Diesel engine : Kromhout Gardner 4LW 1940

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minh-thanh

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Hard to tell from the picture but is the lapping tool split?
I'm a bit late to reply, sorry.

No, it's not necessary
I sharpened it to the angle of the needle and sharpened it with a file - making a place for the abrasive to stay - it's made of steel
I tried with aluminum, but it's too hard to do and it wears out too fast
 

minh-thanh

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Hi All !
An update

I've done the fuel pump cylinder but haven't lap yet
With some testing, I found a pump cylinder length of about 8 to 10 mm to be fine - because the plunger stroke is very small - about 1 mm, but I wanted the best I could so I made it almost 2 times longer.
The engine only needs 4 but I did 5 and I will choose the best 4 for the engine and the other 1 for the injector testing.
With this 4-cylinder engine, I try to equalize the amount of fuel for each engine cylinder so I have to make 4 cylinders of the fuel pump which must be of the same diameter.
20221121_170825.jpg


Although I have some experience with small diameters, But before I lapping , I need to redefine a few things, so I made several cylinders out of brass, steel and different lengths. for test

Cylinder and plunger for test

20221128_172001.jpg




lapping this small diameter cylinder probably only have 2 options: buy or make it yourself
Lapping it is a challenge
Must be remove all scratches caused by drilling or reaming and to ensure it is relatively straight throughout the lapping process.
With purchased or homemade tools, they only have 2 parts in contact with the cylinder - they actually don't make perfect contact with the cylinder and it can give a lot of shape to the cylinder - so lapping takes very careful and meticulous

20221128_175723.jpg
 

minh-thanh

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Hi All !
An update with few mistakes
20221129_174157.jpg
20221129_174528.jpg



I make some washers for the cylinders, they are made from mosquito spray bottles and soda cans

20221204_110249.jpg


And :

20221203_141901.jpg
 

minh-thanh

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What was your mistake ?

Scott

The first camshaft, the 3rd cam lobe got the wrong angle and a few other parts I had to redo
I should have chosen a 2 cylinder engine, with fewer cylinders less parts.... anyway complaining is pointless.
Must go on .
 

minh-thanh

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Hi All !
An update

I haven't finished the fuel pump yet, I will continue with it later.
Image of the crankshaft more than a month ago
20230110_113304.jpg



Because the stroke is too long and have time to learn more about the cause of the shaft fracture....
So I borrowed my brother's machine to do it - I did it very slowly, as carefully as possible, as well as reduce stress..when i machining it
And :
20230113_195338.jpg

20230113_195426.jpg



And camshaft :

Assembly1 TEST ALL 2.jpg



Camshaft 3.jpg
Camshaft.jpg



20230107_170620.jpg
 

minh-thanh

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Hi All !
An update
I drilled 4 holes for the fuel pump - They are really hard to locate and drill , with 1 hole drilled in the wrong place so I made another piece of aluminum and drilled it again , I drilled from drill bit 3 -> 3.5 -> 4 and finally 5mm and make thread 6x1 mm
20230126_091728.jpg

20230126_091520.jpg


I have to make an extra shaft similar to the crankshaft and camshaft to locate......

20230126_091326.jpg



20230126_091211.jpg
20230126_091223.jpg
 

peterl95124

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Minh, thanks for sharing, I've never soldered bearing halves together either, I just put the two pieces in a 4-jaw chuck and machine away. if the parts stick out beyond the chuck and I'm worried about a drill bending the halves apart (happens with crappy bronze, AKA gunmetal) then a collar with a setscrew will hold them together or a lathe dog or any sort of makeshift clamp.
 

minh-thanh

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Hi Peter !

When I process it I usually do it in order
EX : If there is ID 10mm and OD 12mm
1- drill holes 3 or 3.5 mm
2- drill hole 6
3 - drill holes 8 and drill holes 9 mm
4 - Turning outside diameter approx. 13 or 13.5mm
5- Turn inside diameter up to 9.8 or 9.9 mm
6- Turn the outside diameter to the final size
7- The final step is to reaming or lapping the ID to a size fit for the shaft
If the ID has a suitable diameter for ID turning, then I drill 3 or 3.5 mm and then turn to a 9mm hole and do the rest of the steps.
Sharp drills and sharp turning tools .
 

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