That's my way too. And if you fit them one at a time you don't have to scrape that much. I do have one of those cheater tools as John pictured but I think it might remove more material than I want to take out.

Can anyone post photo's of what some of those cam bearings look like after they have been "fitted" for the cam? I go over my motor after every season and I bet the looks would scare someone during the first inspection of a winter freshening!

Mike

I always bought into the cam bore alignment problem. did the tricks with an old cam, etc. what got me thinking differently was the last build I did for myself. I put new bearings in and was trying to decide what cam to use (had several on hand). I noticed one cam wouldn't fit and another just slide right in. i'm betting the bearing journals aren't always concentric with the centerline of the camshaft. reason being is the poor fit thing is inconsistent. I don't have a way to measure journal run out but I think it's worth checking if a serious problem arises.

If you have two “V” blocks place the cam on them using #1 and 5 cam journals then check the center bearing for runout.
Compare the cam that fits nicely to the one that does not. Your theory holds water.

Of course you want to make sure the journals are very close in diameter between the cam that fits and the one that does not.

The cam I was using to test fit the cam bearings had one tighter spot on each revolution, it was not the same tightness all the way around on each revolution. I'm going to check it for run out before using it in a motor, it is a steel black coated solid roller cam that I was using for mock up only on this 440 block pump gas stroker motor
I have 5 or 6 solid roller cams in the cam cupboard and this one was the one I grabbed

my thoughts are that the block may not be perfect and the same for the cam. those bearings are babbit and i don't think there ever was a lot of clearance built into the design. after all who in 1956 on the design team would have ever thought we'd be subjecting these engines to the kind of forces a big roller cam can generate. anyhow, a thousandth out here, a thousandth out there and you can get the picture. the only saving grace is the soft bearing will conform;... to a point. I've used the "grooved" camshaft journal idea before but the truth is all it does is conform the bearings to the "grooved" cam and who knows if it's right. I also believe multiple camshaft changes on the same bearings can loosen things up too much.

it would be nice if you have a small dial bore gauge to check the block journal i'd.'s. there may be something goofy there.

The design stack up takes in to account all the vairiables mentioned here - block, cam bearing, journal size variations along with camshaft runout. Blueprints were developed with the min/max sizes and runout.

Testing was then performed using these specs.

Production then built the parts within those specs. At least they tried to.

Mass production, tool life, lack of process control, lazy maintenance play into variations in specs. We have all seen it - blocks differing in deck heights, bore sizes, etc.

Even though developed in the late 50’s, the design is obviously robust enough as we have been using these blocks with conventional bearings with high lift cams and spring pressures probably three times more than designed for.

I have seen it many times - product engineering says “build this” then the plant floor says “we can’t with these specs” then things get loosened up.

Tooling and matching has changed tremendously since then.

Today the engine plant can machine and build an engine that rivals hand built/blueprinted engines from the 60’ and 70’s.
Day after day.