Cam bearings install
04-09-2015, 07:00 PM
#1
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Cam bearings install
One question I just got my block back from the machine shop the front bearing with the engine upright and looking at the front the one oil hole is at 6 0clock and other is 3 or 4ish they line up with oil holes in block my question is is this correct?
04-10-2015, 02:54 PM
#3
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Re: Cam bearings install
The factory manual says this:
#1 at 1 and 5 o-clock, #2, #3, #4 at 5 o-clock, #5 at 12 o-clock
The often referenced LT1 rebuild book recommendation is:
#1 at 2 and 10 o'clock and #s 2,3,4,5 at 2-3 o'clock.
The book's text says this helps create a good oil wedge for the cam to ride. It also says you don't want the hole in the bearing to line up with the block oil passage hole, because it might cause a momentary pressure feed-back that can prevent oil from traveling around the journal (the LT1 has full circumference grooves around the journal for oil flow to the bearing oiling hole and to the mains). They note that this also makes bearing position a little less critical.
Previous SBC blocks that did not have the full circle oil groove needed to have the oil holes aligned.
The front bearing is #1.
#1 at 1 and 5 o-clock, #2, #3, #4 at 5 o-clock, #5 at 12 o-clock
The often referenced LT1 rebuild book recommendation is:
#1 at 2 and 10 o'clock and #s 2,3,4,5 at 2-3 o'clock.
The book's text says this helps create a good oil wedge for the cam to ride. It also says you don't want the hole in the bearing to line up with the block oil passage hole, because it might cause a momentary pressure feed-back that can prevent oil from traveling around the journal (the LT1 has full circumference grooves around the journal for oil flow to the bearing oiling hole and to the mains). They note that this also makes bearing position a little less critical.
Previous SBC blocks that did not have the full circle oil groove needed to have the oil holes aligned.
The front bearing is #1.
04-10-2015, 04:33 PM
#4
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Join Date: Apr 2015
Posts: 24
Re: Cam bearings install
The factory manual says this:
#1 at 1 and 5 o-clock, #2, #3, #4 at 5 o-clock, #5 at 12 o-clock
The often referenced LT1 rebuild book recommendation is:
#1 at 2 and 10 o'clock and #s 2,3,4,5 at 2-3 o'clock.
The book's text says this helps create a good oil wedge for the cam to ride. It also says you don't want the hole in the bearing to line up with the block oil passage hole, because it might cause a momentary pressure feed-back that can prevent oil from traveling around the journal (the LT1 has full circumference grooves around the journal for oil flow to the bearing oiling hole and to the mains). They note that this also makes bearing position a little less critical.
Previous SBC blocks that did not have the full circle oil groove needed to have the oil holes aligned.
The front bearing is #1.
#1 at 1 and 5 o-clock, #2, #3, #4 at 5 o-clock, #5 at 12 o-clock
The often referenced LT1 rebuild book recommendation is:
#1 at 2 and 10 o'clock and #s 2,3,4,5 at 2-3 o'clock.
The book's text says this helps create a good oil wedge for the cam to ride. It also says you don't want the hole in the bearing to line up with the block oil passage hole, because it might cause a momentary pressure feed-back that can prevent oil from traveling around the journal (the LT1 has full circumference grooves around the journal for oil flow to the bearing oiling hole and to the mains). They note that this also makes bearing position a little less critical.
Previous SBC blocks that did not have the full circle oil groove needed to have the oil holes aligned.
The front bearing is #1.
04-10-2015, 09:56 PM
#5
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Location: Kernersville, NC
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Re: Cam bearings install
Below is an old thread when I was learning how to install cam bearings. There is a link to Dura-Bonds website(in the first post) that has a PDF worth taking with you. Notice the "best" at 2 o'clock in that PDF.
https://www.camaroz28.com/forums/lt1...arings-749300/
If I recall my final clocking positions, I went 10 and 2 o'clock on #1, then 2 o'clock on all the rest.
If the 2-5 bearing holes are at 3 o'clock, then we might be splitting hairs on asking them to change them....but for sure get the #1 bearing fixed.
Last edited by ACE1252; 04-10-2015 at 10:17 PM.
04-10-2015, 10:00 PM
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04-12-2015, 08:32 AM
#7
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Re: Cam bearings install
Yes.
