Small Block cam bearings

[Steve D.]

Cam bearing journals #1,2,3,4 all have oil holes at top and bottom, 180 degrees apart. #5 has 3 holes at the top spaced about 20? degrees apart. When I removed the bearings, I noticed that #2,3,4,5 all had 1 hole each. #1 had 2 holes about 110 degrees apart. When installing new bearings, I assume the holes in the bearings should be aligned with the holes in the journals. Since there is not a unique hole-to-hole position, what is the "right" way to place the bearings ?

Steve

[Joe L.]

Re: Small Block cam bearings

Steve-----

The indexation between the cam bearing and the cam bearing journal is a non-issue; they can be installed in any relative position. The one exception is the rear journal on 55-56 265 cid small blocks, but I assume you aren't talking about one of those.

However, you should have THREE different size cam bearings, all just slightly different in OD. The front bearing (#1) is unique. The #2 and #5 bearings are the same and the #3 and #4 are the same. Different cam bearing manufacturers mark them differently, but they should be marked in some way.

[Clem Z.]

Re: Small Block cam bearings

the oil hole in the bearing should be at the 5 oclock position facing the block from the front with the block right side up. this put the incoming oil at the highest load point on the bearings because of the cam rotation and never put them at the 6 oclock position because this way the oil hole is shut off by the downward pressure of the cam. the front bearing has the 2 holes to allow more oil for the cam gear and chain and i would split the difference with the 2 holes on equal side of the oil hole in the block going to the mains. if you put the bearing oil hole at the top you will have a internal oil leak because of the clearance that could starve the mains. i know big blocks have the oil hole at 6 oclock but they oil the mains in a different way than a small block. this may not be too important with a stock cam and light springs but if you go with a cam that requires stiff springs i would do it this way to make sure you do not scuff the cam bearing journals from lack of oil

[Steve D.]

Re: Small Block cam bearings

Clem

Does the 5 o'clock position apply to the #5 bearing also ?

Steve

[Clem Z.]

Re: Small Block cam bearings

yes put it a 5 oclock because the grove has the holes to oil the lifters and the hole in the bearing oils the cam

[Steve D.]

Thanks *NM*