Beating- the amplitude of the deviation of the shaft tail from the axis.
Insert - a part of a bushing placed in a cylinder as a friction bearing surface for a shaft, piston pin, etc. As a rule, liners are replaceable parts.
Surface development - the presence of scratches or grooves on the surface. The cylinder wall may become worn due to the presence of abrasive particles that are moved up and down by the piston rings.
Bearing protrusion - excess height of the liners, due to the presence of which a tight fit of the back side of the bearing to the bed is ensured after engine assembly.
Gas distribution mechanism - the engine valve mechanism, which includes parts from the camshaft to the valves.
Tumbling- removing burrs from the working surfaces of the bearing.
Sleeve- replaceable bushing pressed into the engine block. The inner surface of the sleeve is the cylinder wall.
Damper- a cylindrical counterweight located in front of the crankshaft. The damper is a damper of torsional vibrations of the shaft caused by the action of the pistons.
Detonation- a process that occurs when there is a misalignment between the ignition phases and valve timing and is manifested by a metallic knock.
Iron azure - a blue pigment that is used to determine the contact area of elements. Used to determine the width and location of the valve head contact with the seat.
Plug- a soft metal plug that is installed in the hole of the engine cooling jacket.
Bullies- a type of wear caused by the movement of material of rubbing parts. Appears as small pits or grooves on the surface.
Gap- the space between two elements. Sometimes defined as the distance a pinion can move without moving the gear with which it meshes.
Gap- the distance between parts of one group, for example, between the teeth of a gear transmission or between a pusher and a valve stem.
Rounding- transverse or inclined bevel of the sharp edge of a part
Replacing rings - a procedure that includes replacing piston rings and treating cylinder walls.
Cylinder mirror - extremely smooth cylinder wall surface.
Combustion chamber - the space between the piston at TDC and the inner surface of the cylinder head, where combustion of the fuel-air mixture occurs.
Piston groove - a groove in the piston head where the ring enters.
Major repairs - a comprehensive event that includes disassembling the unit, cleaning and inspecting its parts, necessary replacement or restoration of elements, assembly of the entire unit and adjustment.
Carter- the lower part of the engine in which the crankshaft is installed. The crankcase includes the lower part of the cylinder block and the engine sump.
Crankshaft - the main shaft of the engine, located in the crankcase. The crankshaft has journals to which the connecting rods are connected. This shaft converts the linear motion of the pistons into rotation.
Complex project - disassembly and assembly of the engine with strict adherence to specifications.
Taper- gradual change in diameter along the axis of a shaft or hole. In a cylinder, taper is the result of uneven wear, which is more pronounced at the top than at the bottom.
Main bearing - babbitt plain bearing on which the crankshaft rests.
Crank- an eccentric element of the crankshaft to which the connecting rod is connected.
Crank- an element of the crankshaft to which the connecting rod is connected.
Crank group - machined or reconditioned crankshaft with new main and connecting rod bearings.
Main bearing cap - a cast iron cover that is bolted to the bottom of the cylinder block and supports the main bearing.
Bearing caps - covers secured with bolts or nuts that form the supporting surface of plain bearings or liners.
Highway- a capacious cavity in the cylinder block through which oil is supplied to lubricate moving parts.
Oil deflector- a screen located near the valve stem for throwing off oil.
Oil scraper ring - lower piston ring. There may be several oil scraper rings installed on the piston. This ring serves to remove excess oil from the cylinder wall during piston movement.
Oil clearance - space for the supply of lubricant to the rubbing elements (shaft journals and liners).
Compression ring mark - a small dot or other mark that is located on the top side of the compression ring.
Tap- a tool for cutting threads in a hole.
Mechanical processing - a process that involves removing metal from a work surface by cutting.
N.D. - outer diameter.
Carbon deposits- soft or hard black deposits that accumulate in the combustion chamber, on spark plugs, under the rings and under the valve heads.
Running in- the period of operation during which the grinding and shrinkage of the mating surfaces of new or restored parts occurs. During the break-in period, it is recommended to operate the vehicle in a gentle mode for a certain mileage.
Thrust bearing - a small bearing located in the center of the flywheel (or in the rear tailpiece of the crankshaft), which includes the front tailpiece of the secondary shaft of the gearbox.
Axial play - the distance that the installed shaft can move in the longitudinal direction.
Engine base - a term used to designate the cylinder block, crankshaft, main bearings and connecting rod lower ends as elements of one group.
Jumper between grooves - the part of the piston located between the grooves of the piston rings.
