"Motor racing is dangerous..."

[unclefester]

You sir are an opinionated pillock in my view.

If you bothered reading what I said you wouldn't make yourself look stupid by posting rubbish, but please carry on digging your own hole.

You jump to stupid conclusions without knowing anything about the circumstances, from the safety of your keyboard....

"Some bloke down the pub"....you really are simply an insulting bore.

Do you sometimes say something constructive on here?

Edited by unclefester on Sunday 18th June 18:48

[Mr2Mike]

unclefester said:

T
"Like a cannonball" is often used as metaphor...FFS!

The "like" suggests it is a simile

"at such a pace that it'd have been like being hit by a cannonball"

It would be much more like being hit by the remnants of a light alloy piston moving at a small fraction of the speed of a cannonball. It could quite probably have hurt someone, but I doubt it would have been quite equivalent to a cannonball converting someone into a red paste.

[unclefester]

Mr2Mike said:

The "like" suggests it is a simile

"at such a pace that it'd have been like being hit by a cannonball"

It would be much more like being hit by the remnants of a light alloy piston moving at a small fraction of the speed of a cannonball. It could quite probably have hurt someone, but I doubt it would have been quite equivalent to a cannonball converting someone into a red paste.

Yes, agreed... it is a simile but he was using a simile to speak metaphorically (rather than literally) about an admittedly light alloy piston...

I'm sure if he'd had any idea that assorted Sunday keyboard artistes would be picking over his phrasing forensically he would have said " something which I thought resembled a piston was flying through the air at an indeterminate speed and in the nanosecond I realised it was headed towards a marshall I became concerned for his safety."

But that's not what he said! ::::::::::::::::::::::

For sfaulds benefit, I didn't say the engine 'seized', I said it blew up. One rod welding itself then getting smashed as the crank continued to turn indicates the crank was turning, no?

Also I didn't suggest that it was 'speeding the internals up".

If you seriously want to debate, at least try to be accurate yourself.

We've all built race engines this end, and raced, so please don't be so bloody condescending.

Edited by unclefester on Sunday 18th June 20:02

[BertBert]

There's a different sum to do here. What if the big end seized at TDC. And for a flight of fancy, the piston is then travelling in a circle (ignoring the constraints of the cylinder/block. Then the gudgeon pin of the piston is 90 (guess) + 45=135mm from the centre of rotation.

What speed does an object have rotation around a centre, radius 135mm at 8000 rpm? I get to 227mph.

135mm=5"
Diameter=10"
Circumference=30"=2.5'
Ft/hour=8000*2.5*60=1.2M
Mph=1.2M/3/1760=227

Perhaps my maths is wrong!

Bert

[DCL]

The figures add up but the 'Conservation of Momentum' laws of physics would kick in and the rpm would drop (spinning dancer principle). If you want to accelerate an object you need to add energy from somewhere. Now you could argue that might come from the rest of the system (the other three cylinders and flywheel) but it takes a lot of energy to break open a block and sheer a rod, so I think we can safely say we are in negative energy territory.

Edited by DCL on Sunday 18th June 23:35

[unclefester]

Sweet weeping Jesus....OF COURSE there must have been some unusual forces or a concurrence of unlikely events involved here, which resulted in a highly unusual incident.

This is why I posted the subject, both my buddy and I realised it was a highly unusual blow-up.

I've had a broken rod open up a crankcase through 360°, we collected around 30 pieces of shrapnel from the track, and another which was all contained inside the bonnet, but never anything where a piston (assuming that's what it was) exited at 90° too its habitual path.

Saying that something 'can't happen', simply because you've not heard of it happening before is not science, it's dogmatic foolishness.

[dsl2]

Many years back my Caterham Hayabusa blew its (badly) modified oil filter off at Pembery during a sprint subsequently exploding itself at around 9500rpm, some kindly soul later sent me some pictures of the occurrence & in the smoke & steam plume you can clearly see a number of metal engine bits & pieces being ejected still with some considerable force having punched through the alloy side skin of the car, not enough to knock your block off I'm sure but looked like enough speed to ruin your day if you were close enough!

[unclefester]

dsl2 said:

Many years back my Caterham Hayabusa blew its (badly) modified oil filter off at Pembery during a sprint subsequently exploding itself at around 9500rpm, some kindly soul later sent me some pictures of the occurrence & in the smoke & steam plume you can clearly see a number of metal engine bits & pieces being ejected still with some considerable force having punched through the alloy side skin of the car, not enough to knock your block off I'm sure but looked like enough speed to ruin your day if you were close enough!

Thanks for that!

