Jeep Engines - Oljeep

258 MOPAR PERFORMANCE PARTS5.6.7.8.9.10.11.12. Honing Plates (refer to ‘Block’ section of this chapter).13.14.Once the main bearing bores are known to be inalignment, the deck surfaces of the block should bechecked to make sure they are parallel with the axis ofthe crankshaft. The distance from the centerline of thecrankshaft to the deck surface of the block should beexactly the same in the front and rear. If not, the decksurfaces will have to be milled. At this time the deckheight can be machined to the proper dimension.Note: Deck heights that are above the block surfacewill be increased by milling the block. Check theblueprint specifications on the engine before milling.The resulting machined surface of the deck must be onthe rough side to produce a good gasket seal andprevent the head gasket from moving.A bottoming tap should be run down all head and mainbearing bolt holes. The head bolt holes should bechamfered slightly to prevent the top thread frompulling up when the head bolts are torqued.Use a small, fine file to remove burrs and break allsharp edges in the main bearing bores and around thecylinder bore chamfers, along with other sharp edgeson the block.The tappet bores may be shined with #400 paper toremove any rough spots or burrs. A brake cylinderhone may also be used with care.If a big flat-tappet camshaft that requires .loo”oversize mushroom lifters is going to be used, thebottoms of the lifter bores should be spot-faced to aslightly larger diameter than the diameter of themushroom lifter bottom.Ensure that all cylinder head dowel pins used foraligning purposes are the proper height (not too high),and also check to be sure that the dowel pins locate thehead properly so that the combustion chamber iscentered over the cylinder bore. Check to be sure thatthe dowel pins don’t hold the head up off the block.Honing (refer to ‘Block’ section of this chapter).The rear main bearing oil seal machined groove shouldbe roughed slightly with a center punch, and the ropeseal must be seated all the way in. The rubber rear mainseal should be held in place with Permatex (RTV).A chemical kit belongs in every workshop before you startbuilding the engine. It will be useful in coping with life’smechanical frustrations, such as baked-on gaskets,assuring proper seal, assembly lubing, freeing up nuts, anddozens of other uses. Chemical products to be usedfrequently are: Silicone RTV, Gasket Remover, Lubriplate,Spray White Lube, Anaerobic Gasket Maker, Lock ’NSeal, Brake and Carburetor Cleaner, Penetrating Fluid,Spray Gasket Adhesive, Thread Sealant with Teflon, andHand Cleaner. Everything you’ll need to spare a headache!15. When installing camshaft bearings, make sure that theoil holes in the bearings line up with the oil holes in theblock. DO NOT replace camshaft bearings unless theyare bad.16. When all machine operations are complete, the blockshould be thoroughly washed out with solvent. Usebottle brushes of suitable size to clean out all bolt holes,oil passages, etc. Finish off with another thoroughwashing using a good, common detergent and warmwater. Blow or wipe dry and oil to prevent rust. Engineparts can’t be too clean. Many early engine failures canbe traced to dirt or foreign objects (metal chips, etc.)that were left in the engine when it was reassembled.Crankshaft1.2.3.4.5.6.Check crankshaft end play (refer to Crankshaft EndPlay, ‘Crankshaft’ section of this chapter).Crankshaft bearing journals should be checked forspecified diameter and clearance. If it is a hardenedcrankshaft, it shouldn’t be ground for clearance. Thesecrankshafts are hard only to a depth of .0003”. The mainbearing clearances should also be checked. The best wayto measure crankshaft journals is with a micrometer.Main bearing clearances can be measured directly or byusing Plastigauge. The main bearing clearances shouldbe 0.03-0.06 mm (0.001 -0.0025”). For completeprocedure, refer to Measuring Main BearingClearances, ‘Crankshaft’ section of this chapter.The bearing journals may be polished by hand, firstwith #400 and then with #600 paper. Any nicks, burrsor scratches should be polished out. Chamfer oil holesin journals and use a wet stone to break edges. Checkthe oil passages to each journal.Caution: With nodular cast iron crankshafts, it isimportant that the final paper or cloth polish after anyjournal regrind be in the same direction as normalrotation in the engine.Before assembly, make sure crankshaft, includinginternal oil passages, is clean. Also be sure all oilingpassages are drilled through.When assembling the crankshaft into the block, oil thebearings and journals.When installing the crankshaft, locate the main capscarefully so that the crankshaft spins freely, and torque allcaps to specification. Then spin the crankshaft by handthrough several revolutions before installing the rear mainseal. It should be fairly free, requiring very little effort.Remove the caps and check for any burrs. If present, theycan be removed by gently scraping with a bearing knife.When installing the rear main seal, make sure it is properlyseated improper seating can cause the crankshaft to bind.-~