Cam Timing Question

[walt]

Spent most of the afternoon trying to time the left cam on an 82SC. How do you prevent the indicator from moving when the pin is removed from the sprocket just prior to rotating the crankshaft pulley back to the "Z" position. Each time I removed it, the indicator would jump about .010 -.015 in. The pin is a little difficult to remove indicating some tension there. Also, I assume you should maintain constant load on the timing chain during the entire procedure.

Thanks.

[Rot 911]

Sounds like you may not have enough tension on the timing chains. Do you have Wayne's rebuild book. Does a good job of taking you through this task.

[kstylianos]

Yes, constant (and more importantly equal) load on the chains is a must.

The dial indicator moves when the pin is pulled because the rockers/springs are loading the cam lobes. To help prevent the cam from moving when pulling the pin, try installing all rockers and and set valve lash to zero (elephant foot touching valve stem). I tried just installing the rockers (inkate/exhaust) only on cylinders 1 and 4 and there is no way the cams would keep still. BTW: What type of cams are you using? Higher/faster lift cams will be harder to tame

[addictionMS]

try the high lift cam technique as well, if all else fails.

JIm

[ChrisBennet]

I just mark the initial pin hole (dots at top) with some yellow crayon so I know "where I am". Whne I move the pin, I rotate the cam until the rocker is unloaded and move the pin.
-Chris

[ANTONIO]

Loose all rockers,exept #1 & # 4 of course, you'll be ok.,Antonio.

[echrisconnor]

Chris B's approach is the easiest. Just move in single pinhole increments and you'll get there. Move pin, re-tighten, check. Repeat, repeat, repeat.