[saurabhkanchan]

also can you clarify what type of pump is used in the fuel oil system? there is a return line connecting the pump with the fuel tank, what is that for?

[saurabhkanchan]

niteshbids, in one of the earlier posts you had mentioned about piezo injectors, can you give some information regarding the same? how are they different from regular injectors?

[niteshbids]

The fuel pressure in the rails and the injectors are in the range of 1200 to 1800 bars in general applications. There have been engines in which the pressure goes as high as 2400 bars, though i don't know exactly which one it is.

I'm not aware of any separate overflow tank for the fuel. I really don't see the point, but maybe there is something. or maybe the Scorpio owner was confusing some other part. Not sure..

[niteshbids]

Originally Posted by saurabhkanchan

also can you clarify what type of pump is used in the fuel oil system? there is a return line connecting the pump with the fuel tank, what is that for?

Don't know the exact type of pump used. All i can say is that it is a mechanically driven pump driven by the engine.

Originally Posted by saurabhkanchan

niteshbids, in one of the earlier posts you had mentioned about piezo injectors, can you give some information regarding the same? how are they different from regular injectors?

The main difference is the method of actuation. Instead of regular solenoids, the piezoelectric injectors use piezoelectric crystals for the actuation which have much faster response time (upto 5 times faster) allowing for more accurate metering of the fuel. The higher accuracy also allows for higher pressures which in turn give better atomisation.

Better atomisation and accurate metering result in less unburnt particles, lesser emissions and better efficiency.

[niteshbids]

Originally Posted by saurabhkanchan

there is a return line connecting the pump with the fuel tank, what is that for?

Sorry, missed this part in my earlier reply - The return line is same as the one coming from the common rail as well. The idea behind it is that wherever there is any excess pressure and needs to be released, there needs to be a provision for it.

[Sutripta]

Originally Posted by saurabhkanchan

niteshbids, in one of the earlier posts you had mentioned about piezo injectors, can you give some information regarding the same? how are they different from regular injectors?

Hi,
By regular injectors do you mean the older non CR implementation? If so, these are entirely different. Injectors for CR systems are controlled by a electrical signal. These don't pop under fluid pressure.

Regards
Sutripta

[niteshbids]

By regular injectors, I reckon he means the more commonly used solenoid based injectors currently used in most cars running on common rail engines. The piezo injectors are still uncommon as they are significantly more expensive than the solenoid based ones

[Sutripta]

Originally Posted by niteshbids

Don't know the exact type of pump used. All i can say is that it is a mechanically driven pump driven by the engine.

Radial piston pump.

Regards
Sutripta