Jeep Engines - Oljeep

4.0L POWER TECH IN-LINE 6 (CAMSHAFT AND VALVE GEAR) 17915. Install the cylinder head. Refer to Cylinder HeadInstallation, ‘Cylinder Head’ section of this chapter forthe procedure.16. Install the pushrods.17. Install the rocker arms and pivot and bridgeassemblies. Tighten each of the two capscrews for eachbridge alternately one turn at a time to avoid damagingthe bridge.18. Install the cylinder head cover. Refer to Cylinder HeadCover Installation, ‘Cylinder Head’ section of thischapter for the procedure.19. Install the A/C condenser and receiveddrier assembly,if equipped. Refer to the service manual for additionalinformation pertaining to the A/C system.Caution: Both service valves must be opened beforethe air conditioning system is operated.20. Install the radiator, connect the hoses and fill thecooling system to the specified level. Refer to theservice manual for the proper procedure.21. Check the ignition timing and adjust as necessary.22, Install the grille and bumper, if removed.23. Connect the battery negative cable.CAMSHAFT INSTALLATION TIPS1.2.3.4.5.When installing the camshaft sprocket, use at leastGrade 8 bolts with Loctite and safety wire. It ispossible for high speed engine harmonics to causethese bolts to loosen if precautions aren’t taken. (Notrequired while centerlining the camshaft.)Because of the production tolerances mentionedearlier, it is possible for the crankshaft-to-camshaftrelation to be several degrees off, either advanced orretarded. It is important that this timing be correct toproduce maximum performance.While the engine is still without heads, the timing markson the crankshaft damper and the timing chain covershould be checked for accuracy of the “0” TDC mark.Advancing or retarding a camshaft should only be doneto install the camshaft at its designed centerline. It isvery important to have the centerline correct. Mostcamshafts will have the design centerline stated as partof the specifications along with duration and lift. If itisn’t given, it can be calculated. Advancing orretarding a camshaft from its designed centerline is notrecommended because it will cut down on the overallefficiency of the engine (although there are exceptionsto this general rule).Before installation, the camshaft and tappets should beliberally coated with Mopar Engine Oil Supplement.This lubricant will stick to the surface without drainingoff and will prevent scuffing when the engine is firedup for the first time. It has been determined that this iswhen most camshaft damage takes place.7 7 TT-