🔍 Key Concepts

• Side thrust on a piston occurs because the connecting rod is not perfectly in line with the cylinder center line during most of the stroke • Think about how the crankshaft, crank pin, and connecting rod move in relation to the straight up‑and‑down motion of the piston • Side thrust is related to the geometry that makes the piston move linearly while the crankshaft moves in a circular path

💭 Think About

• Which engine parts actually touch the piston and can push it sideways against the cylinder wall? • When the crank is partway through the power stroke, what angle exists that would create a sideways component of force on the piston? • Which option describes an angle that changes during the stroke and could therefore create varying side thrust?

✅ Before You Answer

• Identify which option involves the piston’s linear motion directly (not just rotating parts away from the piston) • Confirm which angle would produce a sideways component of force on the piston, not just rotational torque in the crankshaft • Eliminate any options that do not involve the connecting rod–piston–cylinder relationship during the stroke