I am seriously confused here. I had always been taught that rich mixtures burn faster than lean mixtures. I realize that there are many factors affecting burn speed, such as pressure, temperature, turbulence, and fuel octane, but still...

What I'm beating myself up over is this: I was flipping around on the net and I found several books and web sites claiming richer burns faster and others that claim leaner burns faster. No joke. See for yourself these two searches on google, and be sure to include the double quotes:

"rich mixtures burn faster"
"lean mixtures burn faster"

This is just an example of why I'm ripping my hair out. Does anyone have a definite answer for me? Perhaps an explanation of why a particular mixture burns faster? I already understand quite a bit of combustion dynamics but this is just rediculous. THANKS

 

Are you trying to tune a car or something? Richer or leaner from what point? Stoich? Very generic question. Usually anything on the south side of 13.5 is goin to give u best performance at wot. Cruising is a different story. I've seen part throttle tunes at lean as the 16's

 

No, I'm speaking relative to any mixture strength. i.e., as mixture gets richer, it burns faster. I understand that there are bounds either rich or lean where the mixture begins to burn much slower or becomes unburnable. But fairly close to stoich, which provides a faster burn rate? Richer or leaner mixtures?

How does the mixture strength affect the burn rate at all? I can understand burn rate relative to fuel octane and charge temperature, but the mixture strength boggles me.

 

Richer burns faster (up to a point).

 

Lean can burn faster too, but VERY lean, to the point of spontaneous combustion. Detonation pressure spikes are crazy looking in a graphical representation relative to
"normal combustion"

You are getting two answers because it can go both ways.