"Motor racing is dangerous..."
Discussion
A friend I was visiting to collect some blanks he'd had cut for the DVA lift at TDC dial gauge supports told me today about a blow-up on track here not so long ago.
We'd been discussing dry sump pumps as I have a problem with the DS system on my Caterham....oil temperatures seem to be surprisingly low.
This guy has built and raced a 260bhp Caterham over the last 28 years and is a very well-known authority on Caterham competition and engineering.
Note...NOT some clot I bumped into "down the pub".
He has had problems with the pumps and warned me to check clearances on mine periodically.
He was racing at Spa, he was at high revs, when without any warning the motor grenaded.
Big 'bang' and he saw shrapnel, oil cloud and general mayhem, but had a very clear image of a piston exiting right, on a low trajectory, about level with the marshalling post!
Checking later, it passed within 6' of a marshall, and at such a pace that it'd have been [metaphorically speaking] ' like being hit by a cannonball. [/metaphorically speaking]..would very likely have been fatal, he reckoned, had it hit someone in the head.
It went through the crankcase and had no problem whipping through the alu skin of the Caterham!
We'd been discussing dry sump pumps as I have a problem with the DS system on my Caterham....oil temperatures seem to be surprisingly low.
This guy has built and raced a 260bhp Caterham over the last 28 years and is a very well-known authority on Caterham competition and engineering.
Note...NOT some clot I bumped into "down the pub".
He has had problems with the pumps and warned me to check clearances on mine periodically.
He was racing at Spa, he was at high revs, when without any warning the motor grenaded.
Big 'bang' and he saw shrapnel, oil cloud and general mayhem, but had a very clear image of a piston exiting right, on a low trajectory, about level with the marshalling post!
Checking later, it passed within 6' of a marshall, and at such a pace that it'd have been [metaphorically speaking] ' like being hit by a cannonball. [/metaphorically speaking]..would very likely have been fatal, he reckoned, had it hit someone in the head.
It went through the crankcase and had no problem whipping through the alu skin of the Caterham!
Edited by unclefester on Sunday 18th June 19:24
300bhp/ton said:
sfaulds said:
"Posting BS on the internet is dangerous..."
I'm not sure what prompted this thread, but it needs a bit of a maths reality check.
It was a Caterham, so reasonably safe to assume a 4 cylinder something between 1.3 and 2.3l in size.
Stroke would probably be no more than 90mm.
Max RPM around 8000
So, max piston speed would be about 24 m\s (53.6 mph). That's before its somehow had it's natural path altered by nearly 90 degrees, passed through (at very least) several mm of steel and ali in the block, 1mm of ali sheet (although if it went through the sideskin I'm not sure how it ever got as far as the edge of the track) and several feet of air (pistons aren't very aerodynamic).
Not exactly a cannonball....
+1I'm not sure what prompted this thread, but it needs a bit of a maths reality check.
It was a Caterham, so reasonably safe to assume a 4 cylinder something between 1.3 and 2.3l in size.
Stroke would probably be no more than 90mm.
Max RPM around 8000
So, max piston speed would be about 24 m\s (53.6 mph). That's before its somehow had it's natural path altered by nearly 90 degrees, passed through (at very least) several mm of steel and ali in the block, 1mm of ali sheet (although if it went through the sideskin I'm not sure how it ever got as far as the edge of the track) and several feet of air (pistons aren't very aerodynamic).
Not exactly a cannonball....
The ops post seems to be a work of fiction and/or massive over inflation of the facts I would think. Certainly don't recall seeing any mention in the MSA News or Scrutineering Bulletin on any such incident.
t' and fictional/massive inflation of the facts, based on zero actual knowledge of the incident, as admitted, nor first hand experience.One might say "Petty viciousness caused by alchohol or hangover"
Tough, you are wrong, I reported the incident exactly as it happened, as repeated to me yesterday by the engineer and designer who was driving the car at the time.
I have no axe to grind, but I don't like being accused of lying....so before you jump to ignorant conclusions, try thinking a little about how a calculation based on nothing but piston speed might perhaps be wildly out...
