I think when you ordered all your stuff they gave you 06-up cam bearings and not the 00-06 ones

 

Now that's a very interesting thought...

EDIT: I just went through my pictures from the initial thread, and found this:

 

They have different Outside Diameters...one wouldn't replace the other


.

 

Right... The later ones are a couple of tenths larger, if I recall...

 

Oh. My bad. I always thought it was the other way around. Inside different.

 

Both...Inside is different also

 

Last night I was too tired to work on it, but hopefully tonight I'll be able to. I've been thinking of ordering new front and rear cam chains, just to rule things out... I actually think my secondary chain (on the back) has stretched a little bit, as the alignment marks aren't perfect when there is tension on it (but definitely less then half a tooth off).

Question: I see that Andrews makes a rear pulley for the primary cam chain that accommodates the cam position sensor and a late-style roller chain. Is this a worthwhile upgrade, assuming the secondary chain remains a (fresh) early-style silent chain, or is there really no reason not to just get two fresh OEM silent chains?



Also, if I do "upgrade," will I need anything beyond the chain, a pair of sprockets, and a shim set?

 

I messed around with it a bit yesterday. Thinking about everything that's new, and everything that I've ruled out, and the fact that the original inner tensioner was in MUCH worse shape than the outer, I started thinking again about preexisting items that may have something to do with this. Runout was really the only thing that came to mind. I checked runout during my initial build and found it to be .0025", which is more than I would like, but within the tolerance listed in my service manual of .0003". I checked it again yesterday to make sure that I was correct the first time, and that it hadn't gotten worse. Exactly .0025" again. Then I started wondering whether the point of maximum runout may by chance correspond with the point where the sound occurs, but I quickly ruled out that theory when I remembered that the sound will occur at the top of the lobe on either front lifter, which obviously occur at different points of crank rotation.

Next, I replaced both inner cam bearings with a fresh set (from the S&S cam installation kit - I had two). I also rechecked the alignment of the two outer cam sprockets. Everything checked out. Put it all together, installed and preloaded one pushrod, turned the engine... Same sound, same place.

To the best of my knowledge, I've ruled out the following now:

-Everything in the rockers
-Pushrods
-Lifters
-Inner cam bearings
-The crank
-Both tensioners
-The oil pump
-Pistons

This leaves the cams themselves, the cam plate, the chains and the sprockets, as far as I can determine.

I'm going to order a fresh set of silent chains from Boardtracker later today, unless someone can convince me that it's a good idea to convert the outer chain to a roller-style, in which case I may use the Andrews sprocket referenced above (although I don't really feel like experimenting at this point).

Also, does anyone more knowledgeable than I think that .0025" of runout could be part of my problem, despite being within the factory tolerance?

 

But wait, did you have the same amount of play when you put the cams into the new bearings? If so, and if the extra set of bearings came with the original kit you ordered that may have been the wrong inner diameter wouldn't you be better off ordering new bearings from scratch, or had you already ruled out the bearing diameter?

 

I don't know the answer to this, but didn't you already turn the cams with the front chain removed? That should eliminate runout as an issue.

And if it's the chains, you'd think the noise wouldn't happen at the same point in the rotation.

I'm not really familiar with the older style cam plates. Are your cams pressed into the front bearings? You replaced the inner bearings again, right?