turning up the fuel on a ck27

[SPYDERLK]

SPYDER.. The injection pump is capable of producing more fuel than the engine manuf. requires for any given application.
That's to say, the same engine will have different HP's depending on the customers request.. The ENGINE manufacturer then turn a screw on the engine to produce the required HP..
The pump folks just make sure the inj. pump IS CAPABLE of producing that fuel from a spec sheet supplied by the PUMP manufacturer..
and ofcouse we set the equal delivery between cylinders.
If you take a gander at your engine you'll see a HI idle screw, a LOW idle screw and hidden screw w/ a tamperproof cap, a MAX fuel screw, AWAY FROM THE INJ. PUMP. That's a separate governoring system.. The pump just pumps the fuel quantity that the governor system tells it to. Its made up of springs and flyweights. [I hope this helped.]

Yes. I have previously set the "tamperproof" inward with good result [turbo tractor]. ... Ill be looking for that AWAY FROM THE PUMP SCREW to see if I can get firmer RPM holding. The rpm drops too much at a set throttle before the engine really buckles down and works. Its like it needs a quicker fuel advance.

 

[adventure bob]

So, I guess Id have to ask what the expected benefit of turning up the fuel pressure on your tractor is? What's the expected change you think you may be achieving? Id have to say that you have an injector rated at a certain number of gallons per hour at a given pressure. Turning up the pump increases the pressure but does not change the volume the injector can flow, the cycle at the injector i.e. pulse width and duration. The injector timing will be the same, the orifice size is the same, your just putting pressure more pressure behind it. You could calculate the increase in fuel volume (the thing that increases HP & Tq), assuming no negative affects on flow properties at the higher pressure. However given the same injector cycle at the gains will be nearly negligible, not to mention the flow issues at the higher pressures. To get Hp gains you have to change the injector cycle, and move up to larger injectors and increase rail pressure. Changing the injector cycle is what most tuners for pickups do.

 

[thepumpguysc]

Bob, you are mistaken. You ARE increasing the volume, so much so, you can flood the engine, melt a piston or wash down a cylinder.
The black smoke is the tell.. unburnt fuel escaping out the exhaust.
The pressure remains the same, controlled by the injectors.. The injectors are set at a determined pressure, set by the pump/engine manuf. and opens when it reaches that pressure, produced by the injection PUMP..
The AMOUNT of fuel injected, is determined by the inj. PUMP..
A noticeable/acceptable amount of increase in fuel, is 10% with no damage.
Like I posted earlier, the pump is CAPABLE of delivering more fuel than required by the engine manuf... THIS cuts down DRASTICALLY on pump manufacturing for each and every HP requirement by the customer..
Example> 1 PUMP = 3-4 different HP ratings..
I hope this helps..

 

[thepumpguysc]

You can increase the fuel to the point that the INJECTORS wont completely close and fuel dribbles into the cylinder instead of atomizing.
The excess fuel runs down onto and around the piston rings taking with it any lubrication.. Hence the term, washing down a cylinder.
A broken/blown tip on an injector w/ do the same thing.

 

[adventure bob]

Pump, If we were talking about a mechanical fuel injected engine from 30 years ago you might be close to correct.
We are talking about a CK27 with modern electronic engine control right? A common rail Daedong 3A engine? The computer controls the pulse width. The pressure on a common rail engine is NOT controlled by the injectors. Injectors are rated at lbs/hour at a given pressure Injectors are not "set" they are made; they are a computer controlled on off device with an orifice in the end. That orifice is "drilled" in the injector and cannot be changed after manufacture; thus injectors are rated in pound per hour based on the diameter of those holes. They are fixed and quite frankly you cant shove more **** through he goose.The pump provides pressure to the rail, that's it, the computer determines how long and when to open and close the injector. The injectors only open or close per the computer map. Having more pressure doesn't necessarily mean more volume. There's fluid flow properties to consider when you crank up pressure such as droplet size and spray patterns that do not get you a 1:1 increase in volume. Nothing you can do at the pump changes the holes in the injector or how the computer commands the injector timing cycle. Look up a bosch injector, and basics of electronic fuel injection. His 3A actually has multiple injector cycles per combustion event.

2nd you will never melt a piston by providing too much fuel; that's the exact opposite of what you do and why you get black smoke. You will actually cool the combustion chamber, not make it hotter by over fueling. You have provided more fuel than the stoichiometry can support and if work through the stoichiometry equation you'll see that the heat of combustion is lower lower rather than higher.

 

[thepumpguysc]

You my friend are correct.. we were talking apples and oranges..

 

[jabelding]

All older straight CK series have a mechanical injection pump even my 2014 CK35 is a mechanical injection pump. They didn't go to the ECM injection until the tier 4 engines CK2710 CK3510.

 

[vidio1]

I think some of the confusion is thinking of a diesel like a gas burner. They don't react to an increase in fuel the same way.

