This is insane (PD diesel topic)

[moribundman]

I read the fuel injection pressure on a PD diesel engine was up to 2,400 bar. That's almost a whopping 35,000 psi! Higher pressure means better atomization of fuel and thus better efficiency.

 

[k1xv]

They say if you crack open a connection while the thing is pressurized and it sprays you, the oil goes right through your skin. I believe my GMC Duramax operates somewhere way up there in pressure.

 

[simple_gifts]

quote:

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Originally posted by k1xv: They say if you crack open a connection while the thing is pressurized and it sprays you, the oil goes right through your skin.

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Ah, brings back memories of military immunizations, except they used vaccine, not diesel fuel!

 

[Kestas]

Some modern designs now incorporate a camshaft that pressurizes individual hydraulic buckets for a momentary burst of high pressure fuel in each cylinder. We had one such design come through our lab.

 

[moribundman]

It appears that the PD cam-activated injector unit contains a small piston assembly and a solenoid that relases the fuel. The soleniod also releases a couple cubic mm fuel, a "pilot injection," before injecting the main amount. This makes combustion smoother, improves effciency, and makes the engine sound quieter. The basic idea of direct injection goes back to Rudolf Diesel himself in 1905!

 

[Shannow]

The M-Fire injection in my Nissan works at up to 100MPa, a mere 1000 bar (145,000psi), and when at light throttle introduces a small amount of fuel to heat the chamber gasses, and then the main bulk. Some of the European engines have around 10 individual injection events in a single cycle. My 950,000hp steam turbines only run 2500psi.

 

[ekpolk]

quote:

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Originally posted by k1xv: They say if you crack open a connection while the thing is pressurized and it sprays you, the oil goes right through your skin. I believe my GMC Duramax operates somewhere way up there in pressure.

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The jet I flew back in my aviation days (the EA-6) has a 3000 psi hydraulic system. We were taught to treat it with the utmost respect. Any time you approached a running jet (or one hooked up to a hyd cart) or opened a panel, you were to look for a pink mist or cloud (milspec hyd fluid is cherry colored). If you saw this, you just went the other way, quickly. The 3k pressure is enough to cut skin like a blade, when in a tight stream or to auto-inject, like a bulk immunization device. I can only imagine (not a pretty picture) what 35k psi (10x plus) is going to do the few unfortunate, untrained fools who mess around improvidently under the hoods of their diesels. . .

 

[moribundman]

I hope there are warning labels on high pressure hoses, fittings, and parts...

 

[Brikhead]

Audi's new 'FSI'(2.0T & 3.2) gas engines also operate with similar high fuel inj. pressures.

 

[Willy_G]

As little as 100 PSI will permeate skin. 35000 PSI will cut your finger off before you know it!