3. Assuming all of the fuel can still be vaporized and combusted, it is prefferable to vaporize all of the fuel in the cylinder. The density of Gasoline is about 700 Kg/cm (kilograms per cubic meter) in the liquid phase and about 3.5 kg/cm in the vapor phase. Using the 70 deg. F change in air temperature given by Gary for vaporization temperature drop of the air and the ideal gas equation and assuming intitial air temperature of 350 Kelvin and a 14 to 1 air fuel ratio, we get the following equations:

 

Specific volume liquid fuel mixture =  (1 / 700 + 14 / 0.968) / 15 = 0.9643 cm/kg

 

Specific volume gaseous fuel mixture = ( 1 / 3.5 + 14 / 1.092) / 15 = 0.8714 cm/kg

 

Thus, 10.7 % more fuel mixture will fit into the cylinder if the fuel is in liquid form.

Ahem,

 

After glancing at what I wrote in Scott's reply, it would appear that a little self induced flaming is in order. Clearly, .8714 cm/kg is denser than .9643 cm/kg so the fully vaporized manifold mixture would increase the cylinder charge. I'm sorry for disagreeing with you Gary. Probably the result of a Monday morning haze.

 

I still challenge anyone to get it all vaporized before the valve without adding a really large heater or a really large runner!

 

Rob