Fuel Shut Off For 24/2

[Jsw]

Jsw:
In your earlier post you mention your plan to use of the engine control/monitor hardware. I did download the manual and browse it- it looks like a decent unit.

Given its capability for remote start, like the venerable SOM,  you'll need both decompression and rack closing for normal start up and shut down, and that will certainly suffice for emergency shut down as well.  Air shut off doesn't get you anything but emergency shut down, and rudely at that (fuel still being injected for a minute as the flywheels slow down).

I like the air cylinder actuators for my application, they are cheap, reliable, and powerful, but I realize most guys don't have air. 

My engine was custom designed and has a very powerful starter on it. (delco Remy 42MT) I can easily start it without decompression.


I would like to avoid rack closing due to the extra fabrication. Instead I hope to use two solenoid valves (one per cylinder) as well as an electric solenoid for decompression at shut down. I have a 24/2 by Poweranand. Does this sound like a plan?

You say that air intake shut down is a "rude" one. Is decompression any better, though since neither one shuts off the fuel?

[mike90045]

Lifting the fuel lever, cuts the fuel off, but would not help if engine is sucking crankcase oil.

But can a cable be attached to the fuel lever, and used for emg stop ?  Any reason not to attach a remote cable to it?

[BruceM]

Jsw-  Be forewarned that some fuel solenoids will not work- the suction of the IP is too great.  (I tried and failed with this approach). Further, there is some question as to whether this is bad for the IP, as it will cause cavitation. 

The fabrication for a rack closer isn't much - mine is a single piece of bent iron strap  I suggest not messing with the fuel, and doing it right (rack closer).

Sure, either secondary method such as decompression or air cutoff would be fine for emergency shut down, as backup to rack closing, since your starter doesn't need decompression.

[Jsw]

Jsw-  Be forewarned that some fuel solenoids will not work- the suction of the IP is too great.  (I tried and failed with this approach). Further, there is some question as to whether this is bad for the IP, as it will cause cavitation. 

Could you explain to me what you mean by "IP"

Also will it cause damage to the engine in any way to just use a air intake shut down as a regular way of shutting down.

[lowspeedlife]

IP = injection pump

  SR

[vdubnut62]

In my opinion, cutting the air off will cause no permanent damage to the engine, it's a traditional and time honored method of stopping
a runaway diesel right now!
Ron

[BruceM]

Air cutoff as the sole normal shutdown on a lister/oid would cause your two injection pumps to keep doing fuel injection until the flywheels stop, which can be a full minute and a fair amount of fuel.  That's fine for an emergency shut down, but I don't like it for  normal operation shut down. 

[mobile_bob]

Bruce:

just asking because i don't know

do you really think it would take more than 10 seconds or so to come to a stop with the intake cut off?
seems like with the engine now being converted into a huge vacuum pump it should suck up a lot of power
and drag the engine down much faster than simply cutting off the fuel and coasting down to a stop?

your point about the injector continueing to pump fuel is a valid one, however.

bob g

[Capt Fred]

Howdy Bob

I've actuated mine several times (experimental only) and it does take (what seems to be) quite a while to come to a stop something in the area of  10 seconds more or less -  I'd guess heavy flywheels have something to do with it. before I got the intake properly sealed , it would slow way way down but not quite stop running  - eventually had to  shut it down by lever.

As for the solenoid operating the IP for shutdown - i've got over 1200 hours running time with a murphy solenoid - no problems with the pump - so far anyway.

  MURPHY SOLENOID

For emergency shutdown the system works fine with only one solenoid operating only one IP.  No solenoid for decompression - I figure I want the bloody thing shut down when something goes south.  After a coupla overheat(s) (my fault) the engine shut down flawlessly.  How often do you need emergency shutdown due to overheat etc - not very often i would hope - so how many redundant systems are really needed (IP shutdown, decompression shutdown, air shutdown etc)

My air shutdown is intended for runaway or other bad things where I might want to shutdown the engine from a distance (outside the space).

After running the engine I like being on site for shutdown - look for leaks (oil fuel exhaust etc) and other possible problems  - turn the key switch to the solenoid and let the engine wind down then set the decompression levers.

FWIW - Speaking of air shutdown -  lifevests (lifejackets) will keep you afloat but also come in handy smothering a screamin' jimmy.

Cheers, Fred

[vdubnut62]

Okay. Point taken Bruce & Mobile_Bob, I should have said emergency shutdown, the raw diesel being injected wouldn't do the cylinders a lot of good on a continuous basis.
Ron

[BruceM]

Bob, I was thinking a minute of coasting and injector squirting as that's what my 6/1 takes to coast to a stop with decompression.  It would certainly be much less with compression and pulling vacuum on the intake.  Thanks for the correction!

The Murphy rack closer solenoid is an ideal solution for normal ops shut down;  Fred has a first class setup.