On Feb 5, 9:35 pm, "Noddy" <m...@[EMAIL PROTECTED]
> wrote:
> "the_dawggie" <the_dawg...@[EMAIL PROTECTED]
> wrote in message
>
> news:9a26736e-1376-4e11-80cc-
>
> > 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.
>
> But it is.
>
> Diesel engines run incredibly high comrpession ratio's compared to your
> average SI engine, and by more than 50% in some cases, and this puts
> enormous load on things like rod and crack bearings, the crank itself
and
> the bearing caps. You also have a sustained high pressure for a longer
Mine is around 22:1 with a turbo taking up to 10 PSI.
After 225,000 km doesn't bother it. Thats with a turbo I bolted
on at around 35,000 km
Done some towing too - actaully a lot of it.
I'll be driving it tomorrow.
Oh, and it does not burn engine oil between cahnges.
Noddy, you got to do some
> period as the fuel is continually fed into the engine and burnt,
compared to
> a SI engine that has an initial peak pressure and then begins to taper
off
> almost immediately.
>
> > 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.
>
> The main difference in longevity between petrol & diesel engines is due
> mainly to the fact that diesel engines are very low revving "plodders",
and
> they don't produce much in the way of carbon deposits (which is the
number
> one killer of all petrol burning engines). That said, just because an
engine
> is an "oil burner" is no guarantee that it'll be reliable and long lived
as
> there have been plenty that have been problematic and led very short
lives.
>
> --
> Regards,
> Noddy.
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