440 block, new cam and new bearings. Oiled the bearigs and used the cam lube on the cam.
It should spin by hand, right? This does turn but takes about 30ft/lbs.

So, back to the machine shop or can I use a little emery paper?
Thanks,
Roy

back to the machine shop. Incist that they REPLACE the tight one.

a brake hone w fine stones for cam journals 1,2,4,5 & fab an extension for your hone to reach #3

This isn't uncommon. I'd recommend you take the block and cam to the shop that installed the bearings and get them to fix it. Honing the bearings ID larger isn't the way to fix it,if you want to fix it you'll need to scrape the tight spots very carefully. Unless you know what your doing just take it back and have them fix it.

Is this caused by having one (or more) of the bearings slightly out of alignment when it was installed? So in effect, it's squeezing the cam?

If so, could it be fixed by replacing the (errant) bearings again, and hoping they go in correctly?

(Curious, so I'll know what to do if I ever see it in the future)

-Dave

Could be the bearing bores are not aligned,the bore(s) are not correct diameter,bearing out of spec,etc. You could replace a single bearing,may not fix the problem. You can install the cam,rotate the cam,remove the cam and inspect the bearings. You will see the problem area. If you don't feel confortable removing the tight spot(s) just have your shop do it.

Thanks for the posts.

It should go back to the machine shop but he's REAL slow to get on anything that isn't used for weekly racing. I'll call him later today and persuade him

Do not use a hone or paper, or any abrasive on the bearings... As wa said, the technique is to use a sharp blade to scrape away the high spots that make the cam hard to turn. That's it. Not hog the hole out until it fits. By installing the cam with light oil (I use WD40) and turning it you will see the tight spots as shiney areas. Then I use a single edge razor blade (KD Tools I think used to make a fancy cam bearing scraper tool) to scrape the high sprots and remove a very thin layer just from that spot(s). When I can tunr the cam by hand with two fingers (little effort) it's done.

Before you do anything with the cam bearings, put the cam in some V blocks and check it for straightness. Shouldn't be out more tham .003". If your machine shop is on the ball they would have a mock-up cam that they ran through the bearings to make sure you didn't have this problem.

core shift, cocked bearings, bent cam ... all BS !!

This is one of the most common big block problems and for the REAL lowdown read this:

http://www.musclemotorsracing.com/muscle-mike-blog

Short of $1000 fix, I'd be going in to the tight bearing(s) with a hone and hoping to hell they don't need much taken off.

I had the same problem with a 440 block. I had one tight bearing. I worked on the tight spot for over an hour until I got it loose enough to spin freely.
I just wasn't comfortable about the job, so I got another set of bearings and replaced the original tight one, problem solved. The cam spun freely without any further work. I figure the bearing may have been slightly cocked during installation or was undersize.

This will blow your mind but it is FACT.

The factory always did a halfass job boring the cam tunnel. They didn't really care...because the OEM cam bearings were WAY undersized, they then line-bored (precision) the BEARINGS.

Now you know why all the old MP manuals suggest not changing the cam bearings unless absolutely necessary!

About all you can do is use a bearing knife or an old cam with sharp grooves to act as a reamer.

Rick

I have a 72 440 block that is a total mess as far as the cam bearings go.

When I first got the car the block was in (1988) I tried to swap cams. 2 of the cam bearings were spun. Finally got 2 bearings back in the dang thing...after a few stitches due to cutting a finger on the bearings.

I had to pound the cam into the last set of bearings. It was so tight the motor would barely turn over. Once it did light, it clearanced itself pretty quickly.

When I tore that motor down and re did it, had new bearings put in. Same thing as before, cam was way tight. We screwed a grade 8 bolt in the end of the cam, chucked the bolt in a drill and tried to loosen it up. Bad idea, broke the bolt off in the cam.

Had to take a stock cam and groove it to ream the bearings. No problems after that, oil pressure was rock solid. After 1k miles and a couple dozen passes, pulled the motor down, everything looked fine.

Last time around with this block, took it to a machine shop and asked if they correct the journals. I was told no problem, he could use the line hone to fix the journals. Well, he didnt. He scraped the bearings to fit my cam. No biggie, but I paid to have the journals honed, not the bearings.

Did you make 100% sure one of the bearings doesn't have a nick in it? Even the smallest blemish can make it hard to turn.

My brother and I put new cam bearings in every engine we have tinkered with and it's pretty simple to do.

The one and only time I had a problem was when I let the machine shop install the bearings for me. He nicked one + didn't clean the block good enough for my tastes so I bought new bearings and isntalled them myself after re-cleaning the block properly.

These days I just ask for the bare block back and do all the freeze plugs, oil galley plugs, + bearings myself.

The shop did have my cam in the block. He asked me to tighten the main caps and try it. If it still doesn't turn easily, he'll be happy to get it set up again this weekend. He's had the same thing happen on a lot of Mopars.

Thanks again for the response.
Roy