Jeep Engines - Oljeep

*I182 MOPAR PERFORMANCE PARTSIf you're going to swap camshafts, you've spent goodmoney for a new camshaft and you want to improve on thestock one or whatever is currently in the engine. If you DONOT centerline, then you DO NOT get the full value ofyour investment and you probably won't achieve thedesired improvement. Once the engine is disassembled tothe point of installing the camshaft, centerlining thecamshaft costs very little and only takes a few minutes todo. If you have a problem with the engine's performanceafter assembly, you will ultimately need to centerline thecamshaft. Centerlining may be a minor problem of a fewdegrees or a major problem of a tooth or two on thecamshaft sprocket. Usually the problem isn't with thecamshaft itself, except relating to installation; i.e.,centerline. By centerlining the camshaft at installation, youcan concentrate on carburetors, ignition, and assemblyproblems (such as gasket leaks) to identify any problem.But if you didn't centerline the camshaft, you can't say forsure that it is the carburetor, ignition, etc. To centerline thecamshaft with the engine together requires partialdisassembly. This is a lot of extra work. One added benefitof centerlining relates to advancing or retarding thecamshaft for improved performance. You don't knowwhich direction or the number of degrees to change if youdon't know the original centerline first.Note: When checking camshaft centerline, ALWAYSrotate the engine clockwise from the front. This is thenormal direction of engine rotation. By rotating the enginein this manner, the clearances in the camshaft drive system(chain, sprockets, keys, etc.) will be taken up just as theyare when the engine is firing, and your measured camshaftcenterline will be what the engine sees when it is firing.The procedure is as follows:With the camshaft in place, insert the intake valvetappet for the No. 1 cylinder.Place a dial indicator on the tappet parallel to the tappetcenterline or on the retainer parallel to the valve centerline.Install a degree wheel (P4452990) so its pointerindicates TDC when the No. 1 piston is at TDC.Turn the engine over (clockwise from the front) untilthe dial indicator is at maximum camshaft lift. Zero theindicator at this point.Turn the engine over (clockwise from the front) untilthe indicator reads .025" before reaching maximumlift. Stop. Read the degree wheel and write down thenumber of degrees. Continue rotating the engine in thesame direction (clockwise) past maximum lift (zeroindicator reading) until .025" is read again on theindicator. Stop. Read the degree wheel. Write it down.Add the two degree wheel readings and divide by two.The answer is the camshaft centerline.Note: The .025" was used for illustration. Anymeasurement above .020" is acceptable.Example: Let's assume that you are going to use acamshaft with a centerline of 110". Now let's go throughthe installation procedure with this camshaft. We'll installthis 110" camshaft at 108" centerline.The camshaft and timing chain or gear drive are installed.The lifter is installed on the No. 1 intake lobe. The degreewheel is bolted to the crankshaft and set to read TDCcorrectly with a pointer. The dial indicator is zeroed at themaximum lift of the camshaft. Now, rotate the engineclockwise and approach the indicator reading of .020"carefully, since you must not reverse the direction ofrotation. At .020" the degree wheel reads 90". Record thereading and continue to rotate the engine clockwise throughzero until the indicator reads .020". The degree wheel nowreads 134". Add 90" plus 134" and divide by two. Answer:112". Thus, you must advance the camshaft 4" in order tohave the centerline at 108". Offset bushings (P3690936) areused for this purpose. (360 AMC V-8 engines use offsetkeys.) Use the proper offset bushing (or key) so that thecenterline of the camshaft is moved forward (advanced) inthe direction of its rotation.Now repeat the steps with the advanced camshaft position.You should read 86" at .020" before maximum lift on theindicator and 130" at ,020" after maximum on the indicator.Add 86" to 130". Answer 2 16". Divide this by two. Answer108". The camshaft is now installed correctly. If ,040" wasselected instead of .020" for the indicator reading, the laststep would be as follows. You would read 70" at .040"befoire maximum lift and 146" at ,040" after maximum lift.The two numbers added together yield 216" and thisdivided by two gives 108".Note: Changing the camshaft centerline 1in engine performance.will not be seenIf you DO NOT have a degreed damper, damper degreetiming tape (P4.529070) is recommended.Damper Degree Timing TapeImprove timing accuracy of your engine with this timing tapepackage. Marked in 90" increments. Self-adhesive stripadheres to crankshaft vibration damper for clear identificationof marks. Permits initial total spark advance up to 60" insteadof only 10"-15" as on chain case timing tab. Works on all 7-1 /4" diameter non-grooved vibration dampers.P4.529070 Damper degree timing tape.TDC Indicator ToolThis is a handy, positive-stop tool for determining exactTop Dead Center (TDC) when centerlining camshafts.This tool, of hardened steel, is extremely accurate and canbe used on all DaimlerChrysler engines. It takes theguesswork out of finding TDC.P434'3737TDC indicator tool.