Jeep Engines - Oljeep

360 AMC V-8 (CAMSHAFT AND VALVE GEAR) 403VALVE SEATSWith cast iron cylinder heads, all the valve seats aremachined into the head material. (Aluminum heads usevalve seat inserts.) One of the most important items in ahigh output engine is the valve job.Valve Seat RefacingInstall a pilot of the correct size in the valve guide andreface the valve seat to the specified angle with a dressingstone in good condition (Figure 7-25).Remove only enough metal to provide a smooth finish. Thisis especially important on exhaust valve seats. The seathardness varies in depth.Use tapered stones to obtain the specified seat widths whenrequired. Measure the seat runout with a dial indicator(Figure 7-26). Maximum seat runout is 0.064 mm (0.0025").VALVE TIMING1.2.3.4.5.6.7.8.9.10.Remove the spark plugs.Remove the cylinder head covers and gaskets.Remove the bridge and pivot assemblies and rockerarms from the No. 1 cylinder.Rotate the crankshaft until the No. 6 piston is at topdead center (TDC) on the compression stroke. Thispositions the No. 1 piston at TDC on the exhaust strokein the valve overlap position.Rotate the crankshaft counterclockwise 90" as viewedfrom the front.Install a dial indicator on the No. 1 intake valvepushrod end. Use rubber tubing to secure the stem onthe pushrod.Set the dial indicator at zero.Rotate the crankshaft slowly in the direction of normalrotation (clockwise, viewed from the front) until thedial indicator indicates 0.508 mm (0.020").This should align the milled timing mark on the vibrationdamper with the TDC mark on the timing degree scale. Ifa variation of more than 13 mm (1/2") exists in eitherdirection from the TDC mark, remove the timing casecover and inspect the timing chain installation.Inspect for an incorrect camshaft sprocket location.The sprocket keyway should align with the centerlineof the first lobe of the camshaft.ROCKER ARMSFigure 7 - 25The most important considerations in rocker arms arestrength and durability. Strength is required to minimizedeflections and transfer the cam motion to the valveaccurately. One important item in high performancehydraulic cams is that the higher valve spring loadsrequired by these cams put more load on the rocker arms,which causes the pushrods to have a tendency to pierce therocker arm. Thicker material in the pushrod ball or cup areais the only solution to this problem.Heavy Duty Rocker ArmHeavy duty stamped rocker arms for use with hydrauliccams (only). Right and left rockers are the same. Can beused to service stock engines. For 360 AMC V-8 engineonly. (Sold individually.)P45296 19Heavy duty rocker arm,Figure 7 - 26