Thermactor Air Pump, Diverter Valve, Check Valve & Rail
Belt-driven rotary-vane air pump and 6-branch cylinder-head manifold that inject fresh oxygen to light off the catalytic converters.
Role in the System
What This Assembly Is
The Ford Thermactor (Thermal Reactor) secondary air injection system combines a belt-driven rotary-vane air pump, a vacuum-controlled combination bypass/diverter valve, one-way check valves, a 6-branch steel injection spider threaded directly into the cylinder head exhaust ports, and the Positive Crankcase Ventilation (PCV) valve.
Mechanics & Physics
How the Subcomponents Work Together
Cold-Start Port Oxidation vs. Warm Catalyst Feed: During the first two minutes after a cold start, the engine runs rich and the catalytic converters are too cold to work. The diverter valve routes fresh air from the rotary-vane pump through the 6-branch steel rail right into the hot exhaust ports—burning unburned hydrocarbons on the spot so the exhaust gases heat the catalysts rapidly. Once warm, the diverter switches air downstream between the two catalytic converter beds so the rear oxidation bed has fresh oxygen to convert CO and HC into harmless CO₂ and water.
Other Assemblies in This System
Split Front (Cyl 1–3) & Rear (Cyl 4–6) Exhaust Manifolds
Two separate nodular-iron 3-into-1 exhaust manifolds that eliminate thermal warping and scavenge paired 240° firing pulses.
EGR Valve, EVP Position Sensor & Stainless Exhaust Tube
Meters inert exhaust gas back into the intake manifold under part-throttle cruise to suppress peak combustion temperatures and NOx.
Dual-Stage TWC Catalytic Converters, Muffler & Tailpipe
Dual-branch Y-pipe, heated oxygen sensor, two-stage monolithic honeycombs, tri-flow muffler, and over-axle tailpipe.