I will get started on the math and post pics of the papers soon, (it takes a good minute to perform these equations, if you've ever done one, you'd understand)
This is thermal velocity broke down
In this graph, assume that x-temperature
When a moving particle (air/fuel) inside the temp. gradient, collides with a medium (heat, or spark if you will) it will reach an equilibrium distrobution.
Now if you do your math on this, you will see the possible velocity in whcih, your "flame front" (as someone previously refered to as) will travel inside the combustion chamber.
BUT, there is still a variant that must be considered, the initial amount of heat. Thats where the rest of boltzmann's equation comes into play.
Just to my luck, someone has already made a nice little program that will graph the outcome, when more initial energy (heat) is introduced into the equation. Here is the link.
http://www.chemsoc.org/exemplarchem/entries/pkirby/exemchem/boltzmann/boltzmann.html