Kubota diesel KND3

Dear forum members,

I've bought a new motor recently.
It's a single cilinder Kubota KND3 horizontal diesel engine.
Runs like a watch and needs a bit of TLC and a new trolley.
Seems a good project for the coming winter.



Don't know if it was a common engine in UK?

Best regards,

Steef

Hi there . I had a KND same as yours , I sold it and wish I never , they are lovely runners, the colour is a bit pants but they run and start superbly , nice find

Jon

Dear forummembers,

After the show in Tilligte where an oil problem occurred I've rechanged the oil.
When the engine was turned by hand the oil indicator didn't move upwards.
Even with a very short run it seems there was no oil pressure.

Therefore I've decided to strip the engine and have a closer look at the problem.
First action was to remove the flywheel to enter the oilpump.
After a week soaking in WD40 and penetrating oil the first attempt was done to remove the big nut.
I could use a big spanner from a local Mercedes truck dealer.
A few attempts later the nut came off without damage


To pull the flywheel off I've made a spanner from an old piece of oak and three threaded rods M10.
I've sprayed penetrating oil in the shaft and key hole for a few days.

Then I did a first attempt. Was a little bit nervous that the tension caused by the threaded rods could crack the flywheel.
Luckily the flywheel came off after a little help with a heavy piece of wood

The cover plate of the oilpump was removed. The rotor from the pump didn't turn when I (carefully) cranked the engine.
After removing the oilpump rotor it seems that the shaft which fit in the camshaft is too short.


(Oilpump already removed on the pictures)
See the damage in the central bore; hope this can be repaired
Still have to remove the camshaft to check if the remaining part of the shaft is stucked in there.
Therefore the left side (fuelpump cover) has to be dismantled as well.
I hope that the nut in the camshaft is not worn out. Praying for the best.

Keep you updated.

Best regards,

Steef

Dear forum members,

Today I've removed the side cover of the engine to take a closer look at the oilpump connection in the camshaft.
First I had to clean a severe layer of old oil and grease from the bearing and the cover.

In the centre of the camshaft there is a circular shape; seems it's worn out.



Still thinking about the best option to solve the issue.
Don't know if it's possible to weld on a layer of wear resistant material
Guess the camshaft should be (surface) hardened; risk of cracks
Didn't see any (second hand) camshaft on internet up till now.

Any suggestions or ideas?
Please let me know.

Best regards,

Steef Pronk

Not a DIY job but metal spraying might be the answer, followed by a trip to a skilled machinist. Might be expensive

Dear forum members,

Been a while since the latest update.
Decided to strip the complete engine and give it a good internal cleaning.
This gives the opportunity to take a closer look at the current state of some critical parts.

A thorough cleaning of the inside was absolutely necessary.
All parts were covered with a thick layer of sticky black sludge.
The usage of brake cleaner and Dasty increased to a high level last weeks

Luckily there were some marks on the camshaft and crankshaft visible to determine the correct timing.
Got pictures from a partsbook which will help me with the (future) assembly.





Found issues sofar

- bigend bearing worn out (copper surface visible on some spots)
- piston pin bearing worn out ( abot 0,1mm play; guess this was the reason of the ticking sound while slowly crancking the engine)
- oil pump malfunction
- cilinder bushing surface no hohne pattern visible. Ridge on the bottom of the cilinder

Have to measure the crankshaft to determine if regrinding is possible.
Keep you posted

Best regards,

Steef Pronk

Dear Forum members,

Found some sparetime to continue the work on the engine.

Removed the oil seal ring from the RH cover and the conical roller bearings from the camshaft.
Conical bearing rings were removed in an earlier stage. (See the casette at the leftside of the camshaft in the picture below.) 



The type of roller bearing number is 30307.
Found SKF bearings on a webshop for a reasonable price.

Conrod bearing is worn out and piston pin bearing as well.


A local overhauling company will make a new piston pin bushing and will press it into the conrod.
To search for the conrod bearing continues.

Best regards,

Steef Pronk

After a very long time I've continued to work on the Kubota.
Meanwhile the engine is mounted back together.
Found a used camshaft with a suitable nut for the oil pump.
Company Kosfain Taiwan provided me several parts like the big end bearings and conrod bushing.
Engine has made a first testrun as well.
Oil pressure problem is solved.
Now I need to do cosmetic work

Gasket between watertank and engine finished
Started cosmetic work on the watertank and flywheel.

A lot of sanding and filling. Need to solve some small imperfections and then watertank and flywheel are ready for their final paint

Looks like your usual impeccable work Steef. I look forward to seeing the finished article.

Paul,
Thank you very much for your nice reply.
Really appreciate that and keeps me motivated.
Have applied the first layers of epoxy primer today.
Watertank needs minor detail work.

Today's pictures.
A lot of sanding - filling - sanding.
Step by step I'm getting there
In an earlier stage I've made some tests to get the right color.
Unfortunately the color scan made by my local paintshop did not meet my expectations. (Looked like the red color of a very old Ford Fiesta)
I've seen pictures on internet from Kubota engines with a blue / grey color scheme.
Maybe a good alternative as the salmon color is quite odd.

The weather conditions were very good today.
Used the sunny afternoon to spray the engine block in the epoxy primer.
I've used Spraymax 1K epoxy spraycans. The nozzle can be turned to spray horizontal or vertical. Excellent solution for tricky spots.
See pictures from today,

Flywheel and left side of the tank need some minor filling.
Then the top coat will be sprayed.

Looking great, with that level of preparation the finished job will be worth waiting for.

New colors

Painted the engine block and some components in the new color.
See the pictures below.
Tank and watertank will be done tomorrow.

Dear forum members,

Today I've finished the paint work on the fueltank and watertank.
See attached the pictures.
Realizing that the fuel tank needs to be adjusted to be more in line with the watertank.
Hope you like the new colors.

Wish you all a nice weekend.

Such a stickler for precision Steef! Looks good.

Paul,

Thanks again for your positive feedback.
Started to build up the engine.
Need some small bits en pieces but not that much.
See the pictures from this morning

After filling diesel and bleeding the system the KND3 is alive again
Oil pressure is visible on the indicator

After filling diesel and bleeding the system the KND3 is alive again
Oil pressure is visible on the indicator

Looks great, lots of time went into the complete job and the outcome is excellent, what hp is that engine, great runner.
Well done, a restoration project is not a race, its takes time to complete it when we can.

Chris

Great job Steef.

Paul and Chris,

Thank you very much for your positive comments.
@Chris, this engine has 4HP at 2000RPM.

Realizing that almost four years have past since I've started this topic. Due to other priorities the restoration process was stopped at a certain point.
The current lock down period has given me the opportunity and motivation to continue the restoration.