Turbocharging a Jinma 254 Build (Y385)

[cleat]

I believe you are correct. In a gas engine when the throttle plates are suddenly closed a blowoff valve is used to dump the excess pressure.

Cleat

 

[D0TC0M]

Here is a picture of the back of the injection pump. I have marked out on the picture the high and low speed adjustment for RPM and the third adjustment is on the back of the pump is fuel? The manual said there are three adjustments that are wired together so deductive reasoning would suggest that it is the max fuel screw on the back (it should increase the max travel of the rack).

That matches up with the info I have read on a few other threads; that it is the fuel screw.

View attachment 433267

I have a 2009 FOTON 254 with a Laidong KM385 engine.
When I bought my tractor I talk to a mechanic who repairs farm equipment at the farm. He said that there are simple machine but some had their fuel pump not set to achieve the engine the horse-power it should. He told me that it is mostly true for the FT404 ( tractor won't hold speed in 8th gear ) and the dealer near by (close now ) ask him to put the tractor they sell on his dynamometer.

So, one morning I go to his home and he put my tractor on his dynamometer. At that time the engine show around 22HP at the PTO that is not too bad for a 25HP tractor. He said that he could adjust it a little bit more but not to a point there is black smoke. Now the engine have around 32HP with the exhaust nearly clear.

The adjustment are the one you point in the pic. As I remember the max fuel have two screws. One outer bigger for the rack travel ( HP ) and middle one for fine tuning or a buffer screw ( not sure ) that he just slightly adjust.

The maximum RPM should not be over 2500.

I like this thread very informative and I hope you can take a video of the tractor running, earing that turbo whistling . :thumbsup:

Jacques

Seems that these engines may have been restricted to meet emission regulations and that possible HP gains could be possible by adjusting the fuel screw. Jacques or Electro Technics could you elaborate a little more about this fuel screw and possibly how to adjust it.

Electro Technics how is your turbo project making out? any updates?

 

[jacques54]

Hello DC,

The adjustment is the one ( FUEL ?) in Elec. Tec.'s you atach in the reply above. It have a lead seal on the end cap that should be remove to take off that cap. The adjustment limit the travel of the rack of the plungers that push the fuel. Backing it off add more fuel to the injectors. But if you don't have a dynamometer you don't know what you are doing . If you go too far you will emit too much black smoke and not gaining much HP. If you keep the engine in full load for too long it maybe melt a piston. Do I care too much, I don't know, but maybe.

Regard
Jacques

 

[D0TC0M]

Well I don't want to push it. Seems to me electro technics said you could adjust it 1/2- to one turn no problem. Maybe I'll install a EGT temp probe in one of the exhaust just to be sure. How long does the engine have to run at full load to achieve a stable exhaust temperature?

 

[jacques54]

How long does the engine have to run at full load to achieve a stable exhaust temperature?

A EGT is it the same as a pirometer gauge?
I never use an EGT gauge to adjust fuel output (?) (debit F). The max. exhaust temperature should be when the engine reach the max. HP output.
I would like to add a curve chart of a diesel engine HP vs RPM vs fuel consumption and if possible vs exhaust gas temp. On the net there is lots of these chart and finding one would take too much time to find the right one.

When I was working in an engine rebuilding shop I had to test engine on dynamometer (40 years ago). What I remember,
Ex. An engine at full trottle no load reach 2150 RPM then I add load until the engine drop to 1800 RMP, at max. HP reading. You should see the turbo exhaust side become red. Then after five minutes I reduce the load and let idle to cool down. The black smoke mostly come when you are at full trottle and the load increase until RPM drop toward engine max. torq (around 1300 RPM depending (?) on engine own specs).
Maybe I am not up to date on newer engine but basic of operation should be close.

Jacques

 

[D0TC0M]

A pyrometer is a infrared meter that measures temperatures externally. A EGT Gauge is a physical thermocouple sensor that you insert through a hole in the exhaust manifold to directly measure exhaust gas temperature. I've used this type of gauge a lot during my skidoo racing days. I have an infrared camera I could use if you think a pyrometer will work.

The fuel screw with the lead seal, do I unscrew (screw out) to increase fuel

 

[jacques54]

The fuel screw with the lead seal, do I unscrew (screw out) to increase fuel

What I had wrote in the 63 reply above,

The adjustment limit the travel of the rack of the plungers that push the fuel.

Yes, backing it out let the rack going further and increase fuel delevry.

I think if you did Ski-Doo racing you know how to play with fuel output. Worth a try and let me know what is the results.

Jacques

 

[D0TC0M]

Hey Jacques I took the cap off the fuel screw. It looks like it has 3 adjustments. Can you confirm which adjuster to turn? I'm assuming the 3rd adjuster in the pic below. What does each adjuster do? Not sure if the 2nd one is an adjuster or not.

 

[Bob Rooks]

:laughing::laughing::cool2::cool2::dance1::dance1::thumbsup:

 

[jacques54]

Yes, Bob you are right and that is why when I wish to know the tractor output I take the whole machine to a guy who have the equipment and did play with those adjustment before.

Dotcom, tomorrow I will scan the pages of the engine related to these adjustments then post them. It don't look simple.

Jacques