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Old 01-07-2008, 08:46 PM   #29 (permalink)
Frank Lee
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Blue - '93 Ford Tempo
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Quote:
Originally Posted by roflwaffle View Post
Old domestics had a spring/flap on the exhaust for warm up, old skool internal EGR I guess. The flap would stay closed'ish and not all the hot gas would exit the combustion chamber until the manifold warmed up enough/the spring rate dropped enough and the flap popped open.
Guess again. The thermostatic flaps closed up when cold to route hot exhaust through passages in the intake manifold, to heat the carb. They did not restrict exhaust enough for any EGR action.
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