2026 Jeppesen Powerplant Oral

What is the purpose of dynamic dampers on crankshafts?

They reduce engine vibration

What types of bearings are generally found in reciprocating engines?

Plain, ball and roller bearings

Are the connecting rods used in each cylinder of a radial engine the same? Explain.

No. Radial engines use master and articulating rod assemblies.

Name the different types of piston rings.

Oil control, compression and oil scraper

Where should piston ring gaps be installed relative to each other, and why?

Compression ring gaps should be staggered so that they do not align. This prevents excessive blow-by

What could result from incorrectly installed piston rings?

Excessive oil consumption

What purpose do oil control rings serve?

They regulate the thickness of the oil film on the cylinder walls

What is used to help prevent valve surge or floating in an aircraft engine?

\vo or more springs are used on each valve.

On engines equipped with hydraulic valve lifters, what should the running valve clearance be?

Zero

What is the purpose of valve overlap?

It allows better volumetric efficiency and lowers cylinder operating temperatures