4.1 Cam Bearing Installed Correct?

[getchasum]

I wanted to get some thoughts on my 4.1 production block build. I got to looking at the front cam bearing a little closer last night and started to question the way the bearings are installed.

Here's what I can tell you.........I know I have ACL grooved cam bearings (grooved on backside), I'm not sure if they have one or two groves on the backside but I was told they were grooved. Here's the deal that concerns me, the front bearing only has one oil passage drilled in it & it's at the 8/9 o-clock position. I will be using a flat tappet cam & it also has a groove in the front cam journal. Would you feel good about running it like that? I know most front cam bearings has two oil passages, one at 8 o-clock & one at 3 o-clock. The guy that did my machine work wasn't a Buick man & if he would have just installed the HD Dura Bonds like I asked for I wouldn't be so up in the air, trying to figure out if I'm ok.

What do you all think.....

 

[Lee Thompson]

bearings

I wanted to get some thoughts on my 4.1 production block build. I got to looking at the front cam bearing a little closer last night and started to question the way the bearings are installed.

Here's what I can tell you.........I know I have ACL grooved cam bearings (grooved on backside), I'm not sure if they have one or two groves on the backside but I was told they were grooved. Here's the deal that concerns me, the front bearing only has one oil passage drilled in it & it's at the 8/9 o-clock position. I will be using a flat tappet cam & it also has a groove in the front cam journal. Would you feel good about running it like that? I know most front cam bearings has two oil passages, one at 8 o-clock & one at 3 o-clock. The guy that did my machine work wasn't a Buick man & if he would have just installed the HD Dura Bonds like I asked for I wouldn't be so up in the air, trying to figure out if I'm ok.

What do you all think.....

How far along are you in the assembly process? I sent a PM. Did you not get it? You could drill the other feed hole which I believe it around 2 o-clock.
.090-.100 will be more than big enough. Remove the drivers side rear 1/4 in. pipe plug--apply compressed air while drilling with grease on the drill bit. Or you could tie the 2 oil galley together @ the rear. Remove the 2 plugs--install 2 -1/4in.NPT by 3/16 flare 90 degree fittings pointing downward. Hand bend 3/16 in. premade brake line (12 in. is long enough). Or just install another bearing. On second thought assemble and prelube--if no oil to drivers side then tie together @ rear. Best of luck.

 

[getchasum]

Thanks for the advise Lee, I think at this point I'll just order new cam bearing from TA and take it to a different shop to have them installed. The current bearings maybe ok since they are groved on the backside, I just don't feel good about only having one oil passage. On second thought I have quit a few new original GM cam bearings (pt#1234441) I picked up from a closing race shop...not sure if they are for if the older or newer blocks, I'll have to research or mabybe someone will chime in on this thread. I remember reading there is some difference in the cam bearing requiremnets for the older blocks to the 86/87 blocks.


For some reason I did not get the pm. There has been troubles on the board with pm's...I guess that what happened to it.