Dan_gearhead

Well, took out the cam yesterday, and this is how the outer bearing looked like:
http://user.tninet.se/~isb540p/sent/yttre_lager1.jpg
http://user.tninet.se/~isb540p/sent/yttre_lager2.jpg




Since I don't have that much experience in how/if you can see on the journals whether the bearings are ok,
well except for the outer one which look like this on the cam:
http://user.tninet.se/~isb540p/sent/kamaxel42.jpg

1.
The other journals I'm not sure about, but if someone can take a look and post your thoughts:
http://user.tninet.se/~isb540p/sent/kamaxel12.jpg
http://user.tninet.se/~isb540p/sent/kamaxel2.jpg
http://user.tninet.se/~isb540p/sent/kamaxel32.jpg
http://user.tninet.se/~isb540p/sent/kamaxel33.jpg

2.
I'm not sure that I've got pictures on all the journals but if any of the other looks like the outer one
can I assume that those bearings are bad as well?

3.
I was also wondering if I can change just the outer one while the engine sits in the bay?

4.
Can you actually determine whether the other bearings are ok by looking at the cam journals and
through the "cam hole"? I was tired last night and a bit dissapointed so I didn't try and look into the engine to check the other bearings before I left...

I appreciate your input!

thnx.

442olds

Well it looks like your going to need all new cam bearings and a cam. You might be able to find a place that can resurface the cam journals, call a machine shop and see what they think.

Its best to change all the bearings when doing it. I don't think you can change just one. I think the bearings have to be punched out from the rear so if you do it in the car your going to have to pull the engine. And they are installed from the front using a tool that is slightly longer than your cam so you'll need a lot of room up front, if you attempt an in car replacement.

Personally I would like to know how that bearing got like that. And if that bearing is that screwed up, I certianly would check the rod and main bearings too. A little metal shaving can ruin a lot of bearings.

1racerdude

Seems like when you change to stiffer valve springs with stock cam brgs things go south.Been there-done that.
The proper way to fix it is to install a set of Clevite HP brgs or your choice top of the line brg and make SURE you have the proper clearance that Clevite recomends .003-.004.
With the extra load of the siiffer springs+the water pump it is to much for the brgs the factory designed to work with what it rolled out the door with and no more.(saving money) Sorry to say I have never seen a set changed without pulling the engine.

But if you are a gambling man----

Dan_gearhead

Well, I was going to put in a new cam so the old cam would not be reused.

How the bearing got to look like this..well I don't know, the car has about 55000 miles on it, and I haven't driven it that hard...and the internals are totally stock as far as I know.

Well I guess it's best to do like you say, pull the engine and open it up to check the main and rod bearings as well...

I feel tired allready

jtk

thats how my cam bearings looked with 35,000 miles. with the year of your car I would think you have at least 80,000 miles on it. So.. it would seem the cam bearings were down to the way you seen them and dont change much after that? there are specs on cam jurnals and lobes, when you get the cam bearings changed out have the cam inspected. you would need to take out the engine to replace the bearings though.

Dan_gearhead

Well it has been totally stock....I was going to change that now with a cam and heads but as it looks now I'm into some more work than just the cam n' heads.....

1racerdude

The cam brgs CAN be changed with the engine out and not taken all the way apart.You will have to talk someone into doing it that way-a real pain-but it can be done.
I would check the rods and mains one at a time and if they look OK,put a new oil pump in it with your new cam and go have fun.

bunker

haha, mine looked way worse, but so do most LT1's, something about the LT1 cam bearings, they get to that stage pretty darn fast I must say, just put your new cam in you'll be fine, mine was 10X worse, i put a light in & the rest seemed acceptable, I mean what can you do, just run the damb thing, I did change the front bearing though, I got a nice thick washer fromt he hardware store, grinded 2 sides off so I can fit it inside the cam bearing hole, got a long bolt 7 nut, got a piece of tube that will go up against the block, & another washer that goes up agianst the tube where the bolt comes through with threaded end, & put a nut on it, basicly 1 washer was inside the bearing hole with bolt, its easy to get it in cuz you have a bolt going through the washer so you can drop it either.

basicly put it in, put the pipe on & 2nd washer on other side of pipe, & start putting the nut on, when the nut is on & a few threads exposed just put vise grinps on the esposed side of the threads so the bolt wont spin, & just keep turning the nut with a wrench, the bearing slides right out smoothly, then put the new bearing in with the oil gallery holes in the 12&3 o'clock position or whatever was stock, sometimes its 1 & 4 o'clock.

Reason why the 1st bearing suffers the most is because of the timing chain pulling down on the cam.

1racerdude

Timing chains have always pulled the same since '55 the extra load of the water pump pushing down on the front brg and marginal brgs are the culprit.

jtk

I beleve cam bearings use babbit matirial over a steel back, witch is very soft. wonder if there are aluminum faced cam bearings.
that water pump gear driven off the cam gear probly dose not help cam bearing life

1racerdude

Dan_gearhead
Pay special attention to the way the cam brg oil holes are clocked.They have a certain way to be installed and your machinest needs to be aware it isn't standard old style.Or so says the chevy manual.

Dan_gearhead

I'll be going with an electrical wp now so I hope that will help the eventually new cam bearing (s) not to crap out this fast..

So basically I'll have to decide if I'll just change the outer one and bolt up or if I should pull the engine and check if the mains and rods are ok to...

Can you pull the engine from top with the heads on? Even the tranny perhaps(m6)?

1racerdude

They make good,passable and best brgs.They all use a very thin coat of babbit.In the '50 the whole brg was babbit and poured in like lead and fitted to the shaft.
The babbit has little to do with the wear factor,it is the type and amount of the other one or two layer's of material that are under the babitt.(depending on the quality of brg) If the backing material is soft and can't take the load you get quick brg wear.

1racerdude

You can support the tranny and leave it in the car,remove the rad,get a HAPPY HOOKER and remove engine.You will have to put the intake back on,and when you go back in it can be all assembled except the exhaust and dampner weight.

Dan_gearhead

Why put the intake back on? Cant you just lift it in a couple of bolts where the intake is mounted to the head, and perhaps using the hole where the wp shaft and bearing used to be?

It looks like this now:
http://user.tninet.se/~xus275f/Bilde...um_en_topp.jpg
But with both heads on and the timing cover off...

The radiator is out but the ac rad is still there, I'll guess that the bracket for ac and ps would have to go as well before...If I opt to pull it that is.