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techtalk:evo:engmech04c [2019/02/02 03:08] – [Installing the Rocker Boxes] hippysmack | techtalk:evo:engmech04c [2024/01/04 01:22] (current) – hippysmack | ||
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- | ====== EVO: Engine Mechanicals - Sub-04A ====== | + | ====== EVO: Engine Mechanicals - Sub-04C ====== |
====== Installing the Rocker Boxes ====== | ====== Installing the Rocker Boxes ====== | ||
See also in the Sportsterpedia; | See also in the Sportsterpedia; | ||
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* [[techtalk: | * [[techtalk: | ||
\\ | \\ | ||
- | One issue in installing the rocker box is that it has no alignment method. ((aswracing of the XLFORUM | + | One issue in installing the rocker box is that it has no alignment method. ((aswracing of the XLFORUM |
Basically, every time you put it on, it's in a different place. \\ | Basically, every time you put it on, it's in a different place. \\ | ||
- | When installing the rocker boxes, be sure to put them on with the engine positioned such that the cams aren't trying to open the valves. ((aswracing of the XLFORUM | + | When installing the rocker boxes, be sure to put them on with the engine positioned such that the cams aren't trying to open the valves. ((aswracing of the XLFORUM |
Else you can damage parts. \\ | Else you can damage parts. \\ | ||
+ | |||
+ | ===== Compatibility ===== | ||
+ | Middle rocker box: \\ | ||
+ | The 86-90 doesn' | ||
+ | So due to functionality, | ||
+ | But the 91-03 middle cover will fit 86-90 boxes. \\ | ||
+ | |||
+ | ===== Gaskets ===== | ||
+ | Clean the mating surfaces of all oil / trash before setting the gaskets in place. \\ | ||
+ | With the bolts ' | ||
+ | It's easy to 'just nudge' the top section and squeeze a portion of the rubber gasket out while positioning it. \\ | ||
+ | See [[http:// | ||
+ | |||
+ | {{: | ||
+ | |||
===== Bolt Installation Sequence ===== | ===== Bolt Installation Sequence ===== | ||
The FSM details the proper installation sequence of the bolts. \\ | The FSM details the proper installation sequence of the bolts. \\ | ||
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The circled areas are where the bolts would be: \\ | The circled areas are where the bolts would be: \\ | ||
- | **On assembly**: ((Screw Loose Dan of the XLFORUM | + | **On assembly**: ((Screw Loose Dan of the XLFORUM |
* Work in this order. Blue-> | * Work in this order. Blue-> | ||
* An easy way to remember the order is to work from the larger bolts to the smaller ones. | * An easy way to remember the order is to work from the larger bolts to the smaller ones. | ||
+ | * If you start with the red ones, you can easily strip the threads in the heads. | ||
**Torque values**: \\ | **Torque values**: \\ | ||
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* Yellow - 135-155 in-lbs | * Yellow - 135-155 in-lbs | ||
- | |91-03 style lower rocker box ((photo by Hippysmack))|04 and up style lower rocker box ((photo by Screw Loose Dan of the XLFORUM | + | |91-03 style lower rocker box ((photo by Hippysmack))|04 and up style lower rocker box ((photo by Screw Loose Dan of the XLFORUM |
|{{: | |{{: | ||
+ | |||
+ | ===== Check Pushrod Length ===== | ||
+ | A hydraulic lifter has a plunger in it's body that has about .200" of movement. ((http:// | ||
+ | In the ideal world, the plunger is approximately centered in it's travel, meaning it's preloaded about .100". \\ | ||
+ | So in theory,\\ | ||
+ | It could move up, thus lengthening the effective length of the lifter to compensate for a pushrod that's up to .100" too short. \\ | ||
+ | And likewise, it could move down, thus shortening the effective length of the lifter to compensate for a pushrod that's up to .100" too long. \\ | ||
+ | This self adjusting action is also useful for compensating for changes in needed pushrod length due to engine temp variations. \\ | ||
+ | As the motor heats up, the top end grows and the lifter automatically takes up the slack. \\ | ||
+ | In reality, \\ | ||
+ | The useful operating range of the lifter plunger is only about .050" in either direction away from centered (.050" to .150" of preload). \\ | ||
+ | Outside of this range, the self adjusting function doesn' | ||
+ | |||
+ | You can measure lifter pre-load to determine if the pushrods are in the size range needed. This method will get you close. ((http:// | ||
+ | The cam lobes should be down (as they should be when installing a rocker box). \\ | ||
+ | Set the pushrods in place (the longer one goes on the exhaust) and then place the gasket and rocker box on top installing the four big screws only. \\ | ||
+ | Finger tighten the left (spark plug) side, while making sure the right side is resting with the upper pushrod ends sitting in the cups on the rocker arms. \\ | ||
+ | Use a caliper to measure how much gap you have between the rocker box and the rocker box gasket. \\ | ||
+ | The lifter preload should be app. .100" but anywhere between .050" and .150" should work. \\ | ||
+ | Aftermarket pushrods can be purchased in longer or shorter lengths than stock ones to get the measurement within .100". | ||
+ | |||
+ | {{: | ||
\\ | \\ |