I don't think you will find the bearing being bad. I installed 2 different optis on mine and the noise stayed the same before shimming it.

 

I plan to shim it as well. not sure how much to shim it. i used washer last time. 2 thou i think it was the were. might need some more?

 

Use the play-doe idea and determine how far it sits in there with no washers, then you'll know exactly how many washers to use to get the dowl at around half depth into the recess in the opti..it doesn't need much to turn the opti.
Coat the dowl with a few drops of oil before stabbing it into the play-doe so it doesn't stick to it.

 

Cool, thanks for the idea's I hope this will resolve the issue. now to find play doh

 

Forgot to ask, do you by chance have an LT4 HD timing chain? Don't really know why that would matter since the dowl deminsions would be the same sticking out.
Seems like that was a common thread when I found others with the issue..and btw, my LT4 truck has the same comp grind cam in it, but has a stock LT4 timing chain setup and it has never exhibited the noise issue.

 

GM Extreme-Duty Timing Chain Kit, LT1 & LT4 Engines
[12370835]

that's the timing chain that was installed during the rebuild. Not sure if that is the lt4 one or not

 

Is it possible the CKP reluctor is rubbing on the timing cover? You may not have a CKP, but I can't tell that because you don't indicate the year of your car/engine.

Why not add a "signature" with basic info about your car, so people can help you?

You aren't the only one with the problem in this thread who doesn't provide info about the year of the engine.

 

Sorry Injuneer, I guess that would have been some helpful information. I actually thought I had a signature, but i guess not. I have one now.

not sure what a CKP Reluctor is
But when listening with a stethoscope tonight when listening directly on the timing cover the sound was not there and it didnt sound like anything was rubbing in there. The only time the sound was overly loud and apparent was when I was on the opti.

 

Yeah thats it...I had some other issues early on related to that gear set, installer didn't use the wp gear that came with that set and had some noise issues with that and you could clearly see the gear teeth starting to wear prematurely (different noise than what yours is exhibiting) , GM sells 2 different wp gears for this very reason, one is a harder steel, the HD one should have 3 holes in it as opposed to 5 or 6 around the gear.

 

It wouldnt be the crank reluctor because my engine is doing the same thing and it doesnt have one ('95).

 

And you don't have a signature either, so how would anyone know?

Still can't understand the reluctance of so many to use the signature feature. Not only does it help people answer your questions, it helps people understand the info you provide when you try and help them. There are enough differences from year to year that it's essential info.

 

I have never heard of shimming the opti before. I assume you guys that have must have had the drive pin sticking out of the cam a tad more than optimal.

I have seen opti rotor buttons rub the inside of the opti but that does not sound like whats in the clip. I think something might be rubbing the timing cover and if thats the case, it will be easy to see once the cover is pulled and checked.

I cant see that being the opti bearing. If it were you would be able to "feel" it by spinning the opti by hand. If you replace the bearing, make damn sure you "clock" the 2 piece shaft back the way it presses apart or its headaches for sure. Ask me how I know.

Whenever I install a new opti, I chuck it up in a drill and try to listen for funky sounds and vibes by biasing the shaft both directions prior to install mainly for piece of mind.

 

It looks like my timing cover (area behind the opti seal) could be rubbing against the cam timing gear, which could definitely cause a noise like this.

Synchro, when you pull your opti off, look in the opti seal hole and see how close your timing gear is to the cover.

 

Unfortunately I did all of the work on my car last night, so i didn't get a chance to take a good look at that gap. it looked close from what I remember. I did measure everything else and the dowel is no where close from bottoming out on the opti. I still shimmed the opti. i also swapped the back plate on the opti with the old GM one I had. To rule out the bearing. I just took the car for a rip. Noise came back once it got hot. and the car is running like a$$ a idle. almost stalls when letting the clutch out. but once you moving there is lots of power there. have to check my opti connections.
So I don't know what to do next. My engine builder want the engine back to go through it.
Not looking forward to pulling it again.

 

I don't know how I missed this post. maybe that why it isn't running properly
at idle. But I never touched any of that stuff. I just put in the timing disk, sensor and cap/rotor to the old opti. The shaft and bearing and such I didnt touch. I would think that mean the shaft and all would be aligned still.