Where should piston rings be checked for fit?

Piston rings should be checked for fit both in the piston ring grooves and in the cylinder. Checking in the piston ring grooves ensures that the rings correctly fit within the confines of the grooves, providing proper sealing and alignment during operation. It's essential that the dimensions of the rings match the grooves' specifications to avoid issues like improper sealing or excessive friction.

Additionally, checking the fit in the cylinder is crucial as it allows for the measurement of the ring’s end gap and side clearance when installed in the cylinder bore. This helps verify that the rings can expand adequately and maintain contact with the cylinder walls without excessive wear.

To effectively assess the fit, mechanics often use specific tools and techniques for measuring these dimensions in both locations. Hence, checking the piston rings in both the grooves and the cylinder provides a comprehensive evaluation of their fit and functionality, making it essential for ensuring optimal engine performance.