Diesel fuel cut-off solenoid

[coopec43]

I'd like to be able to turn the Perkins diesel engine off at the helm. I thought of using a bowden cable but I don't think that would be wise in a marine environment.

There are a lot of fuel cut-off solenoids on eBay but their price is hideous. Some are described as 12V/24V while most others are described as 12V. Would I be pushing my luck using a 12V solenoid in a 24V system?

I know the subject of solenoids came up on a thread a couple of months ago and someone suggested using a "General Purpose solenoid" and actually gave the make/model of the unit. My system is 24V: can anyone suggest a suitable inexpensive solenoid?


Clive

[Q Xopa]

Originally Posted by coopec43

I'd like to be able to turn the Perkins diesel engine off at the helm. I thought of using a bowden cable but I don't think that would be wise in a marine environment.

There are a lot of fuel cut-off solenoids on eBay but their price is hideous. Some are described as 12V/24V while most others are described as 12V. Would I be pushing my luck using a 12V solenoid in a 24V system?

I know the subject of solenoids came up on a thread a couple of months ago and someone suggested using a "General Purpose solenoid" and actually gave the make/model of the unit. My system is 24V: can anyone suggest a suitable inexpensive solenoid?


Clive

Is this intended for the regular shut off or emergency shut off, for a runaway etc?

If for emergency I would suggest an air intake shut off as being better.

The reason is a runaway engine may be running on another source of fuel, like sump oil a leaky fuel line find its way into the intake etc. So shutting off the regular engine fuel supply still wont stop it.

[coopec43]

Originally Posted by Q Xopa

Is this intended for the regular shut off or emergency shut off, for a runaway etc.
If for emergency I would suggest an air intake shut off as being better.

The reason is a runaway engine may be running on another source of fuel, like sump oil a leaky fuel line find its way into the intake etc. So shutting off the regular engine fuel supply still wont stop it.

Wow! I didn't think of that: food for thought....

No, I was thinking of regular shut off.

Thanks

[Pete7]

Originally Posted by Q Xopa

If for emergency I would suggest an air intake shut off as being better.

I fitted one of these to a Ford Dover (lehman type) 4.2 litre diesel engine on a large rib. The steel flap was operated by a solenoid and a outboard deadmans switch on the dash. Worked well and would stop the engine immediately if you fell over board, the intended use. The solenoid required power to hold the flap open so in the event of an electrical failure it would shut. Manual over ride required a bolt to be removed and the flap opened to allow the engine to run.

Pete

[jimbunyard]

Not entirely sure why you think a cable is unsatisfactory for a marine application; doesn't your throttle operate via one? I can understand from an ease-of-installation standpoint, wires can be a lot easier to install than cables (sometimes), but I like the keep-it-simple approach of cable actuation.

However, if you search for '24v stop solenoid" a myriad of choices come up for 50.00 - 75.00 US, which is close enough to the price of a long Morse cable.

A couple of examples;


https://www.amazon.com/Blueview-sole.../dp/B00LGJA0YA



https://www.amazon.com/Holdwell-Shut.../dp/B00MIDQHPY

[coopec43]

Originally Posted by Pete7

I fitted one of these to a Ford Dover (lehman type) 4.2 litre diesel engine on a large rib. The steel flap was operated by a solenoid and a outboard Worked well and would stop the engine immediately if you fell over board, the intended use. The solenoid required power to hold the flap open so in the event of an electrical failure it would shut. Manual over ride required a bolt to be removed and the flap opened to allow the engine to run.

Pete

I'll think about what you have done.

" deadmans switch on the dash." something else to think about too......


I'm always looking for a cheap way out (where it doesn't compromise safety) so I've been looking on eBay for a solution. As soon as I searched for "Push/Pull solenoid" there was any amount of them for sale from $2.61 upwards!

[coopec43]

There are plenty to choose from. Maybe a car door lock solenoid?

[fish53]

A flap for the intake is slightly more engineering than a shut down solenoid but certainly useful. If you consider both, a cable for an emergency shut down and a solenoid for normal shutdown might be best. Truth is few diesels these days run away unless the rings are extremely worn in which case the lack of compression would make it hard to start as well as smoke. I have a shutdown solenoid on my Lister Petter which works find, what you want is a solenoid that when deenergized closes the fuel rack, that way with the key off fuel is prevented from entering the injection pump. Solenoids come both ways extended when deenergized and collapsed when the same.

