Topic: 22r rattle/knock & cam/rocker break-in

[nate650]

 well I developed a rattle that I can't pinpoint. I'm pulling the oil pan next oil change to check the rod bearings. If it is a rod bearing, can I just pull the caps and slip a new one in with a little Assembly lube? I also assume I would need to replace all 4 to keep everything balanced?
 My next question is, I'm planing on putting a new cam and rockers in and I run full synthetic 10w30. Is it OK to beak-in the cam/rockers on synthetic? using plenty of Assembly lube of course.
 Also, would it be better to use a cheap oil for break-in since I think your supposed to change it out after break-in to clean out the Assembly lube?
 Thanks in advance.
-Nate

[79coyotefrg]

yes  you can replace the bearings  that way

dont use synthetic  for breakin

just use some regular 10w-40  for breakin

[CTENG in KS]

Did you use a screwdriveroscope?

[DanS]

I'd try a hardwood dowel (1" dia.x12"long), transmitts sounds better without metallic pitch. Always replace bearings in sets, but be sure to measure crank journals and block bearing seats for excessive wear, they may need line bored and larger bearings. (problem I'm having now with my stroker block  )
Good luck, DanS

[emsvitil]

Are you sure it's not the timing chain ratteling against the cover?

The plastic guides go south regularly

[nate650 [OP]]

 Yeah, I tried the screwdriver/piece of vacuum line trick and I still can't determine the source. It sounds like the top end to me. I adjusted the valves and no change. I didn't see anything abnormal while I was in there either. it sounds too high pitched to be rod knock but sometimes on start up it dose knock until it builds oil pressure.
 
One thing tho, when you put a finger on each valve cover bolt, the front one on the intake side has a noticeable taping in it. It could just be feedback from the mec-fuel pump as it makes quite a bit of rattle on its own.
 
The engine has a fairly new rebuild with only 15k on it so it shouldn't be the chain or guides but I'll check anyway. The sound started when I was snow wheeling and was revving her pretty high.
 I've been wanting to put a slightly bigger cam in it so maybe I'll start there.