Apr 17, 2020
This is the 16th post in our ongoing series on Project Super C. We are chronicling the rehabilitation of our 1954 Farmall Super C tractor, which has taken up residence outside of the Farmers Business Network℠ office in San Carlos. If you are new to this series, please start with the introduction to the project in our first post.
In our previous post we removed all of the external components from the front of the engine in preparation for removing the crankcase front cover and then the internal engine components. Our objective this time is to remove the crankshaft. Once we have done that, we should be able to remove the pistons.
We started by unbolting the front cover. Note that at this point we had the engine turned upside down.
This exposed the timing gear train: the camshaft gear (large, center), crankshaft gear (top left), and governor gear (lower right):
Before we did anything else, we marked the relative positions of the three gears. When we reinstall them it will be important to put them back in the same way. This is because they coordinate the timing of the piston positions, the valves opening and closing, and the firing of the spark plugs. If the gears are installed in the wrong position, the timing sequence will be wrong and the engine will not work.
As we looked more closely at the newly exposed parts of the engine, we found a new surprise. Significant welding has occurred on both the left and right sides of the engine where the front chassis bolts to the engine. The pictures below show the welds on the inside and outside of the right side of the engine. There are similar welds on the left side.
It is pretty clear that the engine block was fractured at these points and then welded back together! We have a good theory as to how this damage occurred. If you read our post about removing the engine, you may recall that the Super C’s engine serves as a structural component. We believe that the tractor was in a front end collision and as a structural component, the engine received the force of the collision, breaking it at these connection points. This accident theory may also explain one of our earlier mysteries. We suspect that one of the rear axles was replaced at some point - perhaps it was due to damage from the same accident.
The discovery of the welds in the engine definitely does answer one question for us—in our last post we wondered why the fan drive pulley had been removed in the past. At a minimum, this would have been required in order to perform the welding inside the engine.
We moved on to unbolting and removing the oil pump. It looked pretty sludgy, and will at very least need to be thoroughly cleaned. We set it aside and will tackle that project at another time.
With the oil pump out of the way, the crankshaft was fully exposed. The job of the crankshaft is to translate the linear motion of the pistons (triggered by exploding the gas and air mixture) into rotational motion, which is eventually conveyed to the rear wheels.
To remove the crankshaft, we needed to unbolt the front and rear seals, the crankshaft bearing caps, and the connecting rods (which connect the pistons to the crankshaft). Normally this is a straightforward matter of removing some nuts. However, because our pistons are stuck in their cylinders, and the pistons are attached to the crankshaft, the crankshaft could not rotate. This left four of the connecting rod nuts that we needed to remove in hard-to-access positions, and without being able to turn the crankshaft we could not rotate them into more accessible locations. A picture will make this clearer (connecting rod nuts are noted in yellow and crankshaft bearing cap nuts are in red):
The two connecting rod nuts (in yellow) at the top of the picture and the two at the bottom were angled toward the side of the engine and we could not easily get a socket wrench or ratchet onto them. After a lot of contortions and tool improvisations, we did eventually get them off. This allowed us to lift out the crankshaft:
Below you can see the engine with the crankshaft removed. The four connecting rod bearings and the three main bearings which had been mated with the seven crankshaft journals are called out.
In a later post we will assess the bearings and decide whether they need to be replaced. First though, we are going to attempt to remove the pistons! Join us in the next post to find out how it goes.
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Apr 17, 2020