Jeep Engines - Oljeep

T --I ri2.5L POWER TECH IN-LINE 4 (BLOCK) 31Figure 2 - 9OILHOLEJ9009-514. Determine taper by subtracting the smaller diameterfrom the larger diameter.5.Rotate measuring device 90" and repeat steps above.6. Determine out-of-roundness by comparing thedifference between each measurement.7. If cylinder bore taper does not exceed 0.025 mm(0.001") and out-of-roundness does not exceed 0.025mm (0.001"), the cylinder bore can be honed. If thecylinder bore taper or out-of-round condition exceedsthese maximum limits, the cylinder must be bored andthen honed to accept an oversize piston. A slightamount of taper always exists in the cylinder bore afterthe engine has been in use for a period of time.10mm -(3/8 IN.)-MIDDLEwBORE13/8 10mm OF 1N.I-.-. - .USE FORSIZINGPISTONww9509-27Figure 2 - 11Cylinder Bore ReconditioningFigure 2 - 10Cylinder Bore Measurement1. It is mandatory to use a dial bore gauge to measureeach cylinder bore diameter (Figure 2-1 1). To correctlyselect the proper size piston, a cylinder bore gaugecapable of reading in 0.003 mm (.0001")INCREMENTS is required. If a bore gauge is notavailable, DO NOT use an inside micrometer.2.3.Measure the inside diameter of the cylinder bore atthree levels below top of bore. Start perpendicular(across or at 90 degrees) to the axis of the crankshaftand then take two additional readings.Measure the cylinder bore diameter crosswise to thecylinder block near the top of the bore. Repeat themeasurement near the middle of the bore, then repeatthe measurement near the bottom of the bore.Caution: DO NOT use rigid type hones to removecylinder wall glaze.1. Use an expanding type hone on the cylinder bore toremove glaze for faster piston ring seating. Move thehone down and up (stroke) at sufficient speed to producea uniform 60" angle crosshatch pattern on the cylinderwalls. DO NOT use more than ten (10) strokes percylinder (one stroke is one down-and-up movement).2.3.Scrub the cylinder bores clean with a wlution of hotwater and detergent.Immediately apply light engine oil to the cylinderwalls. Wipe with clean, lint-free cloth.