LS & LT Cam Bearings

[donjetman]

https://www.lsxmag.com/tech-stories...diving-into-gm-ls-and-lt-series-cam-bearings/

 

[j91z28d1]

good to see some of the internet theory that they align honed after installed the reason they all look bad being true.

still seems odd that if you replace the bearings you don't need to align hone again thou. but whatever works.

don't look and send it haha.

 

[SpareParts]

I changed out the original cam bearings in my spare engine. The #2 was shot for sure and the rest looked pretty worn.
I installed the CH25 bearings and they sure appear to be a superior part. Longer and 1 solid piece.
Because of the way GM stack bearings are made the block ends up with a gouge on all 5 bearing positions.
If you don't smooth that gouge out a little the bearings will not work properly and cause a tight spot when inserting the cam.
I had to replace the #4 twice to get it right.

 

[strutaeng]

Yup, I've installed those Durabond CH-25 bearings on the few Gen III LS engines I've rebuilt. Although I didn't have to ream the cam holes edges.

I bought the dedicated Summit Racing cam bearing installer. Works very well. First time took about 45 minutes, but second time took maybe 15 minutes at the most. Just put a sharpie mark on the edge of the bearing to make sure they are "clocked" correctly for the oil passage slot on the block. Easy peasy.

Those were the cam bearings from my 06 Suburban LQ4 @ 260k FWIW.

 

[SpareParts]

That is exactly what i did.
I installed then with the crank and rods still in the block. After install, i used a wire to poke through the oil holes to make sure the oil holes were lined up.

 

[SpareParts]

Here is a shot of my bearings. The #2 was horrible. Probably had a .010 ridge between where the cam runs and the center section.
You can also see where the bearing is joined and causes the gouge. Wonder if GM did that on purpose to help stop them from spinning?
Engine has 175K if i remember right.