F 250 2WD Pickup V8-351 5.8L (1982)
EGR Valve: Description and Operation
In this system the exhaust gases are reintroduced to the combustion cycle, therefore diluting the air fuel mixture entering the combustion chambers.
Dilution of the incoming mixture lowers peak flame temperatures during combustion and thus limits the formation of nitrogen oxides (NOx).
Fig. 46 Spacer entry EGR connection
Some engines use the ``Spacer Entry'' EGR System which has the EGR valve mounted on the carburetor spacer, Fig. 46. The exhaust gases are
taken from a drilled passage in the exhaust crossover of the intake manifold. The exhaust gas is then routed through a metered EGR valve to a
passage in the carburetor spacer and fed into the primary bore.
