Robert this is the #1 engine, #2 was the one rebuilt 7 years ago.

And not to be a smarta$$ but I know perfectly well how a governor works and the theory behind it. They serve the same function on small engines of which I have quite a bit of experience. And believe me a Kohler K-121 will eventually grenade itself if you bypass the governor(seen it happen) and pull the throttle wide open. Hence the reason for 4000 RPM restrictions in stock class garden tractor pulls, and they check it before you run at most events. If you go above that you have to put custom internals into the block that are better balanced and made of stronger materials then cast iron. But by that time you have a billet machined flywheel with no fan and probably a custom block as well. Oh and an empty wallet.

Yeah and don't forget the mandatory shrapnel shielding, fire suit and fire suppression system.

I am wondering if robert is explaining the type of governor, more so than governors in general. Most people do not know that there are different types (not manufacturers) of governors, that change the way the throttle and engine react together. Those familiar with Detroit Diesels have probably seen this more than anybody.
DD classifies the most popular like this:

Variable Speed, like a tractor, or Kohler engine, tries to maintain the rpm that you set between idle and wot. Even tries to maintain idle under load.

Limiting Speed, basically gives you direct control of the fuel rack until a set top rpm is reached. Idle is a set position on rack, so if you load it at idle, it can stall out. These are used mostly in trucks, busses and other or vehicles.

Constant Speed, think generator. Set to run 1800 or 3600 or such.

Dual Range, I think these were used on marine applications, and maybe some coaches.

You have to be careful in swapping some engines because of this. And understanding how your throttle and engine respond together.

I just called Scat. I didn't have a real good description of what it might cost, but a large (i said 6-8 foot long) V8 diesel crank he said in the $5k range. Not all that bad....

Does that include the reverse engineering from the scrap crank? I really doubt CAT would just voluntarily give you the prints for that crank.

But I do know of 2 or 3 d17000 blocks with potentially good cranks in them if the need arises.

That is true, but you aren't relying on the governor overspeed the way you'd have to (unsuccessfully in many situations!) with something like a truck diesel: this engine is connected to a generator, and a very simple application of additional field current with an appropriate short time constant into an emergency load ... which under the circumstances might be little or no more than the traction motors ... would do the business long enough to pull an emergency fuel shutoff (or induction air flap, perhaps) no matter how much residual fuel is in the lines. I'm surprised this isn't standard procedure on any 'irreplaceable' diesel-electric set.

Likewise, the well-established problem with instantaneous overspeed of highly-loaded truck engines is unlikely to occur on a diesel-electric because there is no analogue to breaking a driveshaft and instantly unloading the engine at high developed power -- i assume the generator is direct-coupled and there is no way for the generator field to drop immediately to zero even if the output connections are interrupted.

Having said that -- I can't imagine that anyone would start the engine again even once with a known sticking-rack problem, even to 'test if it's fixed' ... I'd take the governor off, and load-test it exhaustively on the bench when done working on it before reinstalling it. I'd also establish a checklist for engine startup that requires checking, and logging, the governor oil level before any attempt is made to start (or restart) the engine...

Blown fuses, burned wires, loosing the field relay, contacts on the throttle or reverser, loosing the battery voltage, tons others, could cause a sudden and basically complete loss of main generator loading. Not to mention 'jamming it in gear' may be dangerous depending on what you are pulling and where you will be going. Also if you have to do it AFTER the engine is already up in RPM you are gonna put one heck of a shock on the system, like sidestepping a clutch when you have the throttle firewalled. The magic dancing pixies in the wires may violently disperse carrying molten metal with 'em.

Cutting the fuel will eventually kill the engine of course, but if you have ABSOLUTELY ANY reason to suspect that the engine may run away, you should pull ALL the air cleaners off where you are left with a flange that you can put a flat piece of plywood over the opening and snuff off the air. Cut and fit those plywood pieces in advance, usually made like a ping-pong paddle (you do NOT want to get your fingers caught under the plywood!). In case of a runaway, cut off the air, and that will instantly kill the engine. The plywood should attach themselves from engine vacuum . Be aware you will probably get some very thick smoke out of the exhaust.

