Crank Case Pressure/Vacuum Theory

[RI Chevy]

Hmmm. Never knew if a 2 stroke diesel. Cool

 

[Marshy]

A 2 stroke Detroit diesel does not use atmospheric pressure to fill the cylinders - it uses a blower. The energy required to power the blower comes the energy stored in the diesel fuel, and released upon ignition/combustion.

I believe his point was the inlet of the induction system it at a positive pressure (atmospheric) and if it wasnt for that positive pressure ther would be no motive force for air to enter the turbo or intake tract. Ie. In a perfect vacuum no air would enter the engine regardless if it had forced induction or not.

 

[retro]

A 2 stroke Detroit diesel does not use atmospheric pressure to fill the cylinders - it uses a blower. The energy required to power the blower comes the energy stored in the diesel fuel, and released upon ignition/combustion.

Atmospheric pressure fills the Roots blower though, dusn'tit.

EDIT: Oops, @Marshy already said that.

 

[CJ Brown]

The 64 cent question is whether there can exist oxygen in a zero pressure environment.

 

[retro]

The 64 cent question is whether there can exist oxygen in a zero pressure environment.

The answer should be no... but finding a perfectly void environment might be difficult, even in space.

 

[CJ Brown]

Originally, I think I misinterpreted your post to say a blower cannot be used to create the pressure differential required to initiate the flow of fuel/air into a cylinder. I see you are actually saying a blower cannot be used to build a pressure differential in an environment devoid of matter. I agree with that.

 

[retro]

Originally, I think I misinterpreted your post to say a blower cannot be used to create the pressure differential required to initiate the flow of fuel/air into a cylinder. I see you are actually saying a blower cannot be used to build a pressure differential in an environment devoid of matter. I agree with that.

Correction: A blower cannot provide a pressure differential, due to the lack of pressure.

Ya gotta provide a force sufficient to supply the blower with air, else it will not work.

 

[CJ Brown]

If you planted an auger on an asteroid, and rotated it, would the auger self feed? Or would it require pressure to feed it?

 

[Clemsonfor]

2 stroke diesel???

Oh yea!! They scream and sound like there coming apart!! Sound like there turning 2x the RPMS they are!! They actually sound bad ass and are loud as Chit....Unless you have to drive one all day!!

Look up a two stroke Detroit on YouTube .

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[retro]

In space matter is limited (or much different than we experience & understand here on earth), but motion still occurs in space due to shock waves, solar radiation winds/storms etc.

 

[retro]

If you planted an auger on an asteroid, and rotated it, would the auger self feed? Or would it require pressure to feed it?

Once the auger got a bite it should self feed regardless of gravity (it is a screw), assuming the asteroid could be held still while the auger was rotated and the auger was capable of cutting the media.

 

[RI Chevy]

Oh yea!! They scream and sound like there coming apart!! Sound like there turning 2x the RPMS they are!! They actually sound bad ass and are loud as Chit....Unless you have to drive one all day!!

Look up a two stroke Detroit on YouTube .

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I just did. Really cool stuff. [emoji106]

 

[Marshy]

In space matter is limited (or much different than we experience & understand here on earth), but motion still occurs in space due to shock waves, solar radiation winds/storms etc.

Any talk about outer space officially marks a derailment.
Sticking with that...

 

[RI Chevy]

Cool

 

[Clemsonfor]

I am a Volunteer Fire Fighter for our county. Our ladder truck from the city fire dept is a 1970 something. It has a Detroit- two stroke in it. That thing is loud and screams!

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[Stump Shot]

I am a Volunteer Fire Fighter for our county. Our ladder truck from the city fire dept is a 1970 something. It has a Detroit- two stroke in it. That thing is loud and screams!

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But can it put out a fire in outer space.

 

[Clemsonfor]

But can it put out a fire in outer space.

Ladder is not quite that tall! Haha

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[Al Smith]

All 645 engines utilize either a Roots blower or a turbocharger for cylinder scavenging. The turbocharger (a combination turbo-compressor system) follows EMD's innovative design that uses a gear train and over-running clutch to drive the compressor rotor during low engine speed, when exhaust gas temperature (and, correspondingly, heat energy) alone is insufficient to drive the turbine. At higher engine speeds, increased exhaust gas temperature is sufficient to drive the turbine and the clutch disengages, turning the turbo-compressor system into a true turbocharger. The turbo-compressor can revert to compressor mode momentarily during demands for large increases in engine output power. While more expensive to maintain than Roots blowers, the turbocharger significantly reduces fuel consumption and emissions, while improving high-altitude performance. Additionally, EMD's turbo-compressor can provide a 50 percent increase in maximum rated horsepower over Roots-blown engines for the same engine displacement (2,000 hp or 1,500 kW for the Roots-blown 16-645, and 3,000 hp or 2,200 kW for the turbocharged 16-645, and similar increases for 12- and 8-cylinder 645s).---------it doesn't really explain how it starts except mention an over speed gear drive at low speeds .645 by the way is the displacement per cylinder in cubic inches .By comparison the submarine diesels were 16v 278 ,about 1400 HP at 800-850 RPM ,trivia .

 

[Marshy]

All 645 engines utilize either a Roots blower or a turbocharger for cylinder scavenging. The turbocharger (a combination turbo-compressor system) follows EMD's innovative design that uses a gear train and over-running clutch to drive the compressor rotor during low engine speed, when exhaust gas temperature (and, correspondingly, heat energy) alone is insufficient to drive the turbine. At higher engine speeds, increased exhaust gas temperature is sufficient to drive the turbine and the clutch disengages, turning the turbo-compressor system into a true turbocharger. The turbo-compressor can revert to compressor mode momentarily during demands for large increases in engine output power. While more expensive to maintain than Roots blowers, the turbocharger significantly reduces fuel consumption and emissions, while improving high-altitude performance. Additionally, EMD's turbo-compressor can provide a 50 percent increase in maximum rated horsepower over Roots-blown engines for the same engine displacement (2,000 hp or 1,500 kW for the Roots-blown 16-645, and 3,000 hp or 2,200 kW for the turbocharged 16-645, and similar increases for 12- and 8-cylinder 645s).---------it doesn't really explain how it starts except mention an over speed gear drive at low speeds .645 by the way is the displacement per cylinder in cubic inches .By comparison the submarine diesels were 16v 278 ,about 1400 HP at 800-850 RPM ,trivia .

I'm very familiar with the 645. We have three 20 cylinder 645-E's.
Here is a cool video of a 710 which is designed after the 645. Main difference is the electronic solenoid operated injectors. You can see the gear train for the blower.

Sounds like you have some experience with them also.

 

[huskihl]

Any talk about outer space officially marks a derailed.
Sticking with that...

I nominate this post for best in the thread.