The white metal coating on the phosphor bronze bearing showed some slight wear, but when assembled on the journal there was only the tinniest amount of actual play which was all down to clearance, so I left this as it was.
Lubrication is by the oil being forced into a pickup pipe projecting out of the underside of the bottom cap. As the crank rotates this pick up pipe dips into the oil bath of the sump. The oil is then forced up the pipe by the inertia and into the lower bearing shell. The oil hole can be seen near the top in the middle, where it has had a channel cut into the bearing for the oil to circulate around to the top half.
The rear lobe nearest the gear wheel, is the cam for the valve operation, while the lower front one just operates the fuel pump. This front lobe showed some sign of wear, but as it only operates the pump this was of no real concern.
This lobe is also adjustable, so you can alter its position on the shaft to set the pump timing. This is only meant as a very coarse adjustment, as there is a fine adjustment knob on the back of the housing you can use (see 11a).
When you undo the nut, that you can see bottom right, it automatically pulls the lobe off of a taper on the shaft, allowing you to swivel and reposition it, before you retighten the nut once again to lock it in place.
I did not realise this when I undone the nut initially, and therefore lost the original position. I later managed to time things by using the 'spill point' method and the flywheel marks, once the engine was finished.
Unfortunately this nut needs to be undone before you can remove the shaft, or detach the housing away from the block, so marking with paint is advisable beforehand. The large gear wheel of the camshaft is removed from inside the engine (a single very tight nut with a spring washer) and then you undo the nut mentioned above, to pull the pump's lobe off of its taper. The shaft, for which I made a new thrust washer can then be passed through into the main engine block and lifted out. After that just three studs hold the housing to the block (two form part of the cover and are long studs, plus a shorter stud inside the housing - see 7A).
A simple but effective seal for the cylinder head is provided by a thin copper ring that sits in the recess in the head. After annealing I simply re-used the existing copper ring.
There was naturally a wear lip at the top of the bore, but for the age of the engine it was perfectly acceptable, and was in excellent condition for a 64 year old engine. There was no pitting or gouges at all, and so it was only honed to remove the glaze. As there were no oversize marks on the piston, I assume it could well be the original bore.
The four copper tubes that you can see (circled), are for allowing the flow of water from the head down to the block. They each had rubber seals around their ends which were the equivalent of modern type O rings. These then located in their respective recess in the top of the block (see 4 above - circled), and when they are compressed they seal themselves to stop any water from leaking out.
The idea actually works quiet well, and saves having a complicated head gasket. I found that a modern O-ring in rubber could not be found for the correct size, so I bought some 5mm diameter Viton O Ring Cord and made my own, joining the ends with super-glue.
The O ring needed to be very carefully sized, otherwise it is too big to compress fully, making the head refitting difficult to impossible, (as I found out the first time).
The other five holes you see are for the long cylinder head studs. In the absence of any figures I torqued these to 100 Foot/pounds.
The inlet cage is held in place by four studs, but the cage can be a tricky little thing to extract outwards from its housing. The thin copper washer that you can see, acts as a gasket on the seating deep in the head (arrowed). This obviously needs to be annealed before re-use.
Valve grinding was done as per standard procedure, but the exhaust valve sitting deep in the head, and only accessible via the inlet housing shown, can be rather fiddley. Fortunately the valves have a slot machined into their heads for a wide screw driver to locate in, which you can then use to twist them back and forth for the lapping in process. A much easier method than using a rubber cap on a wooden stick to grind the valves!
The projection on the right hand side with a curved end is the water outlet, and is shaped to seat against the tank. Bamford rather confusingly call this method, whereby the tank is bolted directly to the engine, "hopper cooling".
This can be very confusing when you compare against a hopper cooled Lister or Wolseley for example, as Bamford's idea of a hopper is in reality just an external tank.
A Bamford 'tank cooled' engine is conventional though, and resembles that of a Lister, whereby the tank often sits on an elevated box alongside.
The two long studs also help hold the exterior cover in place.
The engine came with its original water and fuel tank. The water tank however will need a new bottom as that part is quiet rusted. The rest of the tank is still quiet usable, so I will be able to utilise it. The unusual fuel tanks that these engines have are circular, but with a large hole in the middle slightly larger than the water tank's diameter, much like a giant Polo mint. The fuel tank then sits around the water tank at the tank's top.