You have doubtless heard of 'slingshot effect' as used by NASA?
Consider....the blowup was found to have been caused by the Titan DS pump having suddenly lost the plot, which caused a big end to weld itself to the crank journal.
The crank was turning at over 8k....
I'm sure the posters of the above two comments would enjoy standing facing a piston trailing part of a conrod fired at their heads at a speed to be determined by the forces of physics...who knows what speed it was doing, my friend said it "would be like being hit by a cannonball..."
He didn't specify its actual speed, as he had no way of knowing it.... OK?
Edited by unclefester on Sunday 18th June 17:14
Thanks, I'm aware of ballistics speeds, plus a cannonball is rather heavier than a piston!
I was quoting the driver's own words. I've just spoken with him on the phone, he will send pix taken showing the damage.
I discovered something I didn't know, the Swindon tuned VX engine does indeed have a cast iron block, not alloy, and he further stated that he was right on the edge of the track by the marshaling post, so whatever it was that punched a hole in the side skin didn't have far to go before contacting something, human or otherwise.
The piston was not found, so it clearly flew some considerable way.
No trace of the missing piston was ever found inside the engine...
The point he was making was that a random event, not caused by pilot error, could have injured a marshal
"Like a cannonball" is often used as metaphor...FFS!
I was quoting the driver's own words. I've just spoken with him on the phone, he will send pix taken showing the damage.
I discovered something I didn't know, the Swindon tuned VX engine does indeed have a cast iron block, not alloy, and he further stated that he was right on the edge of the track by the marshaling post, so whatever it was that punched a hole in the side skin didn't have far to go before contacting something, human or otherwise.
The piston was not found, so it clearly flew some considerable way.
No trace of the missing piston was ever found inside the engine...
The point he was making was that a random event, not caused by pilot error, could have injured a marshal
"Like a cannonball" is often used as metaphor...FFS!
Edited by unclefester on Sunday 18th June 17:16
Slingshot effect as used by Nasa means the use of the gravity-well to accelerate the object entering it at a tangent, so it leaves faster than it enters.
Discus throwers use this simple centrifugal method as it means the discus goes further, faster, than they could throw it otherwise...
It's basically centrifugal force as in a spinning engine.
In this case the engine was rated to hard cut at 8250rpm.
I haven't seen the photos, so it's hard to see how a piston could have been exiting under centrifugal assistance unless the case had somehow been opened through through 360° and done one or more revolutions with the big end welded to the crank....all I can say is my post is a 100% accurate report of what I was told, and the person concerned is highly respected and not known for inventing stories...
Possibly the rod snapped, then the spinning crank somehow batted the dropped piston/parts out the side next time it came around.
Discus throwers use this simple centrifugal method as it means the discus goes further, faster, than they could throw it otherwise...
It's basically centrifugal force as in a spinning engine.
In this case the engine was rated to hard cut at 8250rpm.
I haven't seen the photos, so it's hard to see how a piston could have been exiting under centrifugal assistance unless the case had somehow been opened through through 360° and done one or more revolutions with the big end welded to the crank....all I can say is my post is a 100% accurate report of what I was told, and the person concerned is highly respected and not known for inventing stories...
Possibly the rod snapped, then the spinning crank somehow batted the dropped piston/parts out the side next time it came around.
Edited by unclefester on Sunday 18th June 17:18
downsman said:
I am not an expert, but it seems to me that the forces acting on an aluminium piston that are great enough to break the steel conrod connecting it to the crank must be orders of magnitude higher than those it was designed to withstand.
I am happy to accept the description given without question, and look forward to seeing the photos. Shame the internet makes people so cynical
Thanks, I am inclined to agree! I am happy to accept the description given without question, and look forward to seeing the photos. Shame the internet makes people so cynical
Doncha just love keyboard warriors....
I can only assume that the effect was due to the rotational speed and inertia of the crank, otherwise I admit the whole thing sounds unlikely.
The unfortunate driver hasn't yet located the pix, and wants no obvious identifying company stickers visible....whether he trusts my PS skills (or whether he can find them) is another thing entirely.
