Cam chain replacement info?

[oldnortonrider]

10-4 on the "reminders" in the above, Tod; bringing back fond memories of when I'd done this~Sept.99. 33,000 miles on that chain~the one that's being replaced. Going thru this "drill, practice, rehearse", in my mind and on this forum so end result
will be without additional surprises. Gathering up the right shims
for the 3 intakes caught me by surprise. All 4 exhausts were still almost the same; no.1 went from 7-8~no.2 stayed the same @ .007~no.3 went from 8-9~no.4 went from 6-8 (thousandths).

NEXT PARAGRAPH: those camcap studs and nuts~~when the threads get "messed up"~~it's because they're being taken loose
and/or bolted/torqued back down with the camlobe on the "downside, having to depress two of the shim buckets, pushing hard against two valve springs. ?Theory~~I was thinking this task would go a whole lot more "sanitary", if two of
those valve shim/bucket depressor/tools were used to hold down
on the two buckets with the two camlobes pushing on them~~torque reading on (??) the camcap nuts would probably even be different? I never did acquire any of the shim depressor tools, cuz I was hearing that most often, the tool didn't work~wasn't made right. Read it a lot on this forum. That "Motion Pro" made the tool, and couldn't or wouldn't make it proper. I don't know if it would work, but seems like some mention would have appeared somewhere, about this having been tried by somebody. No matter how clever, and patient one
would be to torque down those 5 caps in the smoothest, most
gradual torque sequence~~one knows that cam is in a "wrong kind of bind" when it's being snugged down.

?Whaddayathink?

[trbig]

When the cams are on the timing dots, the exhaust has very little pressure on it. I install the intake first though for some reason?? The intake will not be exactly on the timing mark at first.. it wants to twist slightly towards the back of the motor. So let it.. Start the first 3 caps finger tight, then turn with the 10mm socket @ a full turn each progressing towrds the center (3RD) cap. After just a few times of this, the other two will be able to be started. Just

I have taken my cams off more times than I can count... at least a dozen times in the past couple years. As long as you don't try to torque them down and compress the valves from the end caps, (#1 & #5) you'll be fine. I haven't stripped any of the studs or nuts doing it this way. After you get them all torqued... against popular consensus I'm sure, I re-torque them again just in case torquing one side loosened up another. It would be catastrophic to a motor for just one of those little nuts or washers to be banging around in there. After torquing, turn the cams back on time.


Tod

[oldnortonrider]

Yes! THAT'S the kind of info, that I'm lookin' for. I remember, the
valve spring pressure trying to turn the dot "off".

I really appreciate your posting(s), on this.

[skids]

I have found on at least two of those xs11 cam chaiin jobs, that the dots on the cams are a "smidgon" wider than the arrows of the cam bosses when finished and at TDC.

Originally posted by oldnortonrider
Yes! THAT'S the kind of info, that I'm lookin' for. I remember, the
valve spring pressure trying to turn the dot "off".

I really appreciate your posting(s), on this.

[geniusloerts]

Timing chain

I am sure glad there are so many people who have done the chain swap, i am getting ready to do mine within the next few weeks

[trbig]

Just make sure to check everything 3 times before you move anything (Turning over the engine at all) The first time I ever did this, I thought everything was correct and timed. You spin the crank around twice to make sure the cams are in time with the crank still when you're done. So I put the wrench on it and watched the crank go around twice without ever looking up at the cams... they weren't moving. The chain was not on the crank sprocket... just riding beside it. So my first effort resulted in several bent valves. It's so easy to do it.. I never felt anything hit or felt any resistance. So just be careful.


Tod

[oldnortonrider]

skids~~if the dots are a "smidgeon" off with a new chain, could
pretty well used/worn cam sprockets maybe be the reason? I would imagine with the new chain, even if the dots were off a small bit, it probably ran much improved from the old chain...(?)
When I replaced the old chain 8 years ago, that I'm doing again now~~the dots were spot on with the new chain. A bunch off with the worn chain, before removal.
The 79 that I have with 23,000 miles, I have never run it since I got it. But figured the engine was in very good condition from it's appearance. I pulled the cam cover just to "see" how stretched the cam chain might be. Cam dots were spot-on.

trbig~~that had to have been the first one you did (?) Boy, that gives me the shivers just to hear about it. Nightmare experience.