This can be seen better in photograph 18 (positioned at the rear).
These both proved extremely time consuming and difficult to remove. The timing side had a large cast iron flat belt pulley that needed to be removed first of all. However it just refused to budge, despite various pullers, soaking in diesel for several weeks, penetrating fluid, and copious amounts of heat. So I eventually decided to reluctantly cut the pulley off with a large angle-grinder.
This was done by slitting across the pulley in line with the crankshaft. I then drove in several steel wedges and caused the cast iron boss area to crack around the crankshaft. I do not like to destroy things like this, but sometimes it can be the only way forward.
I next applied a homemade puller that used a 10 ton bottle jack to the flywheel, which I eventually managed to remove.
The flywheel on the other side proved even more difficult however, and although I got the gib key out, that was as far as I managed to get.
I therefore decided to leave this flywheel attached, which made work extremely difficult due to the associated weight.
When the engine was finished and I gave it its first run, I had forgotten that I had not replaced the gib key of the stubborn flywheel and it then came loose of its own accord, moving on the crankshaft.
Obviously the inertia given by the engine firing was enough to break the rust seal, where other methods had failed. I have heard of people using this method intentionally, and although extreme, it does appear to work.
IF it had come off the end of the crankshaft however, the consequences would have been far different.
The large cog wheel has been replaced for this picture, and would normally have been removed from inside the engine, allowing the pump housing to be pulled away from the outside.
Here we have the cover removed and you can see the end of the shaft as mentioned in paragraph 2 above.
Although the fuel pump sits immediately above the cam that operates it, it does in fact operate by way of an intermediate lever that sits in the middle (shown in orange). The right hand end of this lever pivots on an eccentrically mounted cam (dark blue) that is fitted off centre on the light blue shaft. By rotating this light blue shaft's position you cause the operating lever to move its position on the operating cam's lobe, and thus alter the moment of injection.
You can in fact even do this while the engine is running.
There is a small bolt in the top of the housing that bears down onto the shaft and normally locks it in position to stop movement.
On my engine this was very badly worn and would have caused the timing point to be erratic, so I made another eccentric cam and also bushed the operating lever.
The internal parts are shown in the upper white box. The plunger part that is operated by the fuel cam is retained by a circlip, and can prove difficult to remove once the circlip has been taken away. Mine had become gummed up and I had to soak it in diesel for a few weeks and then apply some moderate heat to the pump body. I then banged the whole pump body down onto a hard surface, and slowly, very slowly in fact, the plunger started to come out. This sounds brutal, but I was advised on the Stationary Engine Forum that this is the normal method of removal.
All the components are very delicate so nothing should be forced at any time. Fortunately there was no damage from water getting into the pump element and body.
See Peter Forbe's comprehensive site for detailed information.
The external cap 'A' unscrews to reveal part B underneath which screws down onto the spring 'C'. Care must be taken here to count how many turns things are unscrewed otherwise you will affect the pressure that the injector operates at.
Great care needs to be taken with these parts to avoid dirt or water getting in contact with them.
The injector itself sits in the middle between the valves and is of the Pintle variety, which means it has the very tip sticking out of the end of the injector, so care is needed when placing it down on a bench.
The engine uses direct injection into the top of the cylinder head, where there is a recess with the valves positioned either side.
These came out fairly easy by almost packing out the space between each gib key's head and their flywheel boss with a piece of old flat metal bar, and then driving the wedge shaped blade of big steel chisel into the remaining space, forcing the key outwards.
The main bearings initially looked disappointing as they appeared to show some minor cracking and wear, yet in fact there was minimal lift on either flywheel (4 thou and 3 thou) when assembled. Because of this I had considered replacement, but the areas affected, bar one patch, refused to lift, so I decided they were still usable. A tiny portion had come away, so for this area as it was so small in relation to the bearing surface, I used a trick I read about on the Smokestack forum, where very small areas can be filled with a liquid metal. Once cleaned with an industrial de-greaser (Dichloromethane) I treated the less than 0.25 inch square area.
