The factory cam timing sprocket has a flat machined surface on the back. The new one has a roller bearing. What is the purpose of this? Does it ride on the cam retainer plate? Is it called the thrust bearing?

Did you order the correct one for your application?

When installed, does it fit parallel to the crank gear so that the chain won't run at an angle? You can use a straight-edge to check.

The only roller bearing I've used over the years is a three piece Torrington bearing setup for retro-fit HRs. In addition to the roller bearing, it comes with two flat spacers/washers. So mine doesn't seem like yours.

How about posting the brand and part number of what you have.

Jake

This is the surface I was refering to. O.E. is machined, Jegs 9 key timing chain set has two configuations, roller bearing set, and bronze thrust washer set, (both for 87-92 sbc w/fac. roller cam). I purchased and installed the roller bearing set. Is the roller bearing an upgrade? It should be, as it cost an extra $21. It runs perfectly so far. What is the difference? Does the bearing make contact with the cam retainer plate? Did I make an oopsy? Thanks.

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I changed heads, cam, rockers and T/C set on my son's 96 LT1 this past summer but I went with a GM replacement timing chain set, so I don't know about the one you installed.

Hopefully someone else will chime in with the specific information you need. So consider this a bump.

Sorry I couldn't help more.

Jake

Found my answer on an old thread at Hotrodders. "Question on torrington roller bearing timing chain set".
350 with OEM roller cam.
"The thrust loads aren't so great that they need rocket science solutions to what is otherwise a simple problem. All your're trying to do is stop cam walk without gouging the block, with a thrust plate it's taking all, or most of those moments, so there isn't much for the timing gear or it's thrust washer to do in that regard".
Sounds like the O.E. arrangement is perfectly adequate. The bearing is overkill. If I was going to do it over ,I would probably order the less expensive model without the roller bearing. Also, there are rumors of failure of the bearing. Could be one of those web myths as I saw no first hand reports.

The roller bearing sprocket would be of more benefit on a 'retro' roller app. where the block does not have the cam retainer/thrust plate. Also needed is the 'button' that rides aginst the timing cover, but that is another topic.

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I did a few retro-fit swaps, on both BBs and one SB and on each I used the 3-piece Torrington bearing set without any issue. I always used the roller thrust button to control foward movement of the cam as opposed to the solid, aluminum types.

However, I did read one post about the possibility of bearing failure but it didn't have much detail and I don't know if it was a Torrington or one like you have. In all the reading I've done over the years, I've never come across any posts on failures, so I don't worry about that.

One thing I did read about was because the guy used the wrong retainer bolts which had thicker/taller heads on the bolts which interfered with the backside of the cam gear. Because of the difference in the heads of the bolts, they stuck out farther.

Only other things I can think of are: Failure to lube the new chain after installing it and failure to fully install the crank gear which caused the chain to run at an angle.

Jake

I did have to do some clearance grinding on the bolt heads and block for the new thicker double roller gear. Thanks for the feedback, Joe.