Jeep Engines - Oljeep

380 MOPAR PERFORMANCE PARTSCRANKSHAFTThe 360 AMC V-8 engine uses a cast nodular ironcrankshaft that rotates within five (5) main bearings and hasa standard bore and stroke of 103.63 x 87.38 mm (4.08 x3.44"). Crankshaft rotation is clockwise, when viewed fromthe front of the engine.The crankshaft has main bearing journal diameters of (Nos.1, 2, 3 and 4) 69.784-69.822 mm (2.7474-2.7489"), a rearmain bearing journal diameter of 69.759-69.797 mm(2.7464-2.7479"), and main bearing journal widths of (No.1) 32.093-32.250 mm (1.2635-1.2695"), (No. 2) 31.650-3 1.700 mm (1.2460- 1.2480"), (No. 3) 32.330-32.390 mm(1.2730-1.2750"), (No. 4) 3 1.650-3 1.700 mm (1.2460-1.2480"), and (No. 5) 30.860-30.910 mm (1.2150-1.2170").The crankshaft has a connecting rod journal diameter of53.172-53.266 mm (2.0934-2.0955"), and a connecting rodjournal width of 50.750-50.900 mm (1.998-2.004").Other Jeep V-8 bore and stroke measurements are:Crankshaft4. Remove the upper insert by loosening all the otherbearing caps and inserting a tool fabricated from a cotterpin approximately 14 mm (1/2") into the crankshaft oilhole. Fabricate a cotter pin as in Figure 7-2.5. With the cotter pin in place, rotate the crankshaft sothat the upper bearing insert is rotated in the directionof its locking tab.6. Remove the remaining bearings in the same manner.r nCOTTER PINJ8909-47Enaine CID (Year)Bore x Stroke290 (1966-69) 3.75 x 3.28"304 (I 972-80)3.75 x 3.44"343 (1967-69) 4.08 x 3.28"390 (1 968-70)4.165 x 3.574"401 (1973-79) 4.17 x 3.68"For more crankshaft specifications, refer to 360 AMC V-8Engine Specifications, 'Engine Assembly' section of thischapter.CRANKSHAFT MAIN BEARINGSReplace crankshafts that are damaged or worn beyondfeasible reconditioning. Use the procedures outlined inShort Block Disassembly, 'Block' section of this chapter, toremove and install a crankshaft.RemovalThe following procedure can be used when the engine isinstalled in the vehicle.1.2.3.Drain the engine oil and remove the oil pan.Remove the main bearing cap and lower insert.Remove the lower insert from the bearing cap.IInspectionFigure 7 - 21. Wipe the inserts clean and inspect for abnormal wearpatterns and for metal or other foreign materialimbedded in the lining.2.3.4.5.If any of the crankshaft journals are scored, remove theengine for crankshaft repair.Inspect the back of the inserts for fractures, scrapingsor irregular wear patterns.FittingInspect the upper insert locking tabs for damage.Replace all damaged or worn bearing inserts.The main bearing caps are numbered 1 through 5, front torear, with an arrow to indicate the forward position. Theupper main bearing insert surfaces are grooved. The lowerinsert surfaces are smooth.Each bearing insert pair is selectively fit to its respectivejournal to obtain the desired operating oil clearance. Inproduction, the select fit is obtained by using various-sizedcolor-coded main bearing inserts as listed in the MainBearing Fitting Chart (Figure 7-3). The bearing color codeappears on the edge of the insert. The bearing size is notstamped on production inserts.T -T7