Seetz, your summary steps to changing the piston are correct in principle, but simple steps have a way of becoming complicated. First, what engine do you have? Are the pistons aluminum? If this is a 216 or early 235 engine, the connecting rods bearings are babbited and will likely have shims under the caps. Pay attention to the shim stacks and return them to the same place. Also, if this is what you have, make sure you put the dipper on correctly- facing the oil spout in the pan- or toward the cam shaft. If you have a 235 with insert bearings, there may also be a shim under the bearing shell. If there is, make sure it stays where it is when you assemble the rod. I don't remember with any certainty, but the wrist pin may be pressed into the piston, or it may be held by a clamp bolt at the small end of the connecting rod. The early engines had the clamp bolt, but I don't recall on the later engines. With the clamp bolt, the wrist pin floats in the piston, so make sure the pin is centered in the piston and won't extend beyond the piston diameter when you move the rod the full extent of its side play, about 1/16 inch either way. If you have aluminum pistons, there may be a notch that indicates the front of the piston. Don't put it backwards on the rod and in the cylinder. If you have the clamp bolt on the rod, I believe that bolt should face the cam shaft when the assembly is installed in the engine, and the piston should be installed with the notch to the front of the engine. Check the other rods and pistons before you take everything apart. I don't think the cast iron pistons have a 'front' position. Determining the cause of the puncture is of high importance. Detonation is the primary cause of that condition, so make sure you have the correct initial timing and correct timing advance in the distributor. From your description of towing the trailer, you may have had the truck overloaded, and that was the cause of your trouble. Although, if the power piston in your carburetor was working properly and the timing advance mechanisms were working correctly, you shouldn't have had any that trouble. But overheating certainly would be a factor, which may have been the result of overloading the truck and driving at a low speed with that load. Driving with a 3-speed transmission in the top gear, at low engine speed with a heavy load would certainly promote overheating. Check the condition of all the spark plugs. If they are very clean and white, that would indicate a lean fuel mixture, which would also contribute to overheating and detonation.
You may also have to buy a set of rings for the new piston. In principle, you could use the old rings, but you may break them, or bend the rails if you are not careful when removing them from the old piston. If you have to buy a whole set of rings, you might as well re-ring all the pistons. And lightly honing the cylinders, glaze-breaking, is customary practice. Also, you may have to remove a ridge at the top of the cylinder before removing the piston. Don't try to remove the old piston if the ridge is more than barely detectable.
Hope this helps.
Harvester
