Knocking in a cam bearing, and it's tight

[sw70rr]

On my current 440 build I encountered a tight cam bearing. The cam would stop just shy of going in all the way. It was obvious it was the rear bearing. I used and old cam with a groove cut in it. I gave it a few turns and refitted the new cam. It when in and turned perfectly. On future builds I'm going to install the bearings one at a time so if the cam gets tight I know which bearing needs to be fixed.

 

[Mike meeks]

I don't try to fight the cam bearing thing, I have the cam journals ground .005 under problem solved. You can go .010 if you need to. Why take all the good material off the bearings? Cam regrinders will do for around $50 give or take.

 

[Cranky]

I made my own cam bearing tool after watching a buddy go down the same road of scrapping the bearings on just about every build just to see if it would make a difference.....and it did. The only cams I had trouble with were the ones that had run out however there were a few that were too snug and if they checked good for straight were polished or ground. Got to where the first thing to do was to check the cam and then install the bearings right after the final cleaning of the block.

 

[69B7RR]

I remember reading somewhere, or being told, that prior to installing a cam and bearings, to re-install & torque down the main bearing caps. This apparently helps true or stabilize the block. A few months ago while doing a refresh on my 383, I discovered the the #2 cam bearing Babbitt top surface was cracked. I dreaded having to replace the cam bearings because of the binding concerns. I tried the above & knocked in the new cam bearings one at a time so if there was a binding I’d know which one. I also put the bearings in the freezer for a while prior to install. Anyway no issues or binding. I’m not an expert at any of this stuff. Whether it was the main cap suggestion or just luck I don’t know.

 

[Krooser]

I am feeling kind of screwed. Dropping the block off at the machine shop and waiting weeks for cam bearings to get installed is one option. Or, find an old cam I should have here somewhere. Cut a slot in the #2 journal and see if I can cut/resize the bearing with it. I am ordering another set of new bearings. I can practice on this bearing, which has been in and out of the hole now. If it works then knock in a new bearing and resize it.

Thanks for that video series Rick. It explains why this happens. I talked with my friend down the street yesterday, he is mostly a GM guy. They dont have this problem.

yes they do...

You can use any stiff bladed knife with a sharp edge.

Before insert besrings were a things babbit bearings were poured into the rods and mains and then scraped to the correct dimensions... if your great Grandad could donit so can you

 

[Paul_G]

I took a good look at my other bearings in this engine. They were installed at the machine shop 5 years ago. They are not like new smooth. I bet they had to make them fit too by guessing which one and scraping them all.

 

[kiwigtx]

Just saw this one.... - - - - - > How risky is removing and reinstalling a cam bearing if oil hole isn’t aligned?