Topic: Rockers hitting caps

[TwoTired]

Get familiar with the "rubber band trick" before you install that new beauty.


http://forums.sohc4.net/index.php?topic=124110.0

Since my lash adjustment were starting from nothing I backed them all off to the max and it went on quite easily.  Next time I pull it I'll band it so it's less work.  Thanks!

Oh crap, I hope that works out for ya.  But, even backing out the adjusters is not enough caution.  You absolutely MUST ensure that no part of any rocker places side pressure on the valve stem.  And, that is nearly unavoidable due to cam lobe profile trying to open some of the valves as the cover is torqued down.

[Trad]

Get familiar with the "rubber band trick" before you install that new beauty.


http://forums.sohc4.net/index.php?topic=124110.0

Since my lash adjustment were starting from nothing I backed them all off to the max and it went on quite easily.  Next time I pull it I'll band it so it's less work.  Thanks!

Oh crap, I hope that works out for ya.  But, even backing out the adjusters is not enough caution.  You absolutely MUST ensure that no part of any rocker places side pressure on the valve stem.  And, that is nearly unavoidable due to cam lobe profile trying to open some of the valves as the cover is torqued down.

So what is your method for torquing the cover? if it's unavoidable what are the steps? I'm in the midst of a rebuild and have heard this caution several times.

To the OP. that shaft wear is nuts! my 550 has similar milage to yours and I also have the old style cover. My rocker shafts are all centre and I don't have any cap connection. I wonder why this would vary bike to bike?

This is what I have going on ATM

[TwoTired]

So what is your method for torquing the cover? if it's unavoidable what are the steps?

It is sort of a torque a little and test for contact.  Loose rockers and backed out adjusters are no threat.  Snug the bolts and find the rockers making valve stem contact.  Be damn certain the ones in contact are only exerting down pressure on the stems and never side stem pressure.  Rotate the cam if necessary during the torque down sequence to guarantee no pressure is applied to the side of the valve stem.  Rubber bands are an aid toward success.

[wally550k0]

So what is your method for torquing the cover? if it's unavoidable what are the steps? I'm in the midst of a rebuild and have heard this caution several times.

To the OP. that shaft wear is nuts! my 550 has similar milage to yours and I also have the old style cover. My rocker shafts are all centre and I don't have any cap connection. I wonder why this would vary bike to bike?

This is what I have going on ATM

Yes, it's pretty extreme considering the mileage but easily explainable.  "Tolerance stackup" if you've ever heard the term.  Imagine a tight clearance between the rocker and shaft and a loose one between the shaft and shaft bore.  Rotation of the shaft in the bore is the path of least resistance.  Of the eight valves that one was the worst; two others had started down the same path.  I'm just glad I caught it now.

[wally550k0]

So what is your method for torquing the cover? if it's unavoidable what are the steps?

It is sort of a torque a little and test for contact.  Loose rockers and backed out adjusters are no threat.  Snug the bolts and find the rockers making valve stem contact.  Be damn certain the ones in contact are only exerting down pressure on the stems and never side stem pressure.  Rotate the cam if necessary during the torque down sequence to guarantee no pressure is applied to the side of the valve stem.  Rubber bands are an aid toward success.

I centered it at first the best I could and worked it down turning each bolt a half turn at a time and working side to side.  Once you're on the alignment dowels and nothing is binding you're home free.  I "practiced" it three times last night due to forgetfulness and fatigue.  Went on without a hitch every time.

[TwoTired]

Torquing the bolts evenly is not the issue.  Nor is alignment with the dowel alignment pins. If you didn't pay attention to warning below.  You'll have bigger issues that a worn cover.  Namely, bent valves and cracked valve guides.  Pushing down on the cover as the bolts tighten bends the valve stem.