14 CHAPTER ONE Vern ier Ca liper This tool is used to obtain inside, outside and depth measurements. Sec Fi gure 31. Outside Micrometers One of the most accurate tools used for precision mea- surement is the outside micrometer. Outside micrometers are required to measure shim and bearing thickness and piston diameter. Outside micrometers are also used with a telescoping gauge to measure cylinder bore. Micrometers can be purchased individually or as a set (Figure 32), Oial Indica tor Dial indicators (Figu re 33) are used to check crankshaft and drive shaft runout limits. Select a dial indicator with a @ continuous dial (Fig ure 34).
Cyli nder Bore Ga uge The cylinder bore gauge is a very specialized precision toot. The gauge set shown in Figure 35 is comprised o fa dial indicator, handle and various length adapters to adapt the gauge to different bore sizes. The bore gauge can be used to make cylinder bore measurements such as bore size, taper and out-of-round. An outside micrometer must bc used to calibrate the bore gauge. I,'11' '" II 10 1/", "" ,, 30 z: - 2 0~ Telescoping Ga uges Telescoping gauges (Fig ure 36) can be used to measure hole diameters from approximately 8 mm (5116 in.) to 150 mm (6 in.). The telescoping gauge docs not have a scale gauge for direct readings.
An outside micrometer is re- quired to determine bore dimensions. \ ,", '