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Old 01-07-2011, 11:34 AM   #44 (permalink)
t vago
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Quote:
Originally Posted by abently View Post
Otherwise how/why do all other Lean-burn engines operate in the 20-25:1 AFR's?
The other engines you mentioned have direct gasoline injection. This enables them to do neat tricks, like inject just enough gas to make a super-lean mixture during induction, and inject a little more gasoline later on to create a stoichimetric pocket of air-fuel mix within the super-lean mixture, during compression. This gives a so-called stratified charge. The spark plug easily ignites the stoich pocket, and the burning pocket then goes on to reliably burn the rest of the super-lean mixture.

That's how you can get 20:1 to 25:1 AFRs with modern lean-burn engines.
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