[Q Xopa]

I'm not sure of your boat engine cockpit layout, but you cant just do a 'Push/ pull rod', even with a bell crank to change direction etc, can you?

Yes the butterfly valve/ flap type ones come in various different flavours like manual cable/ electronic controlled with eith electric or hydraulic actuated etc

These are good and certainly better than what most people have which is naught.

However I like these ones AMOT-Products- Automatic Self-Contained Valves-D and D-AM Automatic Valve as they have no cables, electronics etc to fail, can be set up for your engine and automatically reset. They simply work on airflow and when the airflow flowing through it to run your engine at max RPM is exceeded, they close and shut your engine down.

This is something most people dont think of until we are faced with a runaway engine screaming it's self to death, unable to shut it down. Thankfully it's not that common.

[fish53]

I should point out that on my old Perkins 4-108 I simply ran a small piece of line from the fuel shut off to the pilothouse and a spring to return the lever which should be there anyway. Pull the line, engine shuts down, simple and cheap.

[coopec43]

Originally Posted by fish53

what you want is a solenoid that when deenergized closes the fuel rack, that way with the key off fuel is prevented from entering the injection pump. Solenoids come both ways extended when deenergized and collapsed when the same.

Stacks of good information being posted.

I was just getting around to thinking about how it would work and obviously when it is de-energised it will have to close the rack.

Thanks

[a64pilot]

You can do interesting things with a solenoid.
In the late 70’s I rigged up an electric shift for motorcycle drag racing with a washing machine solenoid, I tried a starter solenoid first, but It bent the shift forks, those things are strong.
The Murdock air shifter was the slick item back then, but it was large requiring an air tank and complex, and of course required an air compressor to refill the air tank.
So don’t get a God awful strong solenoid, they can break things

[coopec43]

Originally Posted by a64pilot

So don’t get a God awful strong solenoid, they can break things

Your advice noted!

After Fish53 said
"what you want is a solenoid that when deenergized closes the fuel rack, that way with the key off fuel is prevented from entering the injection pump"

I realised some of the solenoids I was looking at are no good as they can't be left on while the engine is running.

I can think of no reason why a remote car door lock would not be perfect.

[a64pilot]

Originally Posted by coopec43

I can think of no reason why a remote car door lock would not be perfect.

If you want one to be fail safe, that is no power, solenoid spring returns fuel to off, then you are going to have to have a 100% duty cycle solenoid, which I’m sure a door lock solenoid isn’t, most are not, you have to find one that won’t overheat when powered all of the time.

However I don’t think you need one that when deenergized fuel is off, my reasoning is that the factory Yanmar fuel shut off solenoid isn’t that way, it’s deenergized fuel is on, energized is off.
Plus I think the door lock is way stronger than you need, pull the fuel shut off with your finger, most take very little force to move at all.

If you have one that requires power for the engine to run, then you can lose your engine from multiple failures, I wouldn’t want that myself.

[fish53]

Originally Posted by a64pilot

If you want one to be fail safe, that is no power, solenoid spring returns fuel to off, then you are going to have to have a 100% duty cycle solenoid, which I’m sure a door lock solenoid isn’t, most are not, you have to find one that won’t overheat when powered all of the time.

However I don’t think you need one that when deenergized fuel is off, my reasoning is that the factory Yanmar fuel shut off solenoid isn’t that way, it’s deenergized fuel is on, energized is off.
Plus I think the door lock is way stronger than you need, pull the fuel shut off with your finger, most take very little force to move at all.

If you have one that requires power for the engine to run, then you can lose your engine from multiple failures, I wouldn’t want that myself.

I wouldn't want to leave a boat very long with any electrical device energized. Certainly you can have a separate shutdown switch for momentary use. In the event of a solenoid failure you can just wire the fuel control open. A solenoid is simply an electromagnet not an electric motor like an electric fuel pump that has no trouble running for hours and hours.