Diesel engine : Kromhout Gardner 4LW 1940

[minh-thanh]

Hi Everybody .
An update:
" You died in the game , you get a new life and continue game "
I made a new valve block, I decided to use aluminum because I ran out of brass. Using aluminum or brass as the valve block I think it doesn't matter
First valve block the holes are not concentric , I think it's a matter of making the valve sometimes closed and sometimes not , and I have also changed a bit .. and also positioned and drilled the holes more accurately...hopefully this time will be good enough .

 

[minh-thanh]

Hi Everybody .
An update:
Maybe I solved the ball valve problem
Fuel pump worked , the part to adjust the amount of fuel for each injector : works quite well and I'm adjusting the amount of fuel, I will try to equalize the amount of fuel for each injector,

 

[Mechanicboy]

Hi Everybody .
An update:
Maybe I solved the ball valve problem
Fuel pump worked , the part to adjust the amount of fuel for each injector : works quite well and I'm adjusting the amount of fuel, I will try to equalize the amount of fuel for each injector,

View attachment 147422

View attachment 147423

Check the timing must be exactly same for each pumps to be sure the each get right timing, since the engine is 4 cylinder then it begins to end in timing 0-90-180-270. Use degree disc on the fuel injection pump and check carefully when the pump begins to pumping the fuel 0-90-180-270. If fault: incorrect timing of camshaft for injection pump, clearance between cam/pump piston to example fault in the amount regulator between pump/cam.

To check amount of fuel vs counts of pump stroke: Use syringe I'm millilitres without piston + injection pipe to drip fuel into the open syringe to measure millilitre of fuel amounts. Rotate the fuel pump in 300 turns and compare the fuel amounts are same in each syringes. Both in "idling" and "full throttle" position the amount of fuel must be same in all pumps measured I'm millilitres. If difference between the pumps, adjust the fuel amount regulator for this pump who has less/more fuel than other pumps.

 

[minh-thanh]

I know what you said , but the big problem is : it is not possible to adjust a very small amount of fuel , about 0.1 , 0.15 or 0.2 mm3 for each injector , I'm just trying to adjust a relatively equal amount of fuel.
With a small diesel engine, there are many factors that I cannot control, especially the parameters ...of the springs in the injectors and in the ball valve system.

 

[Mechanicboy]

I think you misunderstood me. Also not measure per pump stroke and check quantity. So you have to pump 300 times (300 revolutions on the pump shaft of the injection pump) and measure the amount of fuel on each measuring cup of the syringe without piston and compare with all the pumps delivering roughly the same amount in milliliters. The same thing we did with the injection diesel pump for vehicles when we measured the total amount after a certain number of spins and compared with all the pumps delivering roughly the same amount of diesel in the measuring cups in cm³.

 

[minh-thanh]

Hi All !
Just a small update
From the last post until now , I'm a bit busy so the engine is still on the shelf, I'll be back with the project in a few days.

 

[minh-thanh]

Hi All !
Just a small update
Today I can return to the project
A video when I was adjusting the amount of fuel
The results seem pretty good

The video is a bit shaky...please sit down while watching

 

[Roger B]

Looking good
Can you judge how even the injection timing is?

 

[minh-thanh]

Roger !
Thank you .

Can you judge how even the injection timing is?

...You always ask difficult questions for me
The way I do it with this engine and the others I've done: don't put all the standards of big engines into a tiny engine that I can do.
With a single cylinder engine, I know the injection time is between 22 and 45 degrees before TDC, so with this engine I will set the injection time to 30 degrees before TDC and then the injection time of all 4 injectors is between 22 and 30 degrees before TDC
Note: injection time is the time the lobe begins to come into contact with the plunger
injection time : injector 1 - 30 degrees, injector 2 - 27degrees, injector 3 - 20 degrees and injector 4 - 25 degrees, the engine will still run.
the same injection time of the injectors is almost impossible for me

 

[minh-thanh]

Hi All !
An update:
I want to learn more.. because there are some things that I don't understand so I changed the ball valve system with the system used in my 1 cylinder engine, including the inlet port and the ball valve.
There is an advantage to testing with all 4 cylinders at once: Just switching back and forth between cylinders in the same test is easy to come to an accurate conclusion.
Hope it helps someone

 

[minh-thanh]

Hi All !
An update:
With a mistake , a stripped thread hole

After assembling and testing, everything seems fine
I tried with the injector, injector spring seems weak

 

[Shelton]

What a very nice job you are doing.

 

[minh-thanh]

What a very nice job you are doing.

Thank you !
it's slowly draining my patience ..

Hi All !
An update:

With a single cylinder engine, I tested the injectors with the engine's own fuel pump, but with this engine I had to make an auxiliary pump to test the injectors.
This auxiliary pump has a mechanical part to limit the stroke of the plunger

 

[Roger B]

A test pump is always useful/helpful

I would suggest that you turn it round so that the plunger is horizontal and the fuel inlet is on top. This makes it much easier to get the air out of the system. The fuel tank is about 0.5m above the pump.

 

[minh-thanh]

Hi Roger !

It's not a problem to get the gas out of the system, just a little w20 or 40 oil and pump it into the system is fine.
One thing I don't understand is why the height of your gas tank and mine is different, my fuel tank is a little lower or higher than the pump, it doesn't matter.

 

[Roger B]

The tank height is not so much of a problem with diesel fuel. A volatile fuel like petrol needs to be under pressure at the pump inlet. I have been working with both fuels and keep the same height (the tank is fastened with a convenient screw on the head of my milling machine).

 

[minh-thanh]

Hi All !
An update !
I redo the injector spring
maybe....I made almost 100 kinds of springs to test ball valves and injectors with this engine

 

[Shelton]

You MADE the springs?!? Very neat indeed.

 

[minh-thanh]

You MADE the springs?!?

Yes I make springs
As shown in the picture, you can see that only the outside is grinded, if not is grinded , the outer diameter of the spring will be approximately equal to the inner diameter of the injector body.
How I make a spring - I will have a post about it - after I consider it at least good enough for homemade injectors

 

[petertha]

What are you guys using for that very small diameter copper tubing & how do you make the connecting ends into a larger body like a housing or injector? I've been thinking about future engine with lubrication oil pump & this is (yet another) uncharted waters consideration.