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techtalk:evo:engmech04a [2019/02/12 17:15] hippysmack [About Relieving Valve Pressure] |
techtalk:evo:engmech04a [2019/02/12 17:41] hippysmack [About Relieving Valve Pressure] |
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| You are not actually doing anything but allowing the oil time to leave the lifter body out of the holes in the each lifter before removing the lower rocker mounting bolts. \\ | You are not actually doing anything but allowing the oil time to leave the lifter body out of the holes in the each lifter before removing the lower rocker mounting bolts. \\ | ||
| Due to viscosity of the oil and hole locations, it usually takes 20-30 minutes. | Due to viscosity of the oil and hole locations, it usually takes 20-30 minutes. | ||
| + | Internal clearance and parts determine bleed rates. ((bustert of the XLFORUM http://xlforum.net/forums/showthread.php?t=2039673&highlight=bleed+lifters)) | ||
| **The 86-03 FSMs state to rotate the crankshaft so both valves are closed on the head being repaired**. \\ | **The 86-03 FSMs state to rotate the crankshaft so both valves are closed on the head being repaired**. \\ | ||
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| |Photos of a dry lifter. (L) assembled - (R) with spring pressure at rest. On dry assembly, the pushrod cup is \\ relatively easy to push in with you finger to install the retainer clip. If oil was poured into the lifter body and \\ then the cup was compressed, it would be more difficult to push the cup down to install the retainer. ((photos by Hippysmack)) || | |Photos of a dry lifter. (L) assembled - (R) with spring pressure at rest. On dry assembly, the pushrod cup is \\ relatively easy to push in with you finger to install the retainer clip. If oil was poured into the lifter body and \\ then the cup was compressed, it would be more difficult to push the cup down to install the retainer. ((photos by Hippysmack)) || | ||
| |{{:techtalk:ref:svcproc:lifter_disassembly_2_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:svcproc:lifter_disassembly_6_by_hippysmack.jpg?direct&300|}}| | |{{:techtalk:ref:svcproc:lifter_disassembly_2_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:svcproc:lifter_disassembly_6_by_hippysmack.jpg?direct&300|}}| | ||
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| + | **Cam lobe positions**: | ||
| + | Rocker boxes should really only be removed and installed when the cams are positioned such that the lifters are let all the way down. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=5041422&highlight=rocker+box#post5041422)) \\ | ||
| + | Compression TDC is the best place to do this, because it's just about exactly halfway through the valve-closed window. \\ | ||
| + | If you install the rocker boxes at overlap TDC instead, both valves are slightly open. So it's important to be able to tell compression TDC from overlap TDC. \\ | ||
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| + | Ten minutes or so is a pretty normal amount of time for lifter bleed down. \\ | ||
| + | It may take longer if it's particularly cold or if you're using heavy oil. \\ | ||
| + | But if you're sitting at overlap TDC, you may never see the valves close because the lifter will shorten as far as it goes and still be too long. \\ | ||
| **There are two TDC's for EACH cylinder**. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1874585)) \\ | **There are two TDC's for EACH cylinder**. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1874585)) \\ | ||
