New cam and bearings hard to turn

Samplingman

Old Man with a Hat
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So today I decided to start putting the engine back together. The machine shop installed new cam bearings and I got a Melling SPD-11 CS-327. It was the closest I could get to stock. I lubed everything with the cam lub. The install went well until the last inch. I used the bolt to turn the cam to get it the rest of the way in, but now is is tight. I can turn it with a wrench but not with my hand. Is this common with all new bearings and cam, or do I have to lug the whole thing back to the engine shop?
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That is absolutely not correct. That cam should turn very freely by hand. This a fairly common problem with RB motors for some reason, from what I've learned over time. I've never had that problem with bearings that I've installed, so I don't know why. But.....that cam has to come out and the tight spot(s) either burnished with a bearing knife (a professional's task) or new bearings.

I just saw a vid or an illustrated article about this very subject recently. Maybe I can find it, but you probably can too, now that you know you have a serious problem. "440 cam bearing failure"
 
That is what I was afraid of. We pulled it out just a bit past the last bearing and it spun freely. I took a straight edge to the cam and it does not appear to be bent. Pistons and cam are all installed, wonder how easy it would be for them to replace the cam bearings? And to think I was going to have them finish the assembly, but thought my son and I would have some fun putting it together.
 
Replacing cam bearings is easy for any engine shop. It's a 30 minute job once the engine is on the stand, etc. Make sure you give them the cam, too, so when you do get it back to your garage you know it's ready to assemble.

When you pull that cam back out (if you can) you'll probably be able to see which bearing (or bearings) are causing the problem....scuffed surface.
 
Just tried the old cam with the same result. Anyone use the trick of cutting a diagonal notch in the last journal of the old cam to clean up the bearing?
 
Replacing cam bearings is easy for any engine shop. It's a 30 minute job once the engine is on the stand, etc. Make sure you give them the cam, too, so when you do get it back to your garage you know it's ready to assemble.

When you pull that cam back out (if you can) you'll probably be able to see which bearing (or bearings) are causing the problem....scuffed surface.
Probably the best bet. Also can’t get the double roller chain to fit either, looks like I need a 1/16 of an inch of chain slack for it to slip on. I’m much more comfortable welding and finishing body panels than wrenching around motors, that’s for sure.
 
I was at my machine shop guy's place one afternoon. He'd done a short block for a Chevy 454 customer. When the customer went to install the cam, it went just fine until that last cam bearing. Prior to that, it acted as it should, being easy to turn.

With the engine on the customer's pickup tail gate, Tom removed the rear block plug to expose the rear cam bearing. He took out his pocket knife and shaved the bearing material, all around the bearing, until the cam fit and turned easily. Then put a new plug in the block and it was done. Obviously, it was not the first time for a tight rear cam bearing! So, not just a Chrysler B/RB issue, by observation!

No need to replace all of the cam bearings, just knock out the rear one from the backside, IF there's a plug back there (which I suspect there would be for the initial factory machining.

It's not a "hard fix", but harder the farther along you are in the engine installation process. Nobody's fault that these things happen, either. Just one of those things to check before the engine is installed.

Probably not the first time it's happened at that machine shop, either.

Take care,
CBODY67
 
Common issue nowadays.
When I had my 318 rebuilt for my Waygun same thing.. Tight on one cam bearing.
My buddy specifically asked the machine shop not to knock out the old cam bearings they were fine.
Well the machine shop ignored that and jammed in a new set after hot tanking the block.
We had to burnish the cam bearing until satisfied.

Glad you are addressing it now rather than later.
Using the old cam for the fitting is key. You dont want to damage your new cam
 
I scrapped one once that was tight. It worked out OK, but since the engine is assembled, I'd say that scrapping might not be real easy.

That said, if want to pull the plug out of the rear and you can get at the last cam bearing (assuming that's the one) cover it with magic marker and stick the cam back in. You might just have a small high spot or even just nicked it just enough putting the cam in to cause you some problems. I'd probably do that.

And what the hell is going on with that "Here lies my sister" in the background?
 
I scrapped one once that was tight. It worked out OK, but since the engine is assembled, I'd say that scrapping might not be real easy.

That said, if want to pull the plug out of the rear and you can get at the last cam bearing (assuming that's the one) cover it with magic marker and stick the cam back in. You might just have a small high spot or even just nicked it just enough putting the cam in to cause you some problems. I'd probably do that.

And what the hell is going on with that "Here lies my sister" in the background?
LOL, that’s a Halloween decoration my son made in scouts years ago. The other side says something like “here lies Nicky Noodle, he was attacked by a pack of poodles”.

There is a new plug back there, easy enough to knock out and scrape the bearing, I think I will try that. I have a call into the machine shop, I’ll see what they say on Monday. They are old school and easy to deal with, he might just suggest that. I am worried about the timing chain not fitting, I can’t imagine stretching a double roller. The other chain had about a 1/4 inch of play and slipped right on, gears are steal and look like a recent replacement, I might just clean them up and go with that.
 
Soak the timing chain in light motor oil overnight, double roller needs to be properly lubed to fit correctly.

Dave
 
Careful, careful......no cam ever gets tight until it's all the way in. Meaning it's not always the No 5 bearing. Only a 20% chance it's that one. See this chart from your FSM?

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The bearing journals get smaller as they go from 1 to 5. Number 5 always goes thru the other 4 bearings, 3 always goes thru 1 and 2, etc. But when all five have to fit in their respective bearings, that's when you have this problem. Point is, it can be ANY of the five, not just number 5.

Oh, another thing. When I've knocked cam bearings in (30 years ago), I've always run a long drill--same diameter of the oil feed passage--down that passage at bearing 4 to gently drill out the bearing if it hasn't been clocked properly during installation and is thus blocking the feed passage.
 
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Just tried the old cam with the same result. Anyone use the trick of cutting a diagonal notch in the last journal of the old cam to clean up the bearing?

Unless you can identify which bearing is tight, you have to make that diagonal cut on all journals. I have never done this trick myself. But since you have the old cam, why not try it?

You WILL be removing the crank/pistons before you do this, and then cleaning the block of your shavings, right? :eek:
 
Just tried the old cam with the same result. Anyone use the trick of cutting a diagonal notch in the last journal of the old cam to clean up the bearing?
Did that on my last motor, worked perfect. Used a dremel cutting wheel. No issues at all. Just have to make certain you get no shavings in motor, worst case disassemble & wash.
 
The old school method is to put a light coating of Prussian Blue on the camshaft journals and turn the cam a couple of turns. The high spots on the bearings will pick up more of the blue and they will be marked for you so you remove bearing material from the right spot.

Dave
 
Thanks again everyone for all the help. We popped the rear cap and could see right away where the high spot was just from rotating the cam a few times with the breaker bar. I didn’t need to cut the old cam, I used 600 grit soaked in oil to hone the bearing. We were able to see high spots on the other bearings and repeated the process until I was able to spin the cam with two fingers. As a precaution I used a magnet to pick up any stray flakes and repeatedly squirted light motor oil to flush any debris. @moper was right, the chain fit when everything was in the right place, although there is absolutely no slack. I was able to turn the whole rotating assembly, no binding or scraping sounds.
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Oh, another thing. When I've knocked cam bearings in (30 years ago), I've always run a long drill--same diameter of the oil feed passage--down that passage at bearing 4 to gently drill out the bearing if it hasn't been clocked properly during installation and is thus blocking the feed passage.

I did notice some misalignment on #5:

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