 

[thepumpguysc]

I started posting about a "mechanical" fuel injection system.. and Bob started talking about a "common rail" electronically controlled, fuel injection system.. 2 completely different animals..
Sorry for any confusion..

 

[adventure bob]

So what's the OP have? It looks from his pic to be modern. This is germane to the conversation....
and oil burners do react to increases in fuel like gas engines. There's basic physics involved here: Theres X amount of btus per volume of fuel and it needs to be mixed in the right stoichiometric ratio with O2 and ignited for it to release the energy. Its exactly the same. The only difference is that diesel is ignited under compression and gas requires an outside energy source to start the combustion. This basic process is the same for ALL oxidized chemical reactions. Add more fuel, you need more air or you get outside of the stoichiometry and the process doesn't release all of the energy in the fuel. Add more air without adding more fuel, same problem. You can mess the equation up to either side and the engine wont run.

 

[thepumpguysc]

OOOHHH.. IT LOOKS LIKE..
Your right.. it IS germane..
BUT the SIMPLE ANSWER is YES with the turn of a screw or a computer the hp CAN be changed.
Momma said thered be days like this..
that's what I get for being a Jenius.. :laughing:

 

[SPYDERLK]

So what's the OP have? It looks from his pic to be modern. This is germane to the conversation....
and oil burners do react to increases in fuel like gas engines. There's basic physics involved here: Theres X amount of btus per volume of fuel and it needs to be mixed in the right stoichiometric ratio with O2 and ignited for it to release the energy. Its exactly the same. The only difference is that diesel is ignited under compression and gas requires an outside energy source to start the combustion. This basic process is the same for ALL oxidized chemical reactions. Add more fuel, you need more air or you get outside of the stoichiometry and the process doesn't release all of the energy in the fuel. Add more air without adding more fuel, same problem. You can mess the equation up to either side and the engine wont run.

Adding more air in a diesel is not the same, or any, problem. They always take a full lungful of air and moderate the fuel for needed power -- up to the max burnable in the air charge. This is due to the fuel being injected into a hot dense O2 rich environment.

 

[dfkrug]

All older straight CK series have a mechanical injection pump even my
2014 CK35 is a mechanical injection pump. They didn't go to the ECM injection until the tier 4
engines CK2710 CK3510.

You are correct: all these M27 tractors have mechanical FI, CK25/27/30/35, CT225/230/235. The
DaeDong xx10s are electronic.

As for increasing the pressure of a fluid thru a fixed orifice, that always increases the flow rate (volume).
That basic principle of hydraulics also applies if you put a spring and needle valve in there so that
the flow does not start until the pressure overcomes the spring, as in a mechanical injector.

 

[adventure bob]

DF id agree that on paper the straight math says that. Fluid dynamics however would show some seriously negative effects on flow characteristics with regard to decent burning, as the pressure goes up. An increase in pressure doesn't always result in flow characteristics that are appropriate for combustion. Yep more fuel may go through but if goes through in a stream its pretty much going to hamper combustion, not help it. Additionally fuel at the higher pressure may have a negative effect on the propagating flame front.

In the mechanical poppet style, isn't it possible to increase the fuel pressure so that you inadvertently alter injection timing? Essentially injecting too much fuel too early?

 

[dfkrug]

In the mechanical poppet style, isn't it possible to increase the fuel pressure so that you inadvertently alter
injection timing? Essentially injecting too much fuel too early?

There are several variables at play here, not just pressure and volume. If you are adjusting for more volume
in a diesel FI system, as PUMP points out above, then your pressure is not usually variable. Clearly
there are limits to the adjustments available within some narrow range. Timing of these mechanical
pumps is often pretty simple: on my JDs, you just loosened a couple of bolts and rotated
the whole pump a few degrees either way about its input shaft axis.

I have yet to mess around with my Kioti FI system.

 

[adventure bob]

It appears that cranking up the fuel pressure on a Cummins with a p7100 pump was pretty easy as well, just don't know how in those mechanical systems you adjust for fuel event timing. If its sucking in a certain volume of air and you just throw more fuel in, or worse more fuel in earlier, what does that get you other than cylinder quench? I fully appreciate electronic fuel control much more now...

 

[ritcheyvs]

Maybe this will help explain mechanically-injected Diesels.

As far as I can tell only the xx10 models have common rail (electric) injection systems.

 

[dfkrug]

I fully appreciate electronic fuel control much more now...

You can do a lot more with electronic-controlled diesel FI, tho the parts cost more. The solenoid-operated
injectors can fire multiple times on one stroke, and run 10 times the pressure of a mechanically-injected
system.

 

[thepumpguysc]

Can anyone tell me what this has to do w/ the question originally asked??
This is a HELP FORUM.. not a keyboard engineering class.. start your own thread..

 

[Amvcane]

Where's Fred and his hair dryer?