107M bearings

[gofstbuick]

I Just began checking bearing clearances. I noticed something odd on the lower shell of the main bearings. The 107M bearings are 3/4 grooved. Next the grooves on one side of the bearing is an indentation (or cut into) the face of the main bearings. Sort of looks like a chewed up bearing tang on the face of the bearing. This is only on the lower shell, on one side and this indentation is not on the thrust main bearing. The upper shell has the oil groove on the face only, but no matching indentation for the face of the lower shell. Does anyone know what that indentation is for. Federal Mogul is under the impression that I have encountered a mis-boxed item (even though Merkel claims 3/4 grooved main bearings would soon be available). The bearings spec okay, I'm just concerned about the indentation on the lower bearing face.

 

[Intercooler]

Can you post a picture? I have used the 3/4" groove main bearings before but don't know what yours look like. You sure isn't on the thrust sides?

 

[gofstbuick]

yes, I'm sure about the thrust bearing shells. The indentations are on all the lower shells except the thrust shell. I'll see if I can take some pictures tonight. Federal Mogul indicated that as of this date, the 107M main bearings are only available with 1/2 oil groove (the upper shell is grooved). I need to get the number off the back of the shell and provide it to FM to determine if it is a mis-boxed item.

 

[MSDGN]

Pics will be good...I have a set of 107M's at home that I'm getting ready to put into my new motor...

 

[gofstbuick]

Are your 107M bearings 3/4 grooved? If so, look at the lower bearing shell only (this is the shell with the partial groove, not the one with the oil feed hole). Next to one of the oil grooves (same side of the bearing that the tang is on) will be two short indentations on the bearing face. It kind of looks like to mini oil grooves at the mating serface (no more than 3/16 of an inch in length) that are parallel to the main caps (oil groove).

 

[MSDGN]

Haven't looked at them in awhile so not sure about 1/2 or 3/4 grooved...will look at them tonight...

 

[gofstbuick]

Actually I'm mistaken, the little notch is next to the oil groove on the upper shell, not the lower shell

 

[Intercooler]

Pretty sure that is normal.

 

[gofstbuick]

Yup, pretty normal, it's the press point for the bearing tang

 

[MSDGN]

Checked my 107M's...the lower bearing has no groove...

 

[gofstbuick]

According to the Federal Mogul site, the 107M bearing set is a 3/4 groove set. I read previously the set was 1/2 groove and the most recent update is a 3/4 groove bearing. Merkel alluded to this fact in his engine buildup article in (GMHTP). I don't know if your bearing set provided block positions for the bearings, but my set did not have the block position instructions. I figured the positions out on my own. The Federal Mogul website provides the position information. Look at the part number on the balck of the bearing. 7117CH (U is upper and L is lower) fits position #2; 7116CH is for positions 1 and 3; 7118CH is for position 4.

 

[MSDGN]

Nope didn't have block positions but it would be pretty hard to screw the positions up...thrust is obvious...#1 and #3 are the same...#4 tang position is different...I believe those numbers jive with mine...I know #1/#3 are 7116CH...I remember that from looking last night...I've had my set for about 6 months but I don't know how long the person I got them from had them...