On Feb 5, 9:55 am, Athol <athol_SPIT_S...@[EMAIL PROTECTED]
> wrote:
> the_dawggie <the_dawg...@[EMAIL PROTECTED]
> wrote:
> > Petrol makes me barf, I can't stand the smell of it.
>
> I can't stand the smell of petrol or diesel, and I was actuially
> saying to my wife last night that I don't know which one is
> worse. They are both disgusting but in different ways.
>
> > I have an issue for Node about how a diesel engine works.
> > They are more a plunger effect than hit with hammer SI
> > effect. I know that, and it's more than obvious. Athol too
> > should know that. It's one of the most basic facts of diesel
> > engines. Petrol bangs, diesel burns.
>
> What garbage. The difference is flame propogation speed in a
> controlled burn. Pre-ignition (where the whole lot spontaneously
> explodes and a spark ignition engine sounds like a diesel) is a
> *fault* situation involving explosion instead of controlled burn.
I don't understand how you or Node get this wrong.
Diesels have a longer total burn time as once the burn is started the
injection
continues for 20 degrees or more of the crank's rotation. This results
in lower
overall piston and rod loads due to a lower peak combustion pressure
but greater
average pressure per stroke. Intuitively this SOUNDS like double talk
(violent initial
combustion noise) but it's really not if you study the process
carefully.
This basic difference between SI & CI combustion is the main reason
for the longer service life of Diesels engines, along with the other
benefits of leaner stratified combustion and them being better suited
for turbo charging, due to lower EGT's & no detonation concerns. Also
with no air throttle a Diesel's turbo can actually be useful during
normal driving.
I understand petrol engine pre-ignition, that is not what I'm typing
about.
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