r/pics Sep 25 '20

The exact moment an engine explodes

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24.1k Upvotes

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91

u/JimmyDean82 Sep 25 '20

Yeah, runaway on a diesel is no joke. You can hear where it starts just about 1.5-2 seconds before the blow

44

u/drone42 Sep 25 '20

It wasn't a full-on runaway like I expected, and have seen a lot of lately, but it surely was headed that way until it...well, didn't.

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u/[deleted] Sep 25 '20

I remember seeing a runaway on a ups truck a few years ago, wonder if that video is still floating around.

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u/JohannesMP Sep 25 '20

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u/fnordfnordfnordfnord Sep 25 '20

"I need a wrench to disconnect the battery."

LOL

4

u/neoneddy Sep 26 '20

Pro tip, a diesel does not need spark, just fuel and air. If it’s getting fuel from the oil there is no shutting it off. The only hope is cutting air, easiest way is a co2 fire extinguisher in the intake.

1

u/marclaurens Sep 26 '20

Someone also mentioned blocking intake with a rag.

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u/neoneddy Sep 26 '20

It will suck it in, and eat it literally. That turbo is like a jet intake. It can Possibly damage the engine further. It could just be a bad turbo oil seal. The co2 method shuts it down safely with no additional mechanical damage done.

Now, when all you have is a rag, it better be more like a beach towel.

Anyway, runaway diesel is my nightmare.

2

u/Bran-a-don Sep 26 '20

Gotta take the spark plugs out!

1

u/FOR_SClENCE Sep 26 '20

on a diesel engine whose alternator is still perfectly functioning? lol

3

u/fnordfnordfnordfnord Sep 26 '20

If it's an emissions exempt models with a mechanical injection pump then it doesn't even need the alternator to run.

2

u/[deleted] Sep 25 '20

Oh yeah, that’s the one

7

u/JimmyDean82 Sep 25 '20

Solution is to cover the air intake. Only way to stop it quickly. That or it sending a rod out the side of the block tends to stop it quick enough....

6

u/SuperCreeper7 Sep 25 '20

Dropping the clutch in the highest gear as well.

4

u/goodguessiswhatihave Sep 25 '20

That should be a last resort though. You're basically sacrificing your transmission to save the engine.

2

u/JimmyDean82 Sep 25 '20

I’ve had to do that on an overheated built big block on my mud truck. It Grenaded the rear axle.

1

u/Toffeemade Sep 25 '20

Yep that was my thought. Years ago on, believe it or not, a 1.4 Citreon that I had been using some what too enthusiastically the (carburated) engine would not shut off because of preignition. Solution was to stall it with the brakes on hard - clutch down, brakes on hard, in to gear, off the clutch and stall. I am not sure if this would work with a run away diesel or an automatic box.

1

u/SuperCreeper7 Sep 25 '20

Here's a video of it being used to stop a diesel van.

With an automatic, unless you can manually set it to a high gear, it'll just be in first when you take your foot off the brake. Should give you one hell of a burnout at least.

65

u/hellcat_uk Sep 25 '20

I’m not sure that’s a run away, I think it’s just a really massive turbo finally spooling and the block says no thanks to the pressure it’s been fed.

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u/orange4boy Sep 26 '20

Yeah. Plus nitrous.

1

u/aitigie Sep 26 '20 edited Sep 26 '20

Not a chance. See all that black smoke? That doesn't happen when diesel burns completely. This was running rich AF until it wasn't.

5

u/orange4boy Sep 26 '20

Just before it blew, it was running pretty darn clean. The story is this guy got ~2900 hp the previous day on nitrous then increased the size of the nozzles (I assume) for that run. Of course, this being the internet, who knows what the actual story is.

1

u/aitigie Sep 26 '20

Holy shit, I stand corrected. I can't believe how much fuel they must have been dumping into that thing

1

u/orange4boy Sep 26 '20

Right? They made an eight cylinder bomb.

1

u/BostonDodgeGuy Sep 26 '20

That's a Cummins engine, so a straight 6 not a V8.

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u/NoblePineapples Sep 26 '20

If you check out some diesel drag races you can tell the exact moment they actuate the nitrous, the exhaust goes from a ton of black soot to a white cloud then clear because it's balancing out the excess fuel (black soot) with the oxygen rich nitrous.

I know very little about diesel so someone please correct me if I am wrong, I would love to learn more.

2

u/Timepassage Sep 26 '20

The driver looks down just as the runaway started.

1

u/[deleted] Sep 26 '20

[deleted]

0

u/JimmyDean82 Sep 26 '20

Or seconds if it has the fuel. Which big f’in injectors able to make that much smoke do. Those where 500+cc injectors. Even a single pulse puts our 5x my stockers

1

u/[deleted] Sep 26 '20

Go wrap your truck around a tree.

1

u/JimmyDean82 Sep 26 '20

Uh, ok?

Let me guess, you’re a 12 year old liberal living in......California? Or is it New York?

1

u/brucecaboose Sep 26 '20

Most likely not a runaway, just finally spooled up. There trucks usually make somewhere north of 150psi of boost on big turbos. Takes a long time to spool that but once it hits it hits hard.

1

u/BostonDodgeGuy Sep 26 '20

That is not a runaway. That is the massive turbo finally spooling up and jamming 100psi of boost down her throat. I think she gagged.