POWERPLANT ORAL QUESTIONS AND ANSWERS

What procedure should be followed when valve blow-by is indicated by a hissing sound on a reciprocating engine when pulling the propeller through? - Answer-Perform a cylinder compression test to identify the faulty cylinder. What is the running valve clearance on engines equipped with hydraulic valve lifters? - Answer-Zero. When troubleshooting a running engine malfunction, what does a cold cylinder indicate? - Answer-Lack of combustion in that cylinder. What factors about the condition of an engine can be learned by studying the results of a compression test? - Answer-The results of a compression test determine if the valves, piston rings, and pistons are adequately sealing. What should be done to repair a loose stud in an engine crankcase? - Answer-Remove the loose stud, and inspect the hole for size and the condition of the threads. It may be necessary to use a suitable oversize stud. How is a cylinder barrel inspected for out of roundness? - Answer-A dial indicator (or a telescopic gauge and micrometer, or an inside micrometer) can be used to measure at the top of the cylinder and also at the skirt. Two readings should be taken, 90 degrees to each other. What types of connecting rods are commonly found in radial engines? - Answer-Master and articulated rod assemblies. What are the different types of piston rings? - Answer-Compression, oil control, and oil scraper. What is the purpose of oil control rings? - Answer-Oil control rings regulate the thickness of the oil film on the cylinder wall. What types of bearings are in general use in reciprocating engines? - Answer-Plain, ball, an