Gasoline is quite difficult to ignite as a liquid, in fact it's only combustible in vapor form. The fuel injectors spray fuel as small droplets which have smaller surface area than a homogeneous squirt of liquid fuel, this aids vaporization, and by consequence combustion. Heating fuel aids this vaporization, the problem with heating fuel excessively in the rail is that you can get vapor lock, then you get nothing. That's why using residual EGR to heat the fuel as it's injected is a viable strategy.dren wrote: ↑31 May 2017, 15:19There is fuel heating prior to injection, and then there is the chance of pre-ignition due to early injection because it's exposed to the hot chamber longer. Maybe the fuel type is fine in the condition?godlameroso wrote: ↑31 May 2017, 13:59Isn't fuel heating necessary? Regardless I believe there are multiple injections per cycle. As far as the timing is concerned, I imagine that's one of the more closely guarded secrets.Tommy Cookers wrote: ↑31 May 2017, 13:29
does injection continue after the spark ?
is there one injection episode or multiple episodes (per cycle) ?
(starting injection 90 - 180 deg before the spark seems so old-fashioned and exposes the fuel to heat for a critically longer period ??)
The process is probably simpler than we're thinking, just hard to get to work in a controllable fashion.
Here's some dork showing how fuel doesn't really burn in liquid states. Gasoline is at 9 min mark.