Ferguson TEF head rebuild

The Standard Motor Company 20C engine found in the Ferguson TEF20 was the first diesel engine fitted en masse to Ferguson tractors, after Harry Ferguson, the pioneer of the Ferguson Tractor thought diesel engines were noisy and crude.

Pressure from competitors tractors such as the Fordson Major, which was not only more powerful than its petrol counterparts, but also more economical twisted Ferguson’s arm into fitting diesel engines into the TE20 line of tractors.

A number of farmers were ahead of the trend on this, and fitted Perkins P3 engines into their Ferguson TE20 tractors, replacing the original fitted petrol engines.

The rather crude looking P3 conversion of a TE20 tractor – The Perkins P3 was known for its easy starting and reliability.

The 20C engine fitted to my 1954 TEF20 was the original engine, and had seen better days. It was breathing heavily out of the breather pipe, suggesting cracked/worn piston rings or glazed liners. I was keen to do a full rebuild so wasn’t worried by this, although it was to be my first full engine rebuild.

I started by stripping the front end such as radiator & hoses, dynamo etc, and then removing the inlet and exhaust manifolds to leave me with room to work.

Ferguson TEF20 standard motor company 20c engine
The stripped engine block with manifolds and front end removed – Just the decompression assembly to take off after this picture.

I then stripped off all the injector pipes and injectors from the other side so I could remove the head.

Ferguson TEF20 head removal
Complete with a bit of tinfoil on the injector pump to stop and rubbish getting in – I clearly cared far too much at this point!

You can tell a lot about the state of an engine by looking under the rocker cover and inspecting the head/valve gear. Thick sludgy oil, or large carbon buildups can be a sign of problems in the engine.

On the whole, I was very happy with the condition of my valve gear, it was relatively clean for the age of the tractor and all in good condition.

In the picture above you can see that I’ve already removed all the nuts holding the head on – These can be undone in any order but must be done up in sequence – I’ll include the diagram for this in a future post.

Getting the head off was quite a challenge being on my own, I didn’t have anything to lift it off, and it took some wrestling up and over the studs as I wasn’t tall enough to lift it properly – I ended up standing on the front axle and lifting it, which was fine until I had to get down with it!

Once the head was off, I was able to strip the valves out using a borrowed valve spring compressor – using this avoids firing the collets across the garage!

The valves all in all weren’t in bad shape – Just high carbon buildup around the valve shaft, but no heavy pitting or damage.

How to remove Ferguson TEF20 valve springs
You can see in this picture the heavy carbon buildup, but the relatively good condition on the valve seat face.

After cleaning up all the valves and the head itself, I lapped in the valves with course then fine grinding paste and put the valves, springs and collets back in to complete the head ready to go back on. You can find a link to the valve grinding kit I bought from Amazon below

After all that, the head looked like this – Ready to go back on when the bottom end had been rebuilt.

Ferguson TEF20 head rebuild with valve lapping
The finished article – Head strip down and rebuild complete.