why is rich better for power ??

[Johnny]

Robert Harris wrote:
> 
> Try this thought pattern.  Gasoline is a blend of different chemicals -
> ranging from methanol, butane to toluene etc.  Generally speaking
> the lighter chemicals have higher latent heats of evaporation, octane,
> and quicker burning. The heavier chemicals generally contain more
> total energy but take longer to burn.  Sort of like kindling to logs.
> 
> By richening the mixture past stoich, more lights absorb more heat,
> thus cooler denser mixture.  They are also higher octane - more
> tolerance to detonation and they burn more uniformly faster. Kind of
> like a fast bonfire  - more heat, more power, big chunks (heavys) left
> unburnt. Over stoich means less efficiency - but higher power because
> of faster wasteful combustion with more heat.  Also complete combustion
> requires several stages which take time.  Rich mixtures generate more
> heat from early stages and less from the slower burning later stages and
> run out of oxygen and just throw away the slower heavys.
> 
> Now is every one confused????

No not at all. I got it... I just pull into the gas station and I say,
"fill-er-up, and give me the stuff that has lots of logs in it, not that
crap that's all kindling". ;)

BTW, the slower burning elements have the higher octane rating.

-j-