Below is an old thread when I was learning how to install cam bearings. There is a link to Dura-Bonds website(in the first post) that has a PDF worth taking with you. Notice the "best" at 2 o'clock in that PDF.
https://www.camaroz28.com/forums/lt1...arings-749300/
If I recall my final clocking positions, I went 10 and 2 o'clock on #1, then 2 o'clock on all the rest.
If the 2-5 bearing holes are at 3 o'clock, then we might be splitting hairs on asking them to change them....but for sure get the #1 bearing fixed.
Below is an old thread when I was learning how to install cam bearings. There is a link to Dura-Bonds website(in the first post) that has a PDF worth taking with you. Notice the "best" at 2 o'clock in that PDF.
https://www.camaroz28.com/forums/lt1...arings-749300/
If I recall my final clocking positions, I went 10 and 2 o'clock on #1, then 2 o'clock on all the rest.
If the 2-5 bearing holes are at 3 o'clock, then we might be splitting hairs on asking them to change them....but for sure get the #1 bearing fixed.
04-13-2015, 09:16 PM
#9
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Location: Kernersville, NC
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Re: Cam bearings install
The only one close to right is #5. Bearings 1-4 MUST be re-clocked. #5 will live, but I'd have it put at between 2 and 3 o'clock as well.
I would put them like the LT1/4 rebuild books states....and in fact is what I did on mine.
I would put them like the LT1/4 rebuild books states....and in fact is what I did on mine.
Last edited by ACE1252; 04-13-2015 at 09:23 PM.
04-13-2015, 09:44 PM
#10
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Re: Cam bearings install
When I was faced with this, I think that is what I did, too (been a while).
04-16-2015, 08:14 PM
#12
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Re: Cam bearings install
Many "Performance engine building" books have been written which state that the cam bearing should have it's hole lined up with the feed bore for the main bearing....literally millions of motors have been built this way and suffer no ill effects. Now obviously we know that's actually not the ideal position, but the reality of the situation is that 99% of motors will be just fine no matter where the hole on the bearing ends up being clocked. In fact it might blow your mind to know that most aftermarket blocks and most engines that are not a Chevy small block or big block don't have an annulus cut into the block and so the bearing must be installed with the oiling hole at 6 o'clock...they don't lock up the cam and explode because the oil wedge was not ideal.
Personally I clock them at about 3 o'clock on the Chevys because I don't want to change my procedure from street engine to high spring pressure race engine, it's just simpler that way.
What makes a bigger difference is using a CHP-8T coated bearing, we get double the hour life out of those in our solid roller race engines....I can say that because I've run them all the different ways possible.
Personally I clock them at about 3 o'clock on the Chevys because I don't want to change my procedure from street engine to high spring pressure race engine, it's just simpler that way.
What makes a bigger difference is using a CHP-8T coated bearing, we get double the hour life out of those in our solid roller race engines....I can say that because I've run them all the different ways possible.
04-17-2015, 10:22 AM
#13
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Join Date: Apr 2015
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Re: Cam bearings install
Many "Performance engine building" books have been written which state that the cam bearing should have it's hole lined up with the feed bore for the main bearing....literally millions of motors have been built this way and suffer no ill effects. Now obviously we know that's actually not the ideal position, but the reality of the situation is that 99% of motors will be just fine no matter where the hole on the bearing ends up being clocked. In fact it might blow your mind to know that most aftermarket blocks and most engines that are not a Chevy small block or big block don't have an annulus cut into the block and so the bearing must be installed with the oiling hole at 6 o'clock...they don't lock up the cam and explode because the oil wedge was not ideal.
Personally I clock them at about 3 o'clock on the Chevys because I don't want to change my procedure from street engine to high spring pressure race engine, it's just simpler that way.
What makes a bigger difference is using a CHP-8T coated bearing, we get double the hour life out of those in our solid roller race engines....I can say that because I've run them all the different ways possible.
Personally I clock them at about 3 o'clock on the Chevys because I don't want to change my procedure from street engine to high spring pressure race engine, it's just simpler that way.
What makes a bigger difference is using a CHP-8T coated bearing, we get double the hour life out of those in our solid roller race engines....I can say that because I've run them all the different ways possible.
04-17-2015, 11:05 AM
#14
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Location: Little Rock, AR
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