50,000rpm 2021 Jeep

Apis Mellifera said:

In reply to Toyman01 (Moderately Supportive Dude) :

Ok, I couldn't hear well, but heard "converter" and assumed.  Still though, the grip from the tires?

The point of having four wheel drive is the grip!  (IIRC, Jeep does not put front axle disconnects on Wranglers, so no worries about the front axle being disengaged)

Another way to look at it.  It could not reasonably have taken any more power to do that than a motorhome's engine makes, right?  If they could get it moving, they could get it exploding.

APEowner said:

I suspect the flywheel blew apart as they were coming up to speed.

Not before the engine came apart.  Once the flywheel exploded, the engine would have stopped turning.

I mean, the bottom end probably made like the Kool-Aid Man at around 9000-10,000, so the flywheel would have had to come apart even higher than that.

And the rods letting go USUALLY doesn't result in the crank snapping, so the now-imbalanced crank probably let go somewhere between the rods setting sail and the leftover rod chunks scything through the block, and the flywheel exploding.

Of all the times to not have a GoPro mounted under a vehicle!

I wonder what the people behind that Jeep thought as it sawed itself in half. I imagine they were dodging significantly sized chunks of flywheel, crank and engine block.

Toyman01 (Moderately Supportive Dude) said:

In reply to Robbie (Forum Supporter) :

Some of the diesel pushers are well over 600 hp and 1400 lb-ft of torque. It probably wouldn't even slow down. 

They run up and down I 95 at 80 plus towing 25' enclosed trailers every spring and fall. 

This. The rocket surgeons that pilot these gigantic bus monstrosities probably never noticed. 

ShawnG said:

From all the folks who have been stuck behind RVs on holiday:

Also see- most resident floridians and the ones that have to deal with random rv bullE36 M3 daily, like me!

I used to want an rv. Driving my house wherever sounded like a great idea. I'm pretty sure I'm over that. 

The flywheel. 

Pete. (l33t FS) said:

Robbie (Forum Supporter) said:

I cant believe the RV was strong enough to pull it that fast. And theoretically wouldn't the engine likely have locked up after throwing a rod or whatever else?

I see the math but I call BS on actually achieving 50k crank RPM

When Miatas were new, there was a story going around about a tow company picking one up by the front wheels.  While it was in 1st gear.  Engine did not tolerate that.

A guy on the Miata subreddit just bought a really cheap NA6 Miata because a guy towed it behind an RV in 1st gear and turned the 1.6L into metal confetti.

I'm always fascinated by the amount of vehicles I see being towed behind RVs that I know come only with an automatic transmission. Unless they leave it running the entire time they are towing it.

In reply to NickD :

For a lot of vehicles, GM says you can flat tow just fine, but start the engine for a few minutes every few hours.

When I was at Saturn, we did a lot of towbar installations.  Saturns were popular as "toads" because they had electronic odometers that would not rack up miles, and the automatic transmissions were basically manual transmissions with servos and clutch packs instead of shift forks and sliders.  So they could be flat towed indefinitely.

More than once, someone would pick up their new Saturn by hitching it up to their RV and driving off.

In reply to NickD :

There are several automatic-equipped vehicles that can be flat towed. I know several years of Malibu can be as well as Ford's Fusion. The RV world produces a list every year.

Anything 4wd with a transfer case that can be placed in neutral is good to go. For instance, my 4wd Suburban can be. My 4wd Silverado can't. My go to dingy is the XJ and it's an auto.

In reply to Toyman01 (Moderately Supportive Dude) :

Just don't overshift to 4-Low. 

Pete. (l33t FS) said:

APEowner said:

I suspect the flywheel blew apart as they were coming up to speed.

Not before the engine came apart.  Once the flywheel exploded, the engine would have stopped turning.

 

I mean, the bottom end probably made like the Kool-Aid Man at around 9000-10,000, so the flywheel would have had to come apart even higher than that.

 

And the rods letting go USUALLY doesn't result in the crank snapping, so the now-imbalanced crank probably let go somewhere between the rods setting sail and the leftover rod chunks scything through the block, and the flywheel exploding.

 

Of all the times to not have a GoPro mounted under a vehicle!

After some sleep and looking at the video on a real monitor I would say that you are correct.  I now suspect that the whole back of the crank along with the rods, pistons and flywheel departed the vehicle in one distorted flailing assembly.  Whatever the sequence I bet it was spectacular and I agree that it's too bad there's no video.

APEowner said:

Pete. (l33t FS) said:

APEowner said:

I suspect the flywheel blew apart as they were coming up to speed.

Not before the engine came apart.  Once the flywheel exploded, the engine would have stopped turning.

 

I mean, the bottom end probably made like the Kool-Aid Man at around 9000-10,000, so the flywheel would have had to come apart even higher than that.

 

And the rods letting go USUALLY doesn't result in the crank snapping, so the now-imbalanced crank probably let go somewhere between the rods setting sail and the leftover rod chunks scything through the block, and the flywheel exploding.

 

Of all the times to not have a GoPro mounted under a vehicle!

After some sleep and looking at the video on a real monitor I would say that you are correct.  I now suspect that the whole back of the crank along with the rods, pistons and flywheel departed the vehicle in one distorted flailing assembly.  Whatever the sequence I bet it was spectacular and I agree that it's too bad there's no video.

Give it a few days.  Some youtuber with too much money and a screaming need to produce "content" will make a video of it.

Like Mythbusters, but stupid.

My guess?  Somewhere around 15 or 20,000rpm, the pistons turned to jello, which threw the balance way the hell off as the remains of the rods were sawing through the crankcase.  The crank then broke at the front, which allowed the main caps to break, which then threw a crank/clutch/flywheel assembly out the bottom of the vehicle.  It would be interesting to find the chunk.

I bet the entire disassembly process, from the first piston failure took, at most, a second.

In reply to KyAllroad (Jeremy) (Forum Supporter) :

It already exists.  There was some d-bag in the UK who would do stunts like this.  The one video I saw was of some UK-market jalopy (some forgettable Vauxhall sedan?) that he pulled the head off and towed down some back road.

I say d-bag, because the first thing that happened was the oil pump geysered all of the oil in the oil pan up through the block's deck, and all over the road.

In reply to Pete. (l33t FS) :

Link or it didn't happen 

In reply to P3PPY :

Not giving him the benefit of links.