Do the oil holes on the camshaft bearings all point to the top of the block? Or are some of them off-set? I think the machine shop goofed, because the middle 3 bearings are don't have the oil holes pointing to the top like the outer ones do.

Do the oil holes on the camshaft bearings all point to the top of the block? Or are some of them off-set? I think the machine shop goofed, because the middle 3 bearings are don't have the oil holes pointing to the top like the outer ones do.

If it is a small block it doesnt matter, they have a full annular groove in the block under the brg. Big Blocks have to be lined up.
I personaly line up the holes.

If it is a small block it doesnt matter, they have a full annular groove in the block under the brg. Big Blocks have to be lined up.
I personaly line up the holes.

It is a small block. Thanks - I didn't remember that about the grooves :)

I personaly line up the holes.

RS,

That actually is not the correct way to install them in a small block. Here is a bulletin from the DuraBond cam bearing catalog:


Maximum camshaft support will be realized by installing the cam bearing oil feed hole to the optimum clock location. Blocks and heads using a 360° oil groove located behind the bearing oil feed, allow one to move the clock position of the cam bearing oil feed hole. This way you can adjust the clock position during cam bearing installation to make sure that the optimum location for the best hydrodynamic wedge is selected. Locating and installing the cam bearing to take advantage of this hydrodynamic wedge will supply the maximum support for the camshaft during engine operation. The direction of camshaft rotation and the engine oil entry point into the bearing control the placement of the hydrodynamic wedge.

Note: If the oil feed passage in the block or head is just a hole without a 360° groove, the bearing oil hole must line up with the oil feed passage in the block or head. In some instances, the bearing oil feed hole in the cam bearing also lines up with a groove cut in the camshaft journal. In those instances, the location of the bearing oil feed hole in the bearing is also very critical fore and aft and may not match up 100% with the hole in the block or head.

The illustration in Figure 1 below shows the optimum engine oil feed hole location for a camshaft that is turning clockwise as viewed from the front of the engine.

Note: If the camshaft being used is driven with a gear-to-gear arrangement, or is a reverse rotation engine with a chain drive, the cam bearing oil feed hole will require repositioning to the opposite lower side. This is due to the fact that the camshaft is turning in the opposite direction as noted above.

Here is a quote from the Clevite bearing tech pages:
By the way, they are describing it with the block in its normal, upright position.

"On blocks without grooves behind the cam bearings, care must be taken to insure that oil holes line up between the bearings and block. Where the block has a groove behind the bearing, the bearing should be installed with the oil hole at the 2 o'clock position when viewed from the front for normal clockwise camshaft rotation. This will introduce oil into the clearance space outside of the loaded area and allow shaft
rotation to build an oil film ahead of the load."

Here is a link to the Clevite Web site...lots of interesting info: http://www.clevite77.com/Motorhead/t...f/cambrgs.html (http://www.clevite77.com/Motorhead/techstuff/cambrgs.html)

Hope this helps. :thumbsup:

Thanks for that Bill, This is Good Advice, You are indeed a wealth of Good information.

Yes I have seen this before and I even put them this way on Race Type applications with lots of valve spring pressure. It stops smearing? at the oil hole area. I also use the coated brgs. As far as a stock SB goes It probably makes no difference, I am sure there are a few million SB,s with the holes lined up? LOL.

Interesting info - thanks guys !