why is rich better for power ??

[Robert Harris]

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????

"When some one gets something for nothing -
             some one else gets nothing for something "

If the first ingredient ain't Habanero, then the rest don't matter.
Robert Harris <bob at bobthecomputerguy.com>


----------
> From: James Weiler <james at brc.ubc.ca>
> To: diy_efi at coulomb.eng.ohio-state.edu
> Cc: diy_efi at coulomb.eng.ohio-state.edu
> Subject: Re: why is rich better for power ??
> Date: Friday, September 05, 1997 4:18 PM
> 
> 
> 
> On Fri, 5 Sep 1997, Tom Cloud wrote:
> 
> > can anyone out there tell me why stoich doesn't make the
> > best power ??
> 
> I thought stoich does give best power but you go a little rich for safety 
> reasons.  No?
> jw