Right then
I'm curious about injection angle, so here are a few questions.
At what angle does Vems initiate each injection period? does it inject at the missing tooth, therefore the angle is the same or similar to the 'Trigger before TDC' value in trigger settings?
within reason, what angle is suited to better Hydrocarbon emissions? Before inlet valve opens, or after?
I ask these questions as I am getting closer to having the engine running. I have mapped the inlet and exhaust cam lift. My initial thought is that injecting at the point the exhaust valve closes, will reduce the chance of unburnt fuel passing into the exhaust on valve overlap. However, another theory that fuel burns better after it has sat at th back of a closed inlet valve just before it opens, where it can evaporate off. Liquid fuel doesn't burn as efficiently, therefore hydrocarbon levels can increase? My thinking might be way off the mark
At this juncture, what sort of rough angle should I consider for good emissions, in relation to valve overlap. Obviously this changs with port velocities, which is why we now have the injection angle curve, but how does that affect when fuel should be injected. Do we inject at low rpm, close to the closure of the exhaust valve and then advance this as rpm increases? Obviously a 4 gas analyser will help, but I don't have one and the antiquated angine dyno I have use of, they don't have one either.
Obviously this is taking things one step further from just settling for whatever Vems decides to inject at, it's what we had to do before, but I do at least want to use the injection angle curve at some point in an effort to reduce Hydrocarbon emissions when I really do get a chance to play with it.