Plastic indicator - a flat strip of plastic material that is used to measure the oil clearance of a plain bearing. The indicator strips are placed on the shaft journals, after which they are installed and tightened with bearing cover bolts. Then the covers are removed, and the thickness of the crushed strips, using a conversion table, is used to determine the size of the plain bearing oil clearance.
Surface treatment - the surface of a part from which material is removed during mechanical processing.
Error- deviation of the result obtained during measurement from the actual value.
Oversize bearings - smaller diameter bearings installed on a re-ground crankshaft.
Piston- a cylindrical engine part that is connected to the connecting rod. The piston moves in the cylinder. and under the pressure of the burning fuel-air mixture, it imparts movement to the crankshaft through the connecting rod.
Piston ring - a ring located in the piston groove and in contact with the cylinder wall. The rings serve to create a seal between the piston and the cylinder, as well as to remove excess oil from the cylinder wall. Depending on their purpose, a distinction is made between compression and oil scraper rings.
Piston pin - a cylindrical, usually hollow pin that passes through the piston and attaches it to the upper head of the connecting rod.
Bearing bed - upper support surface of the main bearing.
Press fit - a tight fit created by the shaft diameter exceeding the hole diameter.
Lapping valves - abrasive treatment of the chamfer and valve seat, resulting in a gas-tight connection.
Wire insert - a repair part used to restore a damaged or worn threaded connection. The insert is installed in the bored hole and forms a thread of the required smaller diameter.
Run- thread restoration with a tap or die.
Scan- a device with ribbed cutting edges, designed for processing cylinder walls.
Camshaft- an engine shaft with cams for driving the valve mechanism. Driven by a toothed belt or chain through a sprocket or toothed wheel.
Boring- mechanical surface treatment performed to increase the size of the cylinder. A boring bar is used for cutting.
Cooling jacket - a cavity around the cylinders, which is located between the cylinder block shells or its head. Cooling liquid circulates in the jacket.
Seal- a sealing element used to prevent oil leakage. Typically a dynamic seal fitted onto the end of a rotating shaft.
Free height- height of the spring in the unloaded state.
Free play - the distance that a lever or pedal moves before the mechanism is activated.
Segment key - key with rounded back side (the rounding is visible from the side).
Saddle- the surface on which the part rests. For example, a valve seat is the surface on which the valve head rests.
Static balance - balance of resting elements.
Compression ratio - the ratio between the cylinder volumes when the piston is at TDC and BDC
Knocking of bearings - the sound produced by the rotation of the elements of a damaged or worn bearing.
Step- a type of wear that appears on the lower part of the bridge between the piston ring grooves. The height of the step determines the lateral play of the rings. The length of the step from the rear wall of the groove determines the clearance of the back side of the rings.
Rusks- a composite fastener that holds the spring plate on the valve stem.
Tact- movement of the piston from BDC to TDC or its path in the opposite direction.
Pusher- a part located between the camshaft cam and the valve stem or rocker arm.
Sealing ring - a ring-shaped sealing element made of the appropriate rubber material. The ring is pressed into the groove to seal the connection.
Thrust washer - a washer made of bronze or hardened steel, installed between two moving elements to limit their longitudinal movement.
Thrust bearing - a main bearing with a thrust surface, due to the presence of which the axial play of the crankshaft is limited.
Truncated block - a replaceable cylinder block assembled with a crankshaft, pistons and, as a rule, a camshaft.
Material fatigue - destruction of the material under the influence of cyclic loads. It appears in the form of cracks, through which the destruction of the part soon occurs.
Installation height - the height of the spring measured in the installed state. For example, the distance from the seat to the back of the valve spring plate.
Hon- a tool driven by an electric motor and used to remove glassy film from cylinder walls during piston ring replacement.
Cylinder- an engine cylinder or other cylindrical hole made in a housing part. The term is used to describe the process of boring or other mechanical processing using cutting tools. The cylinder diameter is equal to the diameter of the main hole.
Cast iron- an alloy consisting of steel and at least 2% carbon compounds. Cylinder heads and blocks are made of cast iron. This is due to the fact that this material is relatively cheap, and also because it is suitable for the production of cast parts.
Connecting rod- a rod connecting the crankshaft crank to the piston.
Connecting rod cap - a part of the connecting rod by which it is attached to the crank pin.
Neck- the part of the shaft that is in the bearing.
Hairpin- a metal rod with threads at both ends.
Key- a small metal part that is inserted into the grooves of two connected parts. If the gear wheel has a keyway fit on the shaft, the presence of the key prevents the elements from turning relative to each other.
Feeler gauge for measuring gaps - a thin metal strip with an engraved thickness. Used to determine the size of the gap by comparison.
Piston skirt - the part of the piston located under the rings and pin holes.
(The original source of the article is the website: «ChevyMan.ru»)