Jeep Engines - Oljeep

~ ~~~Engine Assembly4.2L IN-LINE 6 (ENGINE ASSEMBLY) 333Note: For engine assembly information, performance modifications and tips, refer to 'Engine Assembly' section of Chapter4,4.0L Power Tech In-Line 6.1981, 4.2L ENGINE SPECIFICATIONSNote: The following information has been reprinted from the 1!381 Jeep Sewice Manual.Type ...................(USA)1nCh.rUnlaOthnvviuSp.cifid(METRIC)MillimetersUnlasOtherwise-ifidIn Line, OHV, Six-CylinderBore ................... 3.7595.25Stroke258. ................. 3.895 98.93Displacement258. .................258 cubic inches 4.2 litersCompression Ratio ...........8.0: 1Compression Pressure258.. ................ 1M150pl 827-1034kPaMaximum Variation BetweenCy I i nden............... 30 psi 206 kPaFiring Order. ..............1-5-3-6-24Taxable Horsepower .......... 33.75 Bhp 25.2 kW...................Fuel.CamshaftFuel Pump Eccentric Diameter ....Tappet Clearance ............End Play. ................Bearing Clearance. ...........Bearing Journal DiameterNo. 1. ................No.2 .................No.3 .................No. 4. ................Base Circle Runout. ..........Cam Lobe Lift. .............Intake Valve TimingOpens. ................Closes. ................Exhaust Valve TimingOpens. ................Closes. ................Valve Overlap ..............Intake Duration. ............Exhaust Duration. ...........unleaded1.615-1.625 41.0241.28Zero Lash (Hydraulic tappets)Zero (engine operating)0.001-0.003 0.025-0.0762.029-2.030 51.54-51.562.01 9-2.020 51.28-51.312.009-2.010 51.03-51.051.999.2.000 50.78-50.800.001 (max) 0.03 (maxl0.253 8.4390 BTDC73O ABDC57' BBDC25' ATDC340262026PConnecting RodsTotal Weight (less bearings)(USA)InchesUnlessOtherwiseSpecified258 . ................. 695-703 grams(METRIC)MillimetersUnlessOtherwiseSpecifiedTotal Length (center-tocenter)258. ................. 5.873-5.877 149.17-140.28Connecting Rod Bore (less bearings) . 2.2085-2.2080 56.09-56.08Bearing Clearance. ........... 0.001-0.0025 0.03-0.06(0.0015-0.002 (0.044preferred) preferred)Side Clearance. ............. .01 G.019 .25-.48Maximum Twist. ............ 0,001 per inch 0.025 per25.4 mmMaximum Bend. ............ 0.0005 0.01 27 perper inch 25.4 mmcr8nluhdtEnd Play. ................ 0.00150.0065Main Bearing Journal Diameter .... 2.4986-2.5001Main Bearing Journal WidthNo. 1. ................ 1.0861.098No.3. ................ 1.271-1.273No. 24-567 ............ 1.182-1.188Main Bearing ClearanceNo. 1 Main. ............. .OOO5 to .0026Loo1 5preferred)No. 2,3,4,5. & 6 Mains. ..... .0005 to .003(DO17preferred)No. 7 Main. ............. .0011 to .0035( DO23preferred)Connecting Rod Journal Diameter . . 2.0934-2.0955Connecting Rod Journal Width .... 1.070-1.0760.038-0.16563.464-63.50227.58-27.8932.28-32.3330.02-30.18.013 to .066( .04preferred).013 to .076( .045preferredl.028 to .OW( .058preferred)53.17-53.2327.18-27.3360263ArT r-r