.So most GEM blends with a large % of ethanol and methanol are going to have very low RVPs..
Yes, and so will high octane race fuels unless the fuel chemist has made adjustments.
Isopentane, neo-hexane, MTBE, various ethers, etc.What are the good ways that blenders add more appropriate RVP numbers for an NA engine?
It has a very low boiling point which helps cold weather operation, and has decent octane and high stoich value. But it boils at 31F deg.We know winter pump gas gets butane added (RVP = 52 PSI?) -but is that just because it's effective and
cheap or is it otherwise useful in the blend?
Aromatics are not very volatile at all.Volatile aromatics have to be called volatile for a reason... is this one of the big roles that Benzene, Toluene, and Xylene play?
Benzine =3.22psi
Toluol = 1.03psi
Xylene = 0.26, 0.33, 0.34psi
Injector atomization involves much more than RVP. We must consider spray pattern, droplet size, injection pressure, viscosity, injection velocity, tempertures, etc.And how much does RVP matter with fine atomizing port injectors, anyway?
In a slow running engine with a carb or throttle body injection, the fuel can tolerate higher front ends and higher tails.
In a high speed engine, or one with port injection, complete atomiztion can only be accomplished with a fuel composed of the correct components. A fuel for an injected engine running over 17000rpm is easily possible, i.e. F1.
We have constructed fuels for two stroke go-karts running at 18000rpm, with junk carbs.