Quote:
Originally Posted by wungun
I keep hearing about this Honda lean burn...
I call foul...
I think it's simply just ad copy to help sell cars, a nifty catch phrase.
We all know that an internal combustion four stroke gas engine needs a relatively specific fuel air ratio...
Runs it too lean and bad things happen....very bad things!
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One context with respect to 'lean burn' is that you're hard-pressed to initiate combustion.
HONDA's CVCC engine,with 3-valve head pre-combustion chambers allowed the spark plugs to light off a relative rich,but small local mixture,with the flame front propagating outward into the leaner,non-stoiciometric mixture.
With the V-TEC engines,HONDA is pulling off the same trick without the expensive castings and mechanicals.I believe that air-fuel ratios as lean as 21-1 can be achieved.Heat is an issue,so the otherwise 'inert' Nitrogen is reacting in to NOX,but the catalysts keep these emissions in check.