There are many kinds of Farmall tractors with several different engine types requiring specific torque settings. In terms of engine servicing, torque refers to the amount of force needed to tighten a component. This is important information to have, to ensure that an engine is maintained to recommended specifications. Specifications are usually given in foot-pounds.
The cylinder head, sometimes simply referred to as the head, sits on top of the cylinder block and is usually clamped with studs or nuts. The nuts need to be equally tightened to prevent leakage or overstraining. A flathead engine has a flat plate of metal bolted to the top of the cylinder bank. According to Weber's Tractor Works, for Super A tractors with C-113 gas engines, C-113 distributor engines, C-123 gas fire crater piston engines and C-123 distributor flat top piston engines, the torque wrench setting for the cylinder head is 80 foot-lbs.
The engine's intake or inlet manifold delivers the fuel/air mixture to the cylinders. For Super A tractors with C-113 gas engines, C-113 distributor engines, C-123 gas fire crater piston engines and C-123 distributor flat top piston engines, the torque wrench setting for the manifold, as recommended by Weber's Tractor Works, is 20 foot-lbs.
According to the International Harvester I&T Shop Service Manual IH-8, the torque wrench setting for rod nuts locked with a cottar pin is 40 to 45 foot-lbs. A cottar pin is a pin, or in some cases a wedge, that passes through a hole so as to affix parts together tightly. For self-locking rod nuts, the torque wrench setting is 43 to 49 foot-lbs.
The torque wrench setting for the main bearings should be 75 foot-lbs. The main bearings are those on which the crankshaft rotates.