Cam Bearing Orientation

busterrm

solid fixture here in the forum
image.jpg
I am helping a friend rebuild his SBC and we are going to put in cam bearings. Just got block back from vatting and this is what cam tunnel looks like, do we need to still clock the bearing with the oil holes or does that little channel machined into the block negate that?
 
I got this Bob.

#1 is the front, #5 is the rear. Block orientated as it would be in the car.
The front cam bearing has 2 holes.

The best placement is 1) 10 & 2 o’clock, and 2 to 3 o’clock for the rest.
GM factory placement is 1) 1 & 5 o’clock, 2,3 & 4) 5 o’clock, 5) 12 o’clock

By placing the bearing's oil hole at roughly the 2:00 position (anywhere between 2:00 and 3:00 is fine), oil is fed into the clearance between the cam journal and cam bearing as the cam rotates clockwise, creating an oil wedge that travels down and supports the cam much better during cam rotation. This forces a superior oil wedge under the cam, to provide oil support at the bottom (6:00) position.

On engine blocks that do not feature an oiling groove on the bearing bores, it is vital that each cam bearing is installed in the correct clock-position, so that the bearing's oil hole accurately aligns with the cam bore oiling hole. If the cam bore features a groove, the bearing should be installed with its oiling hole placed at the 2:00 position (when viewed from the front of the block that features clockwise rotation).
 
be aware the oil feed is from the lifter gallery area,and not all blocks have grooves on any bearing locations other than #1 and #5 ,
look at the link, too the thread below and its pictures carefully
so you will need to line up any oil feed holes,in the bearings to the lower main bearings, to get oil feed.
many cam bearings come numbered (they are not randomly interchangeable)and most but not all sets, come with instructions

cam-bearing-guide.jpg

SBCOilingnew.png

http://garage.grumpysperformance.com/index.php?threads/cam-bearing-install-tools-install-info.1479/
 
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74833CB3-91AE-44CF-9414-87A864AFF0C3.jpeg Okay, this is my first time installing cam bearings, Love302Chevy- the #1 is the only bearing that has 2 oil feed holes in my set, so it clocks at 10 and 2 o’clock right? 2-5 clock at 2 o’clock right? All with the block in normal position as if it were in the car! I have them arranged in the box from front to back (1-5)! Just waiting on the bearing driver to get here! This block does have a groove in all 5 cam bearing journals
 
Correct. Except that any bearing bores WITHOUT a groove MUST have the oil aligned with the hole in the bore.
Which journal(s) do not have grooves? Pictures please.

With your bearing set, from front to back, you should have SH-290, 288, 287, 287, & 288 at the rear.
 
I still have to go through and scotch brite the block from the vatting . It sat all day Thur and Fri at machine shop so it has some flash rust. We are doing some casting flash clean up and opening up some of the oil feeds and rounding sharp edges. Once we get rot assembly and cam and timing set. I will check deck height then send it back to be bored and decked(if needed). Then we will clearance the block for the longer stroke. Clean it up real good and glyptal red paint the internals where needed! I do have a question, since the top of the lifter valley doesn’t have open holes like my DART block does it need screens? It does the holes under the top oil galley!
 
All grooved - go with your original plan.:thumbsup:
I would leave the lifter valley holes open, but JB Weld some magnets in the area instead.
However, Moroso does have a screen kit for those holes.
Have you successfully used Glyptal before in this application Bob? I tried it once on a new block that I did final cleaning in a heated tri-chlor vapor degreaser.
That stuff cleans into the pores of the cast iron. Anyways, after a short time running, the Glyptal started to come off. I ended up scraping it all out of the lifter valley - AND IT WAS NOT EASY! I use Rustoleum now - and it stays put.
 
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http://garage.grumpysperformance.com/index.php?threads/magnets.120/#post-49772

http://garage.grumpysperformance.com/index.php?threads/valve-train-shrapnel-screens.1458/#post-22845

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/#post-54398

use proper oil and filters and damn surely use high temp magnets to trap fine metallic abrasive crud
epoxy in place as ceramic magnets are brittle and can't be drilled
 
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Yes, I used it on my Dart block, I cleaned that block 3 times before then used acetone and final was alcohol. Then let it cook on in the 95-100 degree temp we had that summer for about 8 hours.
 
All grooved - go with your original plan.:thumbsup:
I would leave the lifter valley holes open, but JB Weld some magnets in the area instead.
However, Moroso does have a screen kit for those holes.
Have you successfully used Glyptal before in this application Bob? I tried it once on a new block that I did final cleaning in a heated tri-chlor vapor degreaser.
That stuff cleans into the pores of the cast iron. Anyways, after a short time running, the Glyptal started to come off. I ended up scraping it all out of the lifter valley - AND IT WAS NOT EASY! I use Rustoleum now - and it stays put.
I really have not found any bad products or advice from Grumpy thus far Mike.
Those 1957-64 Pontiac Olds Read diffs I like when I tear one down the inside center hogs head still has GE Glyptal intact.
Everyone of them was painted with Glyptal.
Been other complaints similar.
Maybe another brand was used I don't know.
 
Correct. Except that any bearing bores WITHOUT a groove MUST have the oil aligned with the hole in the bore.
Which journal(s) do not have grooves? Pictures please.

With your bearing set, from front to back, you should have SH-290, 288, 287, 287, & 288 at the rear.
Exactly Mike, when you said that I checked it and labeled the box.image.jpg
 
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