1. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

2. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Four-Stroke Cycle

3. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Refers to the block, crankshaft, connecting rods, pistons.

4. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Engine Bottom End

5. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Crankshaft  Changes the reciprocating (up-and- down) motion of the pistons into rotating motion.

6. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Journals are precision-ground surfaces for the bearings Crankshaft Parts

7. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Flywheel  Flywheel:  connects the crankshaft to the transmission  contains a large gear, which meshes with the starting motor gear to start the engine

8. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Connecting Rod  Transfers piston movement to the crankshaft.

9. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Piston Transfers the pressure of combustion to the connecting rod and crankshaft

10. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Piston (Wrist) Pin Allows the piston to swing on the connecting rod

11. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Piston Rings  Seal the clearance between the outside of the piston and the cylinder wall  Keep combustion pressure from entering the crankcase  Keep oil from entering the combustion chambers

12. © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only The End