front cam journal grove?

[ryan319]

hi, i was just getting ready to swap a 210/215 comp roller cam in my 86 GN and hit a little snag. the flat tappet comp cam that came out had a grove machined in the front journal. however the new comp roller that's going in does not. the grove appears to feed the lifter galley.

should there be a groove machined in the front journal of the new roller?

i know that there is oil passage under the cam bearing in the 86/87 blocks. will i have sufficient oil flow with a regular cam bearing and no journal grove? should i just get a new cam bearing and go with it?

 

[Blown&Injected]

Mine is doing just fine. The oil makes its way in the groove in the block and ya get that much more effective bearing surface.

 

[A2000RICH]

hi, i was just getting ready to swap a 210/215 comp roller cam in my 86 GN and hit a little snag. the flat tappet comp cam that came out had a grove machined in the front journal. however the new comp roller that's going in does not. the grove appears to feed the lifter galley.

should there be a groove machined in the front journal of the new roller?

i know that there is oil passage under the cam bearing in the 86/87 blocks. will i have sufficient oil flow with a regular cam bearing and no journal grove? should i just get a new cam bearing and go with it?

some of the original GM cams had solid bearing surfaces and some were grooved------of all the original engines i have taken apart more have not had grooves than did------since the GN engine doesn't need the groove in the cam there must have been some other similar application where it was needed------- i sure can't see where it could do any harm either way in our engines..........RC

 

[getchasum]

Sounds like a Good Thing......

Pre 86 block were not grooved, so that groove in the cam was needed. The cam groove allows oil to reach the passage on the other side on older blocks. If your 86 block is groove between the oil passages (Under cam bearing), which it should be you are good to go. I even had a billet roller cam submerged Arc welded to fill the groove on the front journal of the cam for my 87.

 

[A2000RICH]

Pre 86 block were not grooved, so that groove in the cam was needed. The cam groove allows oil to reach the passage on the other side on older blocks. If your 86 block is groove between the oil passages (Under cam bearing), which it should be you are good to go. I even had a billet roller cam submerged Arc welded to fill the groove on the front journal of the cam for my 87.

i knew there had to be a good reason but all i ever work on is 109's

 

[ryan319]

it's all clear now. new cam bearings, and hopefully the cam, going in tonight.

thanks!

 

[ryan319]

any tips for replacing the front cam bearing?

 

[1chance]

Well i pop the old one out with a screw driver, then took the new one, put some grease on it,a block of wood 2x4 a rubber mallet and tapped it in. I ran into that same problem with my 4.1, got a new bearing from T/A performance, it has a groove cut on the outside of it.

 

[A2000RICH]

any tips for replacing the front cam bearing?

obviously you have to pay attention to where the oil holes are and line them up so they are like the old ones--------i have a tool (for some strange reason they call in a cam bearing installation tool) that makes it easy----- it fits inside the bearing with a small lip to push the bearing in---------it makes it easy but since all you are doing is the front one the block of wood just might work------sometimes stores like AZ or Advance loan tools and i think i have seen cam bearing tools on the list--------good luck...........RC

 

[Lee Thompson]

bearing

Not trying to be picky, but the front bearing can go in in any position as long as there is a groove in the block. IMHO, one of the oil feed holes should be @ around 5 o'clock. This psoition puts oil on the journal just before it reaches bottom as this is where the greatest pressure is. I take the other 3 bearing and cut a groove on the back side large enough to feed a .080 hole. Install with the factory 1/4 feed hole @ 12 O-Clock--drill a .080 hole @ 4-5 O-Clock with the groove running from the factory oil slot (8-9 o-clock) to the 5 o-clock position. Clear as mud?

 

[bison]

Not trying to be picky, but the front bearing can go in in any position as long as there is a groove in the block. IMHO, one of the oil feed holes should be @ around 5 o'clock. This psoition puts oil on the journal just before it reaches bottom as this is where the greatest pressure is. I take the other 3 bearing and cut a groove on the back side large enough to feed a .080 hole. Install with the factory 1/4 feed hole @ 12 O-Clock--drill a .080 hole @ 4-5 O-Clock with the groove running from the factory oil slot (8-9 o-clock) to the 5 o-clock position. Clear as mud?

Thats what i do

 

[ryan319]

i called around to all the local parts stores and nobody has a cam bearing tool. i think that i'll go at it tonight with a block of wood and a hammer.

 

[Lee Thompson]

cam bearing tool

I have one that I would loan but since you don't give your location and I'm not going to ship it---

 

[ryan319]

i got the old bearing out and the new one in.

how far in does the new bearing have to go? both holes are lined up with the oil passage in the block and the bearing is inside the front of the block. i ran a straight edge over it to be sure. it doesn't look like it's in as far as the old one but i'm afraid to push it in another 1/32" and risk damaging it. any way to measure or check if it's in far enough? or am i ok since i'm lined up on the oil passages in inside the block?

thanks again for all the advice.

 

[ryan319]

just a tip for anyone installing the front cam bearing with the motor in the car. i purchased a wooden chair leg from lowes for $8. it has the perfect rounded shape on the end to drive in the bearing without damaging it.

i used a piece of 2x4 to drive the new bearing most of the way in, and finished it off with the chair leg.

 

[A2000RICH]

i got the old bearing out and the new one in.

how far in does the new bearing have to go? both holes are lined up with the oil passage in the block and the bearing is inside the front of the block. i ran a straight edge over it to be sure. it doesn't look like it's in as far as the old one but i'm afraid to push it in another 1/32" and risk damaging it. any way to measure or check if it's in far enough? or am i ok since i'm lined up on the oil passages in inside the block?

thanks again for all the advice.

the thrust surface for the cam is the machined front surface of the block so as long as the bearing is flush or just below that surface it should be fine

 

[ryan319]

yep, that's where it's at. the cam button is set and the valvetrain is all in and setup.