DCL said:
I think the reason for the cynical response is more to do with the fact that those with experience in these matters know better. Stuart, in particular, has a great deal of racing engine experience and probably a few un-contained failures too.
The truth is that pistons accelerate to from 0mph to 50mph, and back to 0mph in the space of 100 mm or so, and are subject to considerable acceleration forces. BUT they do not go that fast, and are often moving slower than the car itself. Perhaps the piston got thrown from the car, but in terms of the OP description, the story just doesn't add up to the engineering geeks I'm afraid.
They may think they "know better" but here's a chance for them to learn something new.The truth is that pistons accelerate to from 0mph to 50mph, and back to 0mph in the space of 100 mm or so, and are subject to considerable acceleration forces. BUT they do not go that fast, and are often moving slower than the car itself. Perhaps the piston got thrown from the car, but in terms of the OP description, the story just doesn't add up to the engineering geeks I'm afraid.
Has anyone here actually tried firing an alu forged piston through whatever wall thickness of cast iron is in a VX block, and then through the alu skin of a Caterham? Measuring speed and trajectory?
With the conrod stub welded to the journal?
Calculated the effect of a crank journal smacking a piston lodged in the crankcase, while turning at 8000 rpm?
I very much doubt it.
I also think the very well known driver(engineer) of this car, who has been racing for 30 years or so, would tend to be believed if he was explaining what happened, which he himself thought was pretty odd, but I was the person he told about it.
if people on here, whatever their engineering background, choose to disbelieve what I've posted due to preconceived ideas and received wisdom, and without knowing anything about me as a source, that's up to them.
Science, in the form of the French Academie des Sciences, claimed that people who had direct experience of meteorites falling to earth loftily stated "These people are mistaken, lying or fabulating.
It is clearly impossible for stones to fall from the skies, as there are no stones in the sky."
Yeah, right!
Edited by unclefester on Sunday 18th June 17:24
Hard to see that one being reusable!
I just spoke with my buddy here again, it happened at Spa, he thinks probably 2007, he was very close to the Marshall post, but as I said, the piston, assuming that is what it was, was never found, but was certainly not inside the car or the remains of the engine.
I don't see any point in bandying estimated velocity calcs around on here, I'm merely reporting the facts as presented.
Stones do indeed fall from the sky....
I just spoke with my buddy here again, it happened at Spa, he thinks probably 2007, he was very close to the Marshall post, but as I said, the piston, assuming that is what it was, was never found, but was certainly not inside the car or the remains of the engine.
I don't see any point in bandying estimated velocity calcs around on here, I'm merely reporting the facts as presented.
Stones do indeed fall from the sky....
Edited by unclefester on Sunday 18th June 17:26
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?
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 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..."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.
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
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.
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 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! 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?
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
BertBert said:
OT now, but I think we've got bored with taking the p out of UF for his daft urban legend motorsport story, so...
I find that going to school in the 70's I've ended up being very confused about units, imperial and metric. I'm happy in inches and cm at the same time, yds/m, lb/kg/g, litres/gallons (UK and US). But I'm not very good with speed in m/s. I can't really visualise what 4m/s is.
Hey ho!
Bert
<<Yawn>>I find that going to school in the 70's I've ended up being very confused about units, imperial and metric. I'm happy in inches and cm at the same time, yds/m, lb/kg/g, litres/gallons (UK and US). But I'm not very good with speed in m/s. I can't really visualise what 4m/s is.
Hey ho!
Bert
Pillock! People have posted in response showing that "it's quite possible" and the maths shows it is as well.
Even without that, you are being fantastically arrogant if you think your personal opinion shows an actual event to be "impossible" because in your limited experience you've never seen it.
Ignorant, arrogant, and just plain silly.
I'm completely bored with such stupid responses myself.
Fortunately some people seem to have taken my post as it was intended.
Edited by unclefester on Friday 23 June 18:55
'Insulting people'???
