"run away"

[Pappa Lazarou]

When I posted this thread I thought it was ended with the very first reply fom Nigel who simply said, cover the air intake, but to see how it as turned out now, to be a really enthralling subject.

 

 

If this were to happen in a marina, or travelling out on the canal, it would be to someone new to boating (or even an experienced boater)very frightening. The consequences to people,and boats around could be very grave, but if this was to happen whilst cruising down the river, what then?.

 

 

I hope threads like this do not deter people from joining the boating fraternity, and I am sure that incidents like this which can occur,are very seldom.

At least we have some insight has what to do if it ever happens to us, ruuuuuuuuuuun!

[Morat]

The air intake route is the best - but not infallible.

The old shape (round cab) 4 ton Leyland army lorries were notorious for running away, but they would do it with the engine spinning in reverse which meant that the intake was now the exhaust pipe...

So I don't know if Listers/Bolinders etc are capable of doing this (I assume it requires some quirk in the valve gear) but you might want to check which pipe is sucking air before you block it!

[nb Innisfree]

Isn't that an impossibility?

 

Tim

 

Not if the extiguisher was inverted.

[bizzard]

The air intake route is the best - but not infallible.

The old shape (round cab) 4 ton Leyland army lorries were notorious for running away, but they would do it with the engine spinning in reverse which meant that the intake was now the exhaust pipe...

So I don't know if Listers/Bolinders etc are capable of doing this (I assume it requires some quirk in the valve gear) but you might want to check which pipe is sucking air before you block it!

Years ago when i was an apprentice mechanic i was starting up and old Bedford truck with a Perkins P6 that started up backwards, exhaust gushing out of the air intake and sucking in air at the exhaust which put the engine stop out of commision. After selecting first gear to drive it forward to stall it against a wall and it went backwards i had to select reverse to drive it forward, all quite frightening.

[Teadaemon]

Not if the extiguisher was inverted.

 

How would inverting the extinguisher alter physics in such a way that carbon dioxide forms a liquid phase rather than subliming?

[ditchcrawler]

Provided it wasn't liquid CO2, none whatsoever.

I have filled large engines BCF more than once and I can confirm they do stop undamaged even with the governor wide open.

[carlt]

How would inverting the extinguisher alter physics in such a way that carbon dioxide forms a liquid phase rather than subliming?

If the pressure in the extinguisher is high enough then the CO2 would be in a liquid state (5 atmospheres, iirc).

 

I would say that I have no idea what pressure CO2 extinguishers are filled to but would imagine that they would be effective a long time before a liquid state is achieved.

[nb Innisfree]

If the pressure in the extinguisher is high enough then the CO2 would be in a liquid state (5 atmospheres, iirc).

 

I would say that I have no idea what pressure CO2 extinguishers are filled to but would imagine that they would be effective a long time before a liquid state is achieved.

 

Stored in the region of 200 bars so it is in liquid form, much like LPG but higher pressure of course.

[Timleech]

Stored in the region of 200 bars so it is in liquid form, much like LPG but higher pressure of course.

 

Test pressure (on mine, anyway) is 200 bar, so I expect 'working' pressure to be half that or less.

 

Tim

[mango]

I used to use liquid carbon dioxide as a coolant for lab equipment in the 70s. We bought it from the Distillers Company. The cylinders with a dip tube to discharge liquid carbon dioxide had a white stripe down the side.

[lynalldisocvery]

Interesting topic.

 

I actually had the start of a runaway on the car last weekend (Freelander).

 

Blown oil seal on the turbo, so self feeding on engine oil.

 

Fortunately, I spotted it accelerating away before it red lined, and managed to stall it, because the ducted air intake on a freelander would be a pig to block or to get CO2 into.

 

Anybody want to buy a 2002 Freelander with knackered turbo?

 

 

What, thats all thats wrong with it

 

 

Lynall

[Guest]

What, thats all thats wrong with it

 

 

Lynall

 

Actually diesel Freelanders are not that bad, that is when compared to a K series petrol which is where it gained it's well deserved reputation for unreliability.

[Guest]

i may have dreamt this, but am near certain that I read about a giant diesel engine that had CO2 plumbed into the air intake for this very reason.

[boingy]

I think many of the "block the air intake" folk are not taking into account how utterly terrifying a runaway diesel engine can be. By the time you notice it the revs will already be way in excess of comfortable and there will a huge amount of smoke and one heck of a lot of noise. I'd have to climb down into the engine bay to get near the air intake and the fuel cutoff on our engine. No way, Jose.

 

Frankly, unless you are very brave and very sure of yourself the best advice would be to get clear and let the engine gods decide its fate imho.

[nb Innisfree]

I think many of the "block the air intake" folk are not taking into account how utterly terrifying a runaway diesel engine can be. By the time you notice it the revs will already be way in excess of comfortable and there will a huge amount of smoke and one heck of a lot of noise. I'd have to climb down into the engine bay to get near the air intake and the fuel cutoff on our engine. No way, Jose.

