New diesel engines

[muddyboots]

As I understand it, the problem is that the PD engine can't be tweaked far enough to meet upcoming emissions requirements in the future.

In order to meet ever more stringent emissions rules, engine designers are having to do more exotic things, like injecting fuel into the exhaust stroke (don't ask me how that helps, but apparently it does).

But with PD, the injection pressure is only available while that plunger is pressing down inside the PD injector. That means it's only available at certain crank angles, because the PD injector is cam driven. So with PD you can only ever inject fuel near top-dead-centre between the compression and power stroke.

Common Rail maintains its pressure all the time, so the injectors can squirt fuel into the cylinders any time they like. It's a much more flexible system in that sense.

Very interesting post
Makes sense when you put it like that.

 

[sssstew]

yep, makes perfect sense.

 

[horace1664]

Also if a PD can't run on Bio fuels, (well the higher-powered versions can't), this would also make sense.
I would still like to know what this 2G0 kit for Bio fuels is apart from, presumably, a fuel heater.

James

 

[allh2k]

I noticed no one mentions the D4D toyota dervs r these any good or just part of the HDI movement.???

 

[basstard]

wow someone resurrected this thread!! [didn't receive no mail about it tho,,, ]

well, with time I understood [someone correct me if I'm wrong] that the new tdi's are both pd AND common rail in the sense that a single rail feeds the injectors at constant and even pressure then the fuel is pressurized even more by the pd system.

the cam issue pointed out makes me think,,, it makes sense but then the injectors have their own cams than can be profiled as needed,,,

as I see it the D4D engines are VERY good,,, not that high powered but bomb proof like all the jap stuff,,,

as for changing the car, maybe at the time I was being way too optimistic,,, the 3 years are over and I still got the beezer [she looks much better and shinier now so she seems younger than what it did at the time,,,] but I must admit the 120d is very tempting: the 3 doors version looks even meaner than the 5dr, the engine is 163hp on the 5dr but should be more powerful on the 3dr [don't ask me why] and most of all, they're rwd,,, kinda costy but I reckon a german import will do the job,,, we'll see,,,

 

[Fl@pper]

with road taxation going through the roof lately it was nice to see a cotroen c3 s.5 tdi today £35 a year tax lol

mines £90 odd just for 6 months - oh the joy though

 

[basstard]

I just dread to think of how the V8 will get taxed,,,

 

[allh2k]

o yeah another derv is the honda one no mentions him too!!