NormanS
Well-Known Member
But don't you see that that is nonsense?
Look at Chalwin Valve, as instanced in my previous response.
URGENT ! HOW TO STOP A DIESEL ENGINE ?!
- Thread starter Babylon
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Look at Chalwin Valve, as instanced in my previous response.
Stemar
Well-Known Member
I think Elessar is referring to the safety aspects. It's one thing to put something (Not your hand!) over the intake to stop a small engine when the stop solenoid doesn't want to play, but you're going to need something pretty substantial to starve a 50HP engine that's decided to eat its own oil and is revving out of control. I hate to think of the vacuum that could produce.
I get the CO2 extinguisher idea, IF you have a single inlet at the air filter, but how big an extinguisher would you need to stop one that has several holes in the filter housing like mine, in a big engine bay? TBH, I don't know how I'd stop my engines if that happened. I know one thing, I'm not going to be lying across the engine groping for the manual stop! I rather think I'm going to be getting the grab bag and putting the dinghy over the side to watch from a safe distance until things calm down and I can see how big a hole the flying con rod made in the side of the boat. It isn't practicable on Jazzcat, but I reckon the ideal arrangement would be a built-in CO2 system for the engine bay, with the volume to flood it with gas and keep it flooded for a few minutes. I'd guess that would be a fair sized system, so something an average boat owner would have to think seriously about - CO2 system or liferaft, for example.
I get the CO2 extinguisher idea, IF you have a single inlet at the air filter, but how big an extinguisher would you need to stop one that has several holes in the filter housing like mine, in a big engine bay? TBH, I don't know how I'd stop my engines if that happened. I know one thing, I'm not going to be lying across the engine groping for the manual stop! I rather think I'm going to be getting the grab bag and putting the dinghy over the side to watch from a safe distance until things calm down and I can see how big a hole the flying con rod made in the side of the boat. It isn't practicable on Jazzcat, but I reckon the ideal arrangement would be a built-in CO2 system for the engine bay, with the volume to flood it with gas and keep it flooded for a few minutes. I'd guess that would be a fair sized system, so something an average boat owner would have to think seriously about - CO2 system or liferaft, for example.
jamie N
Well-Known Member
KompetentKrew
Well-Known Member
I can 't use one of those because, as I've already told you, my boat doesn't have one of them fitted.
It was quite obvious that @Elessar was referring to the 99% of leisure boats like mine.
DanTribe
Well-Known Member
I've told this tale before.
An uncle worked as an engineer on submarines, he kept a tin tea tray in pride of place on display. He claimed that it saved the ship when an engine ran away and he slapped it over the air intake. It was very dented.
Not sure if it was true but it made a good story.
An uncle worked as an engineer on submarines, he kept a tin tea tray in pride of place on display. He claimed that it saved the ship when an engine ran away and he slapped it over the air intake. It was very dented.
Not sure if it was true but it made a good story.
AntarcticPilot
Well-Known Member
Just to put some figures on the air intake issue, I did the following calculation. On every second revolution, my Volvo 2003 (a mere 28 hp) takes in 1.3 litres of air. At 2000 rpm, that's 1.3 cubic METRES of air per minute. While I'm sure that a solid plug in the air intake would stop it, I think it would stand a good chance of wrecking anything less robust - such as a hand. However, as others have noted, the air filter itself would stop anything being drawn through the filter to the engine, so a cushion would probably work - but wouldn't be the same afterwards!
Boater Sam
Well-Known Member
I have seen all the paper off a blocked air filter sucked into a BMC 1.5D engine.......to it's detriment.
Elessar
Well-Known Member
Mine needs 34,000 litres of air per minute. That’s 1,200 cubic feet. It sucks in stuff quite quickly.
Elessar
Well-Known Member
When the Diesel engine is running away you need to look for a solution and look for it fast.
If you have a chalwin valve, great. I’ve never heard of one but I’m sure Jacob-Rees Mogg would have the sort of boat that would have one.
For those in the current century quick thinking is required.
For that think CO2 not blocking the intake.
penberth3
Well-Known Member
CO2 is an interesting idea. Have you ever tried it?
Elessar
Well-Known Member
Sort of. stopped an engine at planing speed due to accidental gas discharge. Engine continues to pump the diesel in and it comes out of the exhaust. Absolute stink of diesel and a stopped engine. And I was very very confused. I thought the engine had destroyed itself until I realised what had happened.
Col, Volvo engineer of this forum, recommends the CO2 solution in more static situations and has drummed it into me. “Don’t try and block the intake”
penberth3
Well-Known Member
Thanks, so that was an auto discharge. I'd worry about gassing myself trying to do the same thing with a hand held extinguisher in a small space. Plus the risk of flying metal if you're too late!
Elessar
Well-Known Member
Well your “better off to run” argument is valid but we weren’t comparing CO2 with running we were comparing it with trying to choke the engine. Which I maintain is a poor choice.