 

Frankly, unless you are very brave and very sure of yourself the best advice would be to get clear and let the engine gods decide its fate imho.

 

If you do make sure you're wearing a cricket box. Or whatever the're called.

[ditch paddler]

Sorry to contradict, by in my case, caused by excess sump oil, a rag up the air intake did stop it in seconds.

My neighbours 1.5 BMC run away on its oil i and another neighbour went to help, i as many of you describe removed the air fitler and bunged the manifold with rag, it slowed the engine slightly but kept running my other neighbour removed his fleece and blocked the exhaust with it, the engine stopped instantly. I guess we have all had are own experiences.

 

No, you need to stop ait getting in, so you block the air intake.

(This has been said several times already!!)

If you tried to block the exhaust all it does is "explode" the weakest point along it.

 

Deltic's were fitted with CO2 bottles, I believe.

mmmm Interesting but i cant see your theory of exploding the weakest point!

[Graham Davis]

My neighbours 1.5 BMC run away on its oil i and another neighbour went to help, i as many of you describe removed the air fitler and bunged the manifold with rag, it slowed the engine slightly but kept running my other neighbour removed his fleece and blocked the exhaust with it, the engine stopped instantly. I guess we have all had are own experiences.

 

 

mmmm Interesting but i cant see your theory of exploding the weakest point!

 

Because as the pressure builds up it will find the weakest point to try and escape, and that could be the exhaust pipe, typically at a joint or even the manifold.

 

And in your case above you did both, so how do you know which actually stopped the engine?

[GSer]

I've had two engines run away on me, one was spectacular, a supercharged nitro-metanol burning triumph rail went off when i was riding it, it wrote off the bike, only the wheels and forks survived, the second time was when Apache had the cracked head( before i knew about it) dropping down through a lock the boat hooked up on some fallen brickwork, the serious angle the boat was listing at, caused the engine to self fuel, the lock filled with smoke in very little time and the engine was accellerating quickly, i had the centre line close so i gave it the big heave-ho and the boat righted itsself and the engine returned to its normal thunk ker thunk rhythm. Phew!

 

When i checked over apache the oil level was half an inch over due to water in the sump.

[steve hayes]

Engine test cells where new engines are run are normally fitted with CO2 feeds into the inlet in case of a run away, you never know if a seal has been missed out on assembly.

 

An exhaust will often blow apart at a rusty joint if you block the outlet, memories of student cars flooding back

[DandV]

We had a case of a truck engine running away at a service station. At the time the station was receiving a load of motorsprit. The truck had stopped to refuel and either before stopping the engine or immediately after restarting the engine ran away. The cause, the trucks engine had a snorkel air intake immediately down wind of the motorspirit storage tanks which were venting the displaced volume of the delivery in progress.

To decommission LPG storage vessels and lorries we used a diesel powered vapour compressor to empty the tank into a road vehicle. The emergency stop on the diesel compressor was fuel shutoff plus discharge of a fire extinguisher plumbed into the air intake system. fortunately never had to use it in anger but it was tested every time the extinguisher was due for a test or replace.

 

Don

[nb Innisfree]

An exhaust will often blow apart at a rusty joint if you block the outlet, memories of student cars flooding back

 

Yes quite likely If you think about it, after all a diesel engine is basically an air compressor capable of 20+bar of pressure.

[blackrose]

Interesting topic.

 

I actually had the start of a runaway on the car last weekend (Freelander).

 

Blown oil seal on the turbo, so self feeding on engine oil.

 

Friend of mine had the same thing happen with his new Vetus Deutz 185hp on a Dutch barge while he was travelling up the tidal Thames from Limehouse. He went down into the screaming engine room and managed to stop it but he said that the noise was horrendous. Fortunately the engine damage was fairly minimal. The next time he was out on the tideway he had a fire in the engine room when his inverter blew up! The guy had no luck on that boat.

 

By the way, does runaway engine only happen on old or turbocharged engines? Does it ever happen with modern non-turbo engines?

Edited October 17, 2012 by blackrose

[benfordboy]

I experienced a runaway on Dads BMC 1.5 a couple of years ago - still unsure what caused it (Although we found the sump overfull with diesely oil afterwards so that may have helped (Lift pump filter blockage) ) Damn scary at the time - Turned ignition off & fuel tap but it carried on revving like a race car !

 

Throwing my coat over the air filter & holding it over stopped it luckily ! - by this time Dad was making a exit onto the towpath !!

[mayalld]

What, thats all thats wrong with it

 

So far as the engine goes, yes (although I think the injectors are now fouled).

 

Its biggest problem is my complete lack of attention to keeping it clean and tidy!

[Guest]

Before his trial by media, I often wonder if this geezers engine had run away.

 

http://news.bbc.co.uk/1/hi/uk/368677.stm