Gas mileage and headers

[Guenther, Max [ASCO/PA]]

I'm not talking mpg, I'm talking WOT.  Power output per CID.  Alcohol does
allow higher compression, but not much higher than racing fuel.  I believe
the big gain in alky is the presence of oxygen,  and oxygen is the limiting
factor of any IC engine.  Even if BTU's per pound are less than non oxygen
enriched fuel, the density of liquid fuel does not begin to compare with the
density of air.  (even if alcohol is half the density of gas it more than
makes up for the BTU difference because it brings in O2).  

Just trying to make sure I have the concept down close to right.
Max

> ----------
> From:
> John_Calabrese at ENGELHARD.COM[SMTP:John_Calabrese at ENGELHARD.COM]
> Reply To: 	gmecm at diy-efi.org
> Sent: 	Thursday, October 26, 2000 10:43 AM
> To: 	gmecm at diy-efi.org
> Subject: 	RE: Gas mileage and headers
> 
> <<
> Does anybody know why oxygenated gas doesn't give you more hp???!
> Horsepower is a (rough) linear function of air(oxygen) through the engine.
> Its why we do sooooooooooo much better on alky.
> >>
> 
> It has to do with the BTU content of the fuel.  We don't do sooooo much
> better on alky, without sacificing mpg.  The btu content of alky is around
> 30000 kJ/kg, while gas is 47500.  We also do better on alky because it
> burns colder, and you can run higher compression, and almost need to run
> higher compression to get the burn rates high enough for optimum
> efficiency.  plus, the VE is increased with alchohol due to the high
> evaporative cooling, which cools the intake charge for more power as well.
> It really isn't a fair comparison
> 
> 
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