[DCL]

Just to keep the entertainment value going, lets look at a real life blow-up. A little more extreme than the engine in question, but the nature of the failure is much the same as has been proposed - a 360 degree section out of the block at high RPM

https://www.youtube.com/watch?v=v8b4fztU1Ek

Now if you were in close proximity to that, I'm sure it would leave a lasting impression, and your description may embellish it a bit. But there's no 'cannon' holes in the wall and all the departing parts are quite easily seen by the camera - their speed and velocities what you might expect.

Edited by DCL on Monday 19th June 10:36

[dsl2]

As DCL says if nothing else it certainly gets your attention when it lets go in a big way, the jolting through the car & racket made as it smashed itself to bits was enough to make me wince & shut my eyes until it was over then there is the added pain of having to stump up for a new motor to contend with too lol

[unclefester]

My 360° blow-up was on a bike and I copped a piece of crankcase in the knee.

No big damage to the knee but not something you forget in a hurry and I was lucky not to lose it on the oil.

[300bhp/ton]

unclefester said:

I just spoke with my buddy here again, it happened at Spa, he thinks probably 2007

Didn't your original unedited opening post say this happened recently?

unclefester said:

but as I said, the piston, assuming that is what it was, was never found

Really, maybe aliens 'beamed it up'?

Because....

unclefester said:

Checking later, it passed within 6' of a marshall

How can a relatively large metal object, not moving all that fast, at least not by the time it punched through an engine block and bodywork, and somehow missing the ground (or maybe bouncing off of it )

unclefester said:

had a very clear image of a piston exiting right, on a low trajectory

Then go completely unfound when there were marshals only 6' away?

And what does "checking later" mean in this context? Was there video evidence? Else there really is no way to check after the fact.

unclefester said:

I reported the incident exactly as it happened

Have you? Funny I didn't think you were there.

unclefester said:

as repeated to me yesterday by who was driving the car at the time.

So how do you know they didn't embellish the incident to begin with?

[unclefester]

When I was at his place on Saturday I was under the impression it was within the last couple of years.

When I rang and asked him various things about the incident that came out of this discussion, he told me where it was, and when.

I'm sure you're better qualified to quantify the probability of alien intervention than I am.....it's not something I'd considered I must admit....do you think they might have needed a Vauxhall piston for some reason?

Edited by unclefester on Monday 19th June 17:40

[justleanitupabit]

sfaulds said:

FFS - can someone please explain how an engine seizing (welding the rod to the crank) speeds up the internals?

Let's face it, a bloke down the pub told you a fairy tale, and you decided to post it on the internet. I suggest you learnt when to put down the spade and walk away from the hole.

Indeed.

A Caterham flavour urban legend.

[unclefester]

justleanitupabit said:

Indeed.

A Caterham flavour urban legend.

<< Sigh>>.

I don't know why you bother quoting the above, I didn't say any such thing.

People seem to post without having actually read the bloody thread!

Edited by unclefester on Tuesday 20th June 20:46

[amancalledrob]

unclefester said:

<< Sigh>>.

I don't know why you bother quoting the above, I didn't say any such thing.

People seem to post without having actually read the bloody thread!

Edited by unclefester on Tuesday 20th June 20:46

I've read the thread carefully and I still think you're wrong. Sorry about that

[Risky]

My brother in laws 1300 cross flow in his stock car blew up spectacularly. I saw the piston leave the block. It did injure a marshal when the silly sod picked it up. It was still very hot.
Whilst it did look very spectacular it had lost most of its momentum when is passed through the block.

[Risky]

My brother in laws 1300 cross flow in his stock car blew up spectacularly. I saw the piston leave the block. It did injure a marshal when the silly sod picked it up. It was still very hot.
Whilst it did look very spectacular it had lost most of its momentum when is passed through the block.

[unclefester]

amancalledrob said:

I've read the thread carefully and I still think you're wrong. Sorry about that

OK, show me where I stated it had "seized" and where I stated that by seizing, or in any other way," the internals had speeded up"?

I'm "wrong" in what sense?

[amancalledrob]

unclefester said:

OK, show me where I stated it had "seized" and where I stated that by seizing, or in any other way," the internals had speeded up"?

I'm "wrong" in what sense?

I don't believe for a moment that a piston can exit a block, punch through the bodywork of a car, and still be travelling fast enough to hurt someone. I'm basing this on the fact that maximum piston speeds under normal circumstances are usually no more that around 24m/s. I can't imagine a failure mode that could allow the crank to accelerate the piston to a greater speed and then fling it completely free of the car.

Please note that this doesn't mean you're actually wrong, it just means I think you are. New facts could still change my mind, I just can't imagine what they'd be.