Sounds an easy solution but getting the surface to the same level as the surrounding white-metal afterwards is pretty tedious.
I checked the bearing several months later and all seemed well, the repair just showing as a darker area in the white metal surface.
If I ever decide to put the engine to some real work one day, rather than just rally it, they will be worth white metaling again. Something I have not done before, but is not too diffucult.
After assembly and checking the lift with a dial gauge, I decided that the original shims (three each side )should be left in place, so after cleaning and some gentle polishing to the crank journals, I was happy.
These are substantial, being quiet a large physical size with a large bearing area, and consist mostly of bronze, with a white metal coating of about an 1/8 inch thick. These have oil way paths cut into them the same as the big end bearing has.
The piston has grooves for four compression rings but mine came with just the three rings shown fitted, the lower compression ring being empty, presumably missing or broken at some stage. Compression on the engine is still very good however, with it being extremely hard to turn it over manually against the compression when cold, and nigh on impossible when hot. I may replace the missing ring however, but it's not urgent as it is not affecting compression or running.
The throttle linkage (far right) has holes either end where pins swivel, and these were consequently quite worn. As this wear had quite an impact on throttle response to any movement from the governor, I decided to make another throttle linkage. .
Lubrication of the rocker arms on their spindles is by oil can before running. On top of the cylinder head are two brass oilers and these feed down into channels machined lengthwise into the top of the rocker arms. The bottom of these channels being open to the spindles they run on. A rather crude affair, but I found I had very little wear at all on the rockers or their spindles, so it must be very effective.
The exhaust valve guide even has its own wick oiler, whereas the inlet valve guide relies on oil mist. Both the valve guides in the cylinder head were in excellent condition thankfully.
The engine as I bought it. The previous owner had got the engine for restoration but time and other projects meant it was not to be. Originally the engine was supplied in June 1947 to Fenning's of Stockbridge, Hampshire UK. Sixty-three years later I found it thirty odd miles away from that original location.
A very substantial casting giving six inches of stroke on the SD3
These are 24 inch diameter. Later models had the less appealing solid flywheels, with cut-outs in them.
One of the governor's two centrifugal weights can be seen here (circled in red). These are normally attached to a ring that is bolted to the boss of the flywheel. They in turn move the sliding sleeve (arrowed blue) which has a roller on a bearing that bears against the sloping edge, seen at the tip of the blue arrow. This causes the throttle arm to swing as it rises up the ramp of the slope.
The roller bearing was badly worn, so this was replaced.
The 4.5 inch diameter piston is cast iron and quite heavy. I have a suspicion that this may not be original as there was very little wear, if any, in the ring grooves themselves. I have heard of diesels often needing thicker rings on older engines, but thankfully this piston was excellent in that respect.
The gudgeon pin though, despite being a harder material, was very badly worn, yet the piston holes were not.
This too had too much free play, so I made a replacement gudgeon pin using Stubb's silver steel. When used for gudgeon pins, it is usual to leave it in it's unhardened state, to avoid it becoming brittle. The piston holes and the small end were then bushed with some SAE 660 leaded bronze that I turned up.
Looking up into the engine block they can be glimpsed at the top. The hole underneath is where the pump housing and camshaft would normally project through, allowing the followers to contact the cam lobe. The followers showed some slight wear and were lightly reground and polished in places, with a thrust washer added.
My flywheels were quiet badly corroded and I had trouble finding the timing marks. The engine has the following marks:
| EC | = Exhaust Closes |
| TDC | = Top Dead Centre |
| Fire | = Injection Point |
| IO | = Inlet Opens |
On the side of the block on the pump side is a vertical line in the casting. This is used to align the timing marks too.
If the keyway is at the 6 'o'clock position the piston will be at TDC, so the very top of the flywheel, where it aligns with the line in the casting, should now be the TDC point. So if you have a 24 inch flywheel (SD3 and SD4) draw 4 lines on a piece of paper laid flat as shown below, and then lay this onto the curved surface of the flywheel. You will then get the position of the missing timing marks.
(The measurements were taken from my own 24 inch flywheel)
(August 2011 video - updated one now available, see link below)
***** Update 18/02/2012 *****
Now for Sale on Ebay, Item number: 260960640752
See also new YouTube Video