[trbig]

Yup... first time expensive mistake. Hopefully others can learn from it too... makes it not so expensive that way. If this info helps you out.. please send check or money order to...


Tod

[skids]

The sprockets did not look worn. It did not really run any better or worse with the new chain, It did get a little more adjustment with the cam adjuster though (I was almost out).

Originally posted by oldnortonrider
skids~~if the dots are a "smidgeon" off with a new chain, could
pretty well used/worn cam sprockets maybe be the reason? I would imagine with the new chain, even if the dots were off a small bit, it probably ran much improved from the old chain...(?)
(snip)

[oldnortonrider]

?...have a question here, > ...I've got the intake cam out, and the new (thinner) shims in the buckets for the three 0.00 clearance valves, and another thinner shim in, for the "0.003" clearance valve. Question:.....Trbig, anybody,~~I'm wondering if the cams
could both be put back with sprockets not having been taken loose? How much difficulty, that might be; I wouldn't want to have the cams all the way capped back down, to find out it's not the best way. If it's not too difficult, it would save a bit of work, not having to take the sprocket bolts loose, and then bolting them back. Last time, I had sprockets already undone, before I even thought there might be a better alternative method.

2nd question: > wondering which way safest and easier to hook new chain together and brad rivet link, after cams and sprockets are in place; or better to hook it together before cams are poked through the newly bradded loop of new chain. ?

[trbig]

I can't give you a definitive answer on either, but it seems I have tried to put the chain on the sprockets and it would go with the cams loose, but that you couldn't get the chain up on the shoulders of the cams until they were tightened down? It's been a while since I tried, but I think that's the case. Either that or I couldn't get both cams to drop down into the grooves to put the caps on?? I think your chances of just plopping the chain on the sprockets and trying to install them and having them actually be in time are slim even if it did work.

Just me personally, I would get the chain joined first to give yourself all the slack and room you need since the cams are already out. Just be careful and don't drop it down into the motor. If it does, there's ways to get it back with a telescoping magnet. But if part/all of the master link droppped... off comes the oil pan.

This step is going to be purely your personal choice though.


Tod

[oldnortonrider]

I think your thinking on that is pretty much the same as mine, or, that is mine is pretty much the same as yours~~regarding the danger of dropping anything in the channel. You can't really plug up the sprocket channels down into the motor, if channel has to be completely "unplugged", and trying to still attach the chain together. You can completely plug all the channels, with sprocket and cams completely out; attach and brad the chain without worry about dropping a link plate or even part of the rivet tool into the chain channel. Things have to be "plugged" and "unplugged" a few times, while setting the cams through the bradded loop, and getting everything lined up. Would not want a sprocket bolt to jump outta my fingers to find its way to "you know where". I appreciate yer input on this and your "moral support".

[skids]

1: I dont believe there is any other way.

2: Get help. Use a heavy but narrow bar with a flat end for one end, and for the other end, start with a center punch to slightly mushroom the rivots, then finish by peening the ends. At least, that is how I did it.

Originally posted by oldnortonrider
Question:.....Trbig, anybody,~~I'm wondering if the cams
could both be put back with sprockets not having been taken loose?




2nd question: > wondering which way safest and easier to hook new chain together and brad rivet link, after cams and sprockets are in place; or better to hook it together before cams are poked through the newly bradded loop of new chain. ?

[oldnortonrider]

That was the "next" thing I was going to bring up about this job; the Motion Pro chain rivet/cut tool, in my opinion, needed maybe 2-3 more little pieces, that could be switched around to do the "mushroom", "indenting", and/or "final bradding (squashing", of the pin. It's inadequate. I'm going to try to make something from a drill bit, or a nail, that would actually start the "mushroom"
to end of pin, before going on to "the bradding stage". To use with the Motion Pro tool. I was lucky last time, using nothing but this tool, getting the job done, and not wrecking the chain.

[trbig]

With all the time and effort you have so far, I'd just spend a couple more bucks and get a center punch. But again... that's just an opinion.



Tod