I agree that cutting off the air supply is the way to stop a runaway diesel. Another method to cut off the air supply is to spray CO2 in the air inlet. Just be sure you have enough of it.

My father was present at a test of the next generation FM Diesel engine Intended for locomotive service. The engine ran away and the rods came out through the sides of the block. They ran out of CO2 before the engine came to a full stop. Apparently it was running on crankcase oil as the fuel cutoff had no effect. FM management was unwilling to spend the money for another prototype engine so that was the end of FMs locomotive business.

I was taught in the Army that one of the best ways to stop a runaway diesel, like on a deuce-and-a half or five ton, was to wrap your fatigue shirt around the air cleaner mushroom, cutting off the air supply. My eldest son is in the Coast Guard, and was telling me that one of the cutters he was on had plates that could be placed over the intake filters, doing the same thing.

Update on progress.

We were able to get the mechanism freed up Saturday with the help of a gallon or so of ATF and a lot of elbow grease. Disconnecting the linkage and opening the top hatch was a huge help.

Unfortunately my fat a$$ still does not fit well and I discovered new muscles to scream in pain by the end of the day.

We did lose some of the ATF into the engine oil or somewhere as the actual governor is in a separate chamber and the ATF leaked out over a couple of hours. The drain line out of the injector pump is plugged solid so we were unable to get the ATF out of that chamber. We tried back flushing with compressed air to no avail. The upper end of the drain line is basically inaccessible without removing the pump. I left the cap off the line and it was dripping slowly so in a week hopefully it will drain completely.

We did try to start the engine however it will not fire on anything but either. I was afraid of doing more harm with the either so we stopped after a few tries. This engine is notorious for hard starting even in warm weather(this weekend was 60+ and sunny.)

I guess the next step is to get an actual diesel mechanic out to adjust the injectors and rack. At least the governor linkages are now free.

At this point I am at a loss of anything to try next as diesel mechanics is outside of my bag of tricks. I much prefer engines with less then 4 cylinders and air cooled.

On the D17000, the governor is a separate section and housing from the fuel pump itself. The fuel pump can be removed from the governor housing while still installed on the engine without disassembling the front of the engine. If you wanted to remove the governor housing then yes, you would have to disassemble the front of the engine. I'm not saying its easy, simply because of the limited space under the hood, but it can be done. The governor is oiled from the engine oil system. The governor oil is returned to the engine crank case via the oil drain hole at the bottom front of the governor housing through the front cover as seen in this picture.



The fuel pump is a self contained unit with it's own oil sump. The fuel rack is internal in the fuel pump. The seal that separates the governor from the fuel pump is in the back of the governor housing along with the dipstick to check the oil level in the fuel pump housing. The governor directly controls the fuel rack in the fuel pump. Depending on the year there might be one of a couple different types of automatic shut down mechanism mounted to the back of the pump housing.



If the drain line for the fuel pump is plugged, you would NOT want to us compressed air to blow everything back into the fuel pump. All that would accomplish is getting all that crud scattered all over inside the fuel pump and would make it a royal pain to try and clean out. If it's not cleaned out thoroughly, it will cause excessive wear and eventual failure of the pump.

The injectors themselves have nothing adjustable. Likewise with the injector pumps on top the pump housing and the rack inside the pump housing. The only things adjustable would be your low and high idles. Those are done internal in the governor.

Bill

if you have a plugged return line, that alone can cause a runaway.

About a month ago we freed up the rack with some acetone and ATF and it did eventually drain out. We tried to start the engine afterwards and only able to get it to run on either. We stopped after that and have not tried since.

In my opinion we need to send the injector rack out to a rebuild house and have it thoroughly gone through. We are about to take the loco out of service for truck work and hopefully we will find a mechanic who can take a look at it for us.

That seems like a very good idea.

Regarding which engine was overhauled, both were overhauled. I may have gotten the dates mixed up on which engine.

As far as crankshafts to send to California for measurements, look what I ran across this at a museum in California.
Notice it's a flat crank - no twists. Bolt-on counterweights. Lends itself to being cut out of billet.