Why does this happen?

[to4garret]

watch this video first,

http://www.1320video.com/RedRumTrannyDrop.php



cliffs,

goes for drive, snaps flywheel bolts...

3rd gear would only be 120-130kph as well, not mph, mericans ^_^

 

[brisvr4]

Used a rattle-gun to do up the flywheel bolts and they backed out on him.
How fast is 8500rpm in 3rd?

 

[DOUGMO]

have they done anything up at all?

 

[to4garret]

8500 would be close to 150kph in 3rd i think.

if you look at the part when they show the flywheel/clutch on the ground, it looks like the flywheel bolts are still there, like they have sheared from the crank.

 

[JayRome]

8500 would be close to 150kph in 3rd i think.

if you look at the part when they show the flywheel/clutch on the ground, it looks like the flywheel bolts are still there, like they have sheared from the crank.

yer was thinking that too.... not dangerous at all having the flywheel spinning at 8500rpm attached to nothing......

 

[TMAK]

hahaha that is GOLD!!!
scary as and funny as!

 

[DOUGMO]

i was waiting for the flywheel to come through the bonnet

pretty disapointed to be honest

 

[EVO-00X]

Notice in the video he was bouncing off the rev limiter for a couple seconds just before you hear the noise? this meant that there was no load at all on the engine through the drivetrain and the clutch wasnt working for him to change up a gear.

I reckon the crank would have snapped off at number 4 journal (its not uncommon for our 4G cranks to crack there, even Rob Barac has had a crank crack in number 4 and Steve has had crank failure in the same spot too).

The flywheel in turn changed angle and because it was spinning at high rpm snapped the flywheel bolts crashing into the bellhousing breaking the bellhousing off.

 

[JiMi]

nasty... be intersting to see what other damage happened.. would have been interesting in the box went thru under the car

 

[to4garret]

Notice in the video he was bouncing off the rev limiter for a couple seconds just before you hear the noise? this meant that there was no load at all on the engine through the drivetrain and the clutch wasnt working for him to change up a gear.

I reckon the crank would have snapped off at number 4 journal (its not uncommon for our 4G cranks to crack there, even Rob Barac has had a crank crack in number 4 and Steve has had crank failure in the same spot too).

The flywheel in turn changed angle and because it was spinning at high rpm snapped the flywheel bolts crashing into the bellhousing breaking the bellhousing off.

this is exactly what i was fishing for,


its a plausible explanation. gearbox is still attached to the chassis of the car, hence why it didnt go under/through.

its also unusual for a flywheel to "fly off" and also just as uncommon for flywheel bolts to shear.

however, is there any particular reason number four (crank or bigend btw) crack that you know of?

 

[EVO-00X]

A possible two-fold explanation caused by fatigue from:
1. Its the one taking most of the abuse from the clutch/flywheel side of the crank; and
2. Its the one furthest away from the balancer pulley at the front of the engine

Both Rob's and Steve's cracked in the same place:

Rob Barac: "...make sure you get it crack tested before you do anything, they are prone to crack in the undercut radius on the 4th journal, if it isnt already cracked, then its happy days. Make sure you get it crack tested, they can still be cracked from factory, I have seen it before. We micro polished all of the counter weights, then nitrited the crank, after 2 years of racing it it finaly cracked so I put in a completly standard one (after getting it nitrited) and ran it another 2 years. It cracked in the same spot too, so I ended up buying an eagle crank (still a 2 litre) and ran it for another 3 years... in early 06 I went the 2.4 with the eagle bottom end and have been running it since..."

 

[EVOCPE]

So get 1 of these

So this doesnt happen

 

[DOUGMO]

bazeng has one similar to that

 

[bazeng]

Dougmo, good eyes mate, it actually is one of those but polished (BLING!!!)

 

[GSRSOL]

So get 1 of these

So this doesnt happen

ouch!!! :unsure::unsure:

 

[evopwr]

damn that would be scary shit!!!

 

[DOUGMO]

ouch!!! :unsure::unsure:

thats the theory, or it makes a much bigger hole in the bonnet the size of a scatter sheild!

 

[bazeng]

I prefer to have my gearbox smash to bits rather than the motor / intercooler setup..

You can get a 360 degree scatter shield.. keep in mind that they are a heavy item..

 

[steve]

I've been looking around for a scatter-shield lately - are they available in australia to suit lancers?

 

[bazeng]

The guy who makes them is a GVR4 guy in the US.

They should fit the Lancers providing the bellhousing on a VR4 is the same..