Seems to me several people on here have been throwing insults in my direction.... accusations of bullst, lies, fiction, exaggeration etc, 'proved' by several shallow theories about 'piston speed' etc which show a tendency to jump to an easy conclusion and a willingness to rubbish people who the poster has never met, rather than imagine for one moment that perhaps he isn't actually the world authority on engine blowups that he would like to imagine he is.
Oh and the 'science degree' comment slayed me. What exactly do you know about the science background of either me, or the person who's engine blew?
Opining, as if you are speaking an obvious, demonstrable truth, when in fact you are simply stating a personal belief, is a bad move on the internet.
Several people who responded have said similar 'piston passing through block' incidents have been seen, so it seems to me that the repetitive, juvenile attempts to turn this into a 'taking the piss thread' say more about the mental age of the posters, than the accuracy of my friend's memory of his blowup.
The standard of 'debate' from several of the posters gives the impression of an average age of around 13.
It seems wisdom, or even common sense, on PH is in inverse proportion to post-count.
Get a life? Who has the bigger post count? Who spends more time on the keyboard?
Don't let me keep you from posting more repetitive nonsense though....
Seems to me several people on here have been throwing insults in my direction.... accusations of bulls
t, lies, fiction, exaggeration etc, 'proved' by several shallow theories about 'piston speed' etc which show a tendency to jump to an easy conclusion and a willingness to rubbish people who the poster has never met, rather than imagine for one moment that perhaps he isn't actually the world authority on engine blowups that he would like to imagine he is.Oh and the 'science degree' comment slayed me. What exactly do you know about the science background of either me, or the person who's engine blew?
Opining, as if you are speaking an obvious, demonstrable truth, when in fact you are simply stating a personal belief, is a bad move on the internet.
Several people who responded have said similar 'piston passing through block' incidents have been seen, so it seems to me that the repetitive, juvenile attempts to turn this into a 'taking the piss thread' say more about the mental age of the posters, than the accuracy of my friend's memory of his blowup.
The standard of 'debate' from several of the posters gives the impression of an average age of around 13.
It seems wisdom, or even common sense, on PH is in inverse proportion to post-count.
Get a life? Who has the bigger post count? Who spends more time on the keyboard?
Don't let me keep you from posting more repetitive nonsense though....
DCL, I fully understand your trying to make the peace, and calling for respect of seasoned petrolheads.....I'm one myself.
I was very well known on the 'Old Blatchat' where I apparently posted 'the funniest post', but I packed it in after the site was 'upgraded' (allegedly).
I also stopped my subs, so can't post there now, but for me the fun went out of the site years ago....and I, and a lot of others, stopped posting.
A great shame, it was a lot of fun 10 years ago.
I've posted thousands of times on Seloc. Just not much here.
I respect people based on their actions, not on postcount, and certainly not when they deliberately insult me.
I started the thread because I thought it was mildly interesting, and was jumped on, and accused of all manner of things from BS, exaggeration, deliberate retailing of untruths, fantasy, to 'being unscientific'.
Normally this sort of ad hominem attack is the defense of people who actually have no argument, or evidence for their position, and it's an admission of failure in debate.
As for Caterhams, I've had many, and competed in several of them, for the last 11 years.
The 'original source' who related this incident first hand is one of the most well-known people in the Caterham world.
But I protect my sources...
I was very well known on the 'Old Blatchat' where I apparently posted 'the funniest post', but I packed it in after the site was 'upgraded' (allegedly).
I also stopped my subs, so can't post there now, but for me the fun went out of the site years ago....and I, and a lot of others, stopped posting.
A great shame, it was a lot of fun 10 years ago.
I've posted thousands of times on Seloc. Just not much here.
I respect people based on their actions, not on postcount, and certainly not when they deliberately insult me.
I started the thread because I thought it was mildly interesting, and was jumped on, and accused of all manner of things from BS, exaggeration, deliberate retailing of untruths, fantasy, to 'being unscientific'.
Normally this sort of ad hominem attack is the defense of people who actually have no argument, or evidence for their position, and it's an admission of failure in debate.
As for Caterhams, I've had many, and competed in several of them, for the last 11 years.
The 'original source' who related this incident first hand is one of the most well-known people in the Caterham world.
But I protect my sources...
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