Smoking diesel mystery

[zegersfarm]

I have saved a Zetor 7045 from a farm where it had been sitting outside for over 20 years. The hour meter shows 2122 hours. The engine was seized, which was expected.

I have replaced the cylinders and pistons and the valves, I have ground the valves/ seats.
The injection pump is tested and adjusted and the nozzles are new. This was done at a certified diesel shop.
The tractor starts but smokes heavily, white smoke, not consistently on 3 cylinders. Three of the four exhaust ports are wet, one port looks fine (the port not smoking). The compression test shows over 300 PSI at room temperature. A test with a different tester showed 232 PSI at 21* Fahrenheit.
I have switched injectors from one cylinder to another, and the smoking stays with the cylinder.
I have been trying to locate this problem for over a year now. It would be nice to use the tractor this spring for planting.
I have no idea what is causing the 3 cylinders not to ignite correctly.
Now I am thinking that the valve springs might have lost their strength. I discovered that I can push the valve down by pushing on the spring retainer cup with my hands. This seems odd.

What do you people think?

 

[Hay Dude]

Your intuition is probably correct. If the valve springs can be easily compressed, change them out and if nothing, it’ll check that box off as a possibility. Just weird that one cylinder doesn’t do it…

 

[bmaverick]

Are the valve springs in the head like most diesels?

If you take the head off to access the springs, verify the spring key characteristics of the good cylinder and then go shopping around for replacements.

This tractor brand is somewhat popular in Russia and other countries around there. Even the people that like the brand complain about their machine.

Valve springs are very very very important to the timing.

 

[zegersfarm]

Your intuition is probably correct. If the valve springs can be easily compressed, change them out and if nothing, it’ll check that box off as a possibility. Just weird that one cylinder doesn’t do it…

There was one cylinder in compression stroke for over 20 years. The springs were not compressed. That might be the difference. I didn't think they lose strength, many engines are older than this one, but who knows?

 

[California]

Any chance that is water vapor? You might run that exhaust onto paper then see if it is unburned fuel, or water.

 

[kenmac]

Cracked water jacket in the head, or block ?
You say the exhaust ports are wet. but you don't say if it's diesel, or water
Chance That white smoke could be steam ?

 

[zegersfarm]

Each cylinder has it's own head and head gasket, no cracks in the block. It has sticky soot in 3 exhaust ports. One exhaust port is dry soot.

 

[Tx Jim]

Have you got engine up to operating temp & tried putting it to work pulling a plow or on dynamometer? Did you utilize break-in or regular diesel engine oil?

 

[dodge man]

Lots of possibilities but I agree, you shouldn’t be able to compress springs by hand unless you are really strong.

 

[zegersfarm]

I put the disk on it for one hour and worked it hard. The engine oil is regular Rotella 20W30 for diesel.