no kill cords on diesels?

zip · 04 June 2015, 03:35

Every boat I have owned has had a kill cord, which I always wear.

Any idea why there isn't one on a diesel?

John Kennett · 04 June 2015, 05:15

I don't know. Every diesel RIB that I've driven has had a kill cord!

Bigtalljv · 04 June 2015, 05:17

An ex-military diesel I assume Zip?

zip · 04 June 2015, 11:24

Jason,

Yep.

Poly · 04 June 2015, 11:57

Zip, Engineering wise adding a kill cord to a diesel is somewhat harder than a petrol (where you can short the ignition). There are also potential downsides to stopping diesels at high speed, instantly - you may not want to encourage "squaddies" to use the emergency stop unnecessarily. Different story if its your own boat though.

ncp · 04 June 2015, 13:23

What Poly said. And, the US Navy ordered them that way (I'm sure there is a study to back it up just like lifeguards not using kill cords on their IRB's)

You can add one to a mechanical diesel engine. For a mechanical Cummins, it's about $400. You would need to order a custom 24v solenoid. clloyd did it for his Willard.

two stroke mick · 04 June 2015, 14:50

Poly what sort of issues can arise from killing a diesel engine which is running at high speed apart from causing damage to a hot turbo bearing which is still spinning but not getting any oil to cool it?

TSM

willk · 04 June 2015, 16:58

Quote:

Originally Posted by two stroke mick

Poly what sort of issues can arise from killing a diesel engine which is running at high speed apart from causing damage to a hot turbo bearing which is still spinning but not getting any oil to cool it?

Think you answered your own question there Mick - ongoing stress on some of the exhaust system is cited by Yanmar too.

Poly · 04 June 2015, 17:16

Quote:

Originally Posted by two stroke mick

apart from causing damage to a hot turbo bearing which is still spinning but not getting any oil to cool it?

TSM

is that not expensive enough?

Daniel · 04 June 2015, 21:12

Totally aside to potential damage if misused...

If you have a stop button (think yanmar) or it stops on the key then it won't cost $400 to add a kill cord.

willk · 04 June 2015, 21:13

Quote:

Originally Posted by Daniel

Totally aside to potential damage if misused...

If you have a stop button (think yanmar) or it stops on the key then it won't cost $400 to add a kill cord.

Oh sure - £15 for a killswitch, even if it is crap

Daniel · 04 June 2015, 21:22

Perhaps spend £19 on a good one then...

willk · 04 June 2015, 21:25

Quote:

Originally Posted by Daniel

Perhaps spend £19 on a good one then...

Sorry D., my rollseyes were directed at a specific killswitch, not you...

beamishken · 04 June 2015, 22:57

Depending on the manufacturer of the engine some kill switches are live to kill & some are break circuit to kill either way it's a fairly simple wiring job
That's assuming it isn't an ancient pull cable to stop type engine then you have to add a solenoid but can't be many engines left like that
As for potential engine damage I'd rather risk my turbo going pop than get run down by my boat cos I didn't fit a kill switch in case it damaged my engine

Searider · 04 June 2015, 23:00

Quote:

Originally Posted by beamishken

Depending on the manufacturer of the engine some kill switches are live to kill & some are break circuit to kill either way it's a fairly simple wiring job
That's assuming it isn't an ancient pull cable to stop type engine then you have to add a solenoid but can't be many engines left like that
As for potential engine damage I'd rather risk my turbo going pop than get run down by my boat cos I didn't fit a kill switch in case it damaged my engine

Agree,
Would much rather buy a new turbo than have to face a Padstow type scenario.

ncp · 04 June 2015, 23:36

Quote:

Originally Posted by beamishken

Depending on the manufacturer of the engine some kill switches are live to kill & some are break circuit to kill either way it's a fairly simple wiring job
That's assuming it isn't an ancient pull cable to stop type engine then you have to add a solenoid but can't be many engines left like that
As for potential engine damage I'd rather risk my turbo going pop than get run down by my boat cos I didn't fit a kill switch in case it damaged my engine

Correct, the majority (probably 99%) of 7.3m Willards in private hands in the USA have a mechanical 5.9L 6BT Cummins engine that is stopped with a pull cable/t-handle.

This is the same engine that was in the Dodge/Ram trucks pre-2007 - but the solenoids on those are 12v, energize to run. US Navy Willards all run on 24v. Hence why clloyd had to custom order his solenoid.

zip · 05 June 2015, 02:06

and again,,,,Tom impresses me with his wealth of knowledge.

Pikey Dave · 05 June 2015, 09:49

Quote:

Originally Posted by Searider

Agree,

Would much rather buy a new turbo than have to face a Padstow type scenario.

Trouble is, it's not always an emergency scenario that leads to kill cord operation. I quite often inadvertently operate the KC when I forget to detach it when I'm helming, call it muppetry on my part, but it does happen, I wouldn't want to risk engine damage in a non-emergency situation.

.....sh1t happens.......

beamishken · 05 June 2015, 10:32

Quote:

Originally Posted by Pikey Dave

Trouble is, it's not always an emergency scenario that leads to kill cord operation. I quite often inadvertently operate the KC when I forget to detach it when I'm helming, call it muppetry on my part, but it does happen, I wouldn't want to risk engine damage in a non-emergency situation.

.....sh1t happens.......

Yeh but if it's a case where your going to detach it anyway ie tying up etc your going to be at low rpm & therefore no damage potential
The damage potential is fairly small & is realy only an issue at high load & rpm,at slow speed it's no worse than switching the engine off

Rokraider · 05 June 2015, 11:14

I have a kill cord on my Sabre 250 that is in the Pacific 22. It originally had a manual cable cut off. I simply fitted a solenoid that pulls the arm on the pump to turn it off when the ignition is turned off. It is quite straightfoward and just involves making a mounting plate for the solenoid to bolt to. As far as shutting down at high speed, all the time the engine is turning, so is the oil pump, so as it slows down, it is still pumping oil through the turbo bearings. It would be kinder to let the temperatures drop before shutting down, but it wont destroy the turbo. I would rather shut down at high speed and risk some minimal damage to the engine than watch the RIB roaring off without me, or worse still roaring towards me!