The "Otto-cycle" engine is, basically, a heat engine.... That means that
there is no explosion in the cylinder or any magic, for that matter...
The ideal (stoichiometric) ratio for gasoline fueled engines is roughly 14.7
to 1 by weight. Now... the reason for this is for nothing more than
combustion efficiency. If the mixture is much richer, there is not enough
oxygen available to react the gasoline delivered...... similarly, if the
mixture is too lean, flame propogation slows down and, since there is too
much space between fuel molecules, there is a very good chance that there
will be unreacted fuel after the combustion event. Anyway... back to the
Asthe fuel and oxygen react in the combustion chamber, the other 70 some-odd
percent of the air is being rapidly heated and expands quickly.... driving
the piston down in the cylinder. It is the amount of heat released during
the combustion process that is the key to the operation of thees engines.
There is a finite amount of heat energy contained in one pound of gasoline.
Interesting to note that your article states that methane and alcohol are
"more powerful".... methane is just plain explosive and alcohol as (IIRC)
roughly half the BTU content of gasoline..... meaning we are going to
consume nearly twice as much alcohol as gasoline just to do the same work.
We'll leave out the fact that that methanol is corrosive... just ask any
alcohol racer that hasn't flushed his fuel system and changed his engine oil
after a race.
FWIW... diesel has a higher BTU content but it is unsuitable for spark
ignition engines.... It doesn't atomize well at the low pressure drops found
in carburettors and can create a lot of grief due to sooting and carbon
deposits. If we look closely, diesel engines do not use a throttle plate
(except for a very few EGR equipped diesels where an electronically
controlled throttle plate was installed to assist EGR operation). Taking
that a step further, we start to realize that a diesel cannot have either a
rich or lean mixture (and we wont get into "overfuelling" at this time).
If your Grandpa was as smart as you figure, he would have known that
tetraethyl lead had been added to gasoline as an octane improver (with the
added benefit of lubricating valve surfaces) since Gawd knows when.
FWIW, tales of the Pogue carburettor surface from time to time.... usually
presented as someone close to the writer to give an air of familiarity with
the device. Less common are tales of exotic looking engines (still working
on the Otto premise of "suck/squeeze/bang/blow) utilizing less efficient
scotch yokes and/or other devices to turn reciprocating motion into
For now, we will remain being slaves to the Ottocycle engine and the heat
content of available fuels....
For inciteful.... you get a D-..... for grammar and spelling, a B+..... for
originality you get a "get lost you plagiarist bastuhd...".