flap inside the snorkel to close off the normal cold air intake and open up the heat stove warm air intake.

The vacuum motor is controlled by a temperature sensing vacuum switch inside the air cleaner housing (the ACTS, described in the next section).

The following table lists air cleaner heat stove vacuum motor service part numbers for ’77-up M-block truck engines. Motorcraft part numbers are listed where available.

Description Part Number ID Code Notes
Vacuum motor D7AZ-9D612-C ’82 351M HD truck.
(Motorcraft CX-149)
Vacuum motor D7TZ-9D612-B brown ’77-’81 all 351M/400 truck. ’79 351M car w/ high-altitude. ’82 351M LD truck. ’82 400, auto/manual trans, CA/49-states.
(Motorcraft CX-120)
Vacuum motor E2ZZ-9D612-A ’77-’79 some 351M/400 truck w/ CA emissions. ’79 351M car w/o high-altitude. ’82 400, auto trans, 49-states.
(Motorcraft CX-762)
Vacuum motor D9FZ-9D612-A pink ’82 400, auto/manual trans, CA/49-states.

Air cleaner temperature sensors

There are three different air temperature vacuum switches that Ford used in air cleaner housings:

  • ACTS (air cleaner temperature sensor) #9E607
  • TVS (temperature vacuum switch) #9A995
  • CWM (cold weather modulator) #9E862

 

The ACTS (9E607) is a thermostatic vacuum switch with a metal housing. The TVS (9A995) and CWM (9E862) are thermostatic vacuum switches with plastic housings. Calibrated open/close temperatures for these devices are indicated with color coding on the housing.

The ACTS controls the air cleaner heat stove vacuum motor by reacting to the air temperature inside the air cleaner housing. When the air temperature drops below the calibrated opening temperature of the ACTS, the valve inside the ACTS opens, supplying manifold vacuum to the air cleaner heat stove vacuum motor.

When the heat stove vacuum motor closes the diverter flap inside the intake snorkel, the engine draws intake air through the air cleaner heat stove system. When the engine has run a few minutes after a cold start, radiant heat from the exhaust manifold warms up the air drawn through the shroud, and the heat stove system supplies warm air to the engine.

When the temperature of the air inside the air cleaner housing exceeds the calibrated opening temperature of the ACTS, the valve inside the ACTS closes, cutting off the vacuum source (manifold vacuum) and bleeding the residual vacuum in the hose and the vacuum motor diaphragm. When vacuum is released from the vacuum motor diaphragm, an internal spring in the motor pushes it back to its rest position, which returns the intake snorkel diverter flap to its normal position for cold air intake.

The following table lists ACTS service part numbers specified for 1977 to 1982 M-block truck engines. Motorcraft part numbers are listed where available.

Air Cleaner Temperature Sensor #9E607
Ford Service P/N Motorcraft P/N Color Code Notes
D0ZZ-9E607-B blue All 351M/400.
105°F min. open
D4FZ-9E607-B CX-1384 green All 351M/400.
105°F min. open
D4ZZ-9E607-A yellow All 351M/400.
105°F min. open
D7DZ-9E607-A CX-146 ’82 351M/400.
D7FZ-9E607-A CX-109 brown All 351M/400.
75°F min. open
D8TZ-9E607-A white All 351M/400.
90°F min. open
Color codes and specifications for 9A995, 9E607, and 9E862 air temperature vacuum switches are listed on this page.

Parts Home

M-Block Home

Leave a Reply