2Engine Block Assembly Very sophisticated casting. Made of cast iron or aluminum with cast iron cylinder liners.A great deal of machining involved in the process of manufacturing.Becomes the frame of the engine.
4Bottom End Parts Block Crankshaft Connecting Rod Pistons, Rings, & Wrist PinBearings (Main and Connecting rod)Caps (main and Connecting Rod)Fly Wheel and nuts and bolts
5Cylinder Block Common cylinder configurations: Vee, inline, opposed And slant.Number from farthest front backwards
6Crankshaft Converts reciprocating motion into rotary motion. Made of either nodular iron, forged steel, or billet steel.
7Crankshaft Terminology Crankpins or throwsMain bearing journalsRod bearing journalsThrust bearingMain capsOil passagesFlywheel flangeVibration damper endKeywayRear main sealFront crankshaft sealCounter weightsFiring order
8Crankshaft Bearings Known as friction or precision insert bearings. Uses a steel backing with soft metal on crankshaft side.(lead,tin, copper, silver, cadmium)Oil clearance between crankpin and bearing very critical. (.001”)Oil Clearance measured with plastigauge.
10FlywheelThe flywheel (known as the flex plate when used with an automatic transmission) carries the engines inertia in between power strokes.It is the power take off for the engine. The clutch or torque converter bolts to it.Lastly it has the starter motor’s ring gear.
11Vibration DamperThe vibration damper smoothes the vibrations caused by the power strokes.It has a pulley on it the run auxiliary systems.It may contain timing marks or crankshaft timing sensors.
12Balancer ShaftsUsed to counteract the normal vibrations inherent to piston engines.Found on 4 cylinder and 6 cylinder engines mostly.
13Covers & Pans Made of steel metal, aluminum, or plastic materials. Usually use gaskets or seals.
14Gaskets, Seals and Sealers Gaskets seal two stationary surfaces.Seals do it when one surface moves.Many types of materials: rubber, paper, aluminum, steel, cork and more.Sealers adhere gaskets to one of the surfaces.
15Pistons Pistons harness the energy of the power stroke and transfers theforce towardthe crankshaft.
16Piston Terminology Head or crown Ring grooves Ring lands Oil return holesSkirtPin holePin bossPin offset
18Piston RingsRings seal the compression in the combustion chamber and the motor oil in the crankcase.Automotive engines use 3 rings: 2 compression and 1 multi-piece oil ring.
19Piston Ring Wear Causes a loss of compression. Causes excessive oil consumption. May cause blue smoke out the tail pipe.
20Types of Piston Rings Rings are usually made of cast iron can be plated with chrome or molybdenum.Help seal the ring to the cylinder wall.Shapes of the ring vary to also help the ring seal better.
21Piston Pin (Wrist Pin) Hollow polished steel pin. Attached in a variety of ways.Pinned to piston.Clamped to rod small end.Snap ring free floating.Press fit.
22Connecting RodsI-beam style rod use to transfer the pistons force to the crankshaft.Small end contains the piston pin and the big end has a removable cap to install it to the Crank.Nuts and bolts are usually of a very high quality.
23Installation of Pistons Cylinder numberPiston numberNotch to the frontPosition ring gapsRemove rod cap check bearing insertsCover bolts with fuel line if neededCrankshaft at TDC or BDCInstall ring compressorOil piston, cylinder wall, & crank journalCarefully tap in piston with hammer handle.Properly replace rod cap
25Weird Science of Engines Free running and Non-free runningCrankshaft rotation versus piston travelPiston side thrustPiston pin offsetCylinder bore wearCrankshaft journal wear
26Free and Non-Free running Engines Free running engines can have their piston at TDC and their valves wide open and the valve won’t touch the piston.Non-free running engines will crash the valves into the piston if the piston is at TDC and the valves are wide open. This will wreck the engine.
27Piston Travel Verses Crankshaft Rotation When the piston move ½ way down the bore the crankshaft does not turn a ½ a turn. This will always create vibration.
28Piston Side Thrust There are two sides to the piston. The thrust side and the relief side.Wear occurs mainly on the thrust sides.Skirt area is not even needed on the relief side.Piston pin offset counteracts side thrust.
29Cylinder Bore Wear Wears oval shaped. Cylinder wall tapers. Pocket forms near the top.A ridge forms at the top.
30Cylinder BoringCylinders can be bored to restore them however they will be larger requiring bigger pistons.Usually bored to .010”, .020”, .030”, or .050”
31Crankshaft Wear Wears out of round due to the power strokes. Grinding can restore the journals, however they are smaller requiring under sized bearings.