Select a part to view solution for common problems associated with the item.

Operation: The crankshaft uses connecting rod journals that are offset from center line to convert the up and down motion of the pistons into the rotational force that drives the transmission. Advice: The main bearing caps that hold the crankshaft in place are not interchangeable. Ensure that they are returned to their original position and orientation when reinstalling the crankshaft. When removing or installing the crankshaft, use care not to nick or otherwise score the bearing surfaces. When reinstalling the crankshaft coat both main bearing halves and the bearing surfaces on the crankshaft liberally with engine pre-lube, often referred to as snake oil. Recommendations: Engine pre-lube (snake oil)

Operation: The main bearings support the crankshaft in the engine block. They are made of a softer material than the crankshaft, so that any normal wear happens to the bearing and not the crankshaft. Advice: Bearing thickness can be measured using plastigage. Follow the directions on the packaging. When disassembling, lay the bearings out in order so that you can inspect them for abnormal wear patterns. When reinstalling the crankshaft coat both main bearing halves and the bearing surfaces on the crankshaft liberally with engine pre-lube, often referred to as snake oil. Recommendations: Plastigage Engine pre-lube (snake oil)

Operation: The connecting rod connects the piston to the crankshaft. It's pivoting movement facilitates the conversion of the up and down motion of the pistons to the rotational force of the crankshaft. Advice: Bearing thickness can be measured using plastigage. Follow the directions on the packaging. The rod bearing caps that hold the connecting rods to the crankshaft are not interchangeable. Ensure that they are returned to their original position and orientation when reinstalling the pistons. When removing or installing the connecting rods, use care not to nick or otherwise score the bearing surfaces. When reinstalling the connecting rods coat both rod bearing halves and the bearing surfaces on the crankshaft liberally with engine pre-lube, often referred to as snake oil. Recommendations: Plastigage Engine pre-lube (snake oil)

Operation: The rod bearings allow the connecting rods to rotate on the crankshaft. They are made of a softer material than the crankshaft, so that any normal wear happens to the bearing and not the crankshaft. Advice: Bearing thickness can be measured using plastigage. Follow the directions on the packaging. When disassembling, lay the bearings out in order so that you can inspect them for abnormal wear patterns. When reinstalling the pistons coat both rod bearing halves and the bearing surfaces on the crankshaft liberally with engine pre-lube, often referred to as snake oil. Recommendations: Plastigage Engine pre-lube (snake oil)

Operation: When the spark plug fires, the air fuel mixture in the combustion chamber explodes, forcing the piston to move downward in its cylinder. It is this downward motion that turns the crankshaft and creates engine power. In a simple two cylinder engine, the downward stroke of one piston, forces the other one back up again in an endless cycle while the engine is running. Theoretically the more pistons that an engine has, the more of a push can be made on the crankshaft and therefore more power can be developed. Advice: When disassembling, if the pistons and connecting rods are to be reused, there is no need to disconnect them from each other, but note where each one came from so that it can be returned to the same cylinder when reassembling. Most pistons are designed to fit in the cylinder with a certain orientation. Check the repair guides for the engine you are working on. Use a proper size ring compressor and a soft rubber mallet when installing the pistons. Recommendations: Repair guides Rubber Mallet Ring compressor

Operation: The piston rings seal the small gap between the piston and the cylinder wall. Advice: Proper placement of the rings and orientation of the ring gap are important to the effectiveness of the rings. Check the repair guides for the vehicle that you are working on. Use care not to spread the ring gap too far during installation, doing so could break the new ring. Recommendations: Repair guides

Operation: The camshaft is responsible for controlling the opening and closing of the intake and exhaust valves. Advice: Use care not to nick or otherwise damage the bearing and cam lobe surfaces when removing or installing the camshaft. Before installing the camshaft coat all bearing and cam lobe surfaces liberally with engine pre-lube, often referred to as snake oil. Whenever a camshaft is replaced, new lifters or cam followers should also be installed. The wear pattern on the old lifters will cause premature wear on the new camshaft. Recommendations: Engine pre-lube (snake oil) New lifters with a new camshaft.

Operation: The lifter or cam follower, depending on engine design, is located between the lobe of the camshaft and the rocker arm or valve assembly. It's job is to maintain zero valve clearance or "lash" either mechanically via a valve lash adjustment or hydraulically using oil pressure to expand and take up any slack in the valve train. By maintaining zero valve lash, all of the pieces of the valve train can move as one without any rattling going on between them. Advice: Many older engines used solid lifters that required periodic valve lash adjustment. Most of today's engines use hydraulic lifters or cam followers. Before installing the hydraulic type lifters, it is a good idea to prime them with oil. To do this, submerge them one at a time in a container of fresh oil and while submerged use a pushrod to depress the plunger in the end of the lifter several times. This will introduce oil into the lifter and reduce the amount of valve clatter that happens on initial engine startup. Lifters are designed to spin while riding on the camshaft. This spinning motion helps to distribute the load evenly across the lifter while wearing the camshaft lobe primarily in the center. Because of this unique wear pattern it is advised to replace all of the lifters whenever the camshaft is replaced. Likewise if a lifter must be replaced you should replace them all along with a new camshaft. Regardless of which type of lifter being used, a generous coating of engine pre-lube, often referred to as snake oil, should be applied before final installation. Recommendations: New lifters installed with new camshaft or vise versa. Engine pre-lube (snake oil)

Operation: The rocker arms transmit the movement of the camshaft lobes, lifters and pushrods to the valves. As the rocker arm moves it pushes on the valve stem opening the valve. Advice: If the rocker arms are to be reused, ensure that they are returned to their original position and orientation when reinstalling. Before installation, coat all friction points with engine pre-lube, often referred to as snake oil. Recommendations: Engine pre-lube (snake oil)

Operation: The valve springs are responsible for closing the valves and holding the valves in the closed position. The movement of the rocker arm on the valve stem overcomes the tension of the valve spring to open the valve. Advice: If you are sending the cylinder head to the machine shop for service, leave the valves and valve springs installed. The machine shop will need them in place for pressure testing.

Operation: The intake valves are responsible for opening and closing the passages that let air/fuel mixture into the combustion chamber. The exhaust valves are responsible for opening and closing the passages that let exhaust gases out of the combustion chamber. Advice: If you are sending the cylinder head to the machine shop for service, leave the valves and valve springs installed. The machine shop will need them in place for pressure testing.

Operation: An engine gasket kit contains all of the necessary gaskets for rebuilding the engine. In many cases there will be more than one choice of certain gaskets so that the kit can cover as many applications as possible. Be careful which one of the available choices you use. Advice: Before installing any new gaskets it is very important to compare the new gaskets with the old ones. All passages must align correctly for proper sealing. Some gaskets will have arrows or text detailing the way that they should be installed. When the intake and exhaust manifolds are located on the same side of the head, they often share a gasket, or their gaskets are joined together to ease the assembly process. This style of intake/exhaust manifold setup will usually have several bolts that pull down on both manifolds at the same time. These bolts will often have a large flat or convex washer to distribute the load evenly across both manifolds. Ensure that these washers are properly in place and not cocked to one side before tightening the bolts. Always tighten the bolts to specifications in small increments following the correct tightening sequence found in the repair guides. Recommendations: Repair guides