If they are not supposed to contact each other, what keeps the cam from walking forward or backward is what I can't figure out as the retainer is the only thing stationary to the block with either the cam nose edge on one side or the sprocket face surface on the other side to contact it to keep the cam in position and not walk back and wear/push out the rear plug or walk forward out of the block.
I realize you don't want to sandwich the retainer plate but there should be .004 to .012 play around it. What am I missing here?

And why would there be excessive wear in Sweet's case? maybe the retainer is too think or the cam nose past the stepped edge is not long enough?

 

I know the pictures are sh!tty, but my cam potrudes about 3/16" - 1/4" from the retainer. The timing set itself has about 10,000 miles on it and it has less than 1,000 miles with this particular cam. I have not had any noise from the front of the motor. Is the cam supposed to stick out farther than what it does? What could possibly be causing the rubbing? It seems like it's done all the wearing it's going to do, so I've stuck it back together for now. I'm moving in less than a month, and I definitely don't have time to dig into this. I am looking for suggestions though. Sorry for high-jacking your thread 2QUIK6.

 

If you look on the back of the cam sprocket for the ED set, you'll notice the the part where the nose of the cam mounts in the sprocket is recessed, so in order for the sprocket not to contact the retainer, the cam must protrude out further than that recessed part is deep..follow me.

There is nothing holding the cam from walking forward or backward except for the retainer with the cam nose recessed edge on one side and the sprocket back on the other, its going to contact just like push rods on guide plates. I think some grinds tend to drive the cam more in one direction so there's going to be more wear in one direction.

If there's not metal flakes/glitter in the oil I'm not going to worry about mine, but will make sure the cam retainer is not sandwiched tightly behind the gear. This rebuild book that is supposed to be so thoruough mentions nothing about checking this.

 

Cam snout should protrude out of the cam plate. I have no exact measurements as to how much. The cam is secured from the rear by the oil pump drive gear and the cam plate keeps the cam from walking forward. I have no idea why there would be wear in the other case.

 

I have no clue what is causing it either. I have no clue if the lobes are bad, the bearings are brand new (I know that doesn't mean anything), and the lifters are Crane OEM replacements in which I haven't noticed anything unusual (collapsing, noise, etc). I wonder if my wobbly water pump gear could have aided in the movement of the cam shaft. I'm at a loss for now. Like I said, it needs to go back together, and I'll try to tackle this some day down the road. Thanks for everyone's help.

 

Sorry to dig up such an old thread, but I ran into the same issue when I installed my LT4 hd timing set. Gear noise from the opti/timing cover after the engine heats up. It about drove me crazy trying to figure out what was going on. After some experimentation, I think I know what is up here. It has to do with the fit between the GM opti and the LT4 timing set. A while back I replaced my GM opti with a $149 ebay opti (until it died a week later ) and the gear noise was gone . After the ebay pos died, I put a GM unit back in and the gear noise returned. I suppose that the GM opti may have too thick a drive or the drive is recessed to the back too far and is pressing against the timing gear. Sooo I ordered some 0.005" shims from Mcmaster Carr to place behind the opti bolts so I can shim the opti out a few thousandths. I haven't placed the shims in yet and I'll keep you posted when I do. This sound reasonable?

 

Very well may work, since this post started, I have switch cams, and at idle it sounds like plastic scrapping against plastic. Immediately off idle it stops. I have heard 3 other folks cars with the LT4 HD set, and it sounds similar, so I just have grown to ignore it now. When I did the cam swap, with about 10k miles on the old one, I noticed no abnormal wear.

 

I found this thread while searching for info on my similar problem, posted here:
https://www.camaroz28.com/forums/sho...d.php?t=713220

I have the same noise you and Vince seemed to be describing.
I have a cloyes true roller timing set, which appears to be the same design as the lt4 ed set. So after tearing everything down and rebuilding it, you never solved the noise? The retainer plate bolts weren't the culprit?

I'm going to put a 10W40 in the motor next, been running 10W30 to seat the rings and such... maybe it will quiet it some. Man I hate stuff like this.

 

Here was the solution for the problem, I thought I had updated it here back then but I guess not.
https://www.camaroz28.com/forums/sho...d.php?t=595253