Cam Bearing Alignment

Flyboy1400

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I got my block back from the machine shop this week and after getting it on the stand and looking it over I noticed a couple of the cam bearing oil holes aren't fully lined up with the oil holes. Specifically the #4 and #5 (worst) are a bit off, this is my first time rebuilding an engine, I'm wondering what those of you with more experience than I think of this. Is it "close enough" for enough oil to get through? I suspect not as I would think the hole size is engineered to allow x amount of oil flow for a reason, and if it needed less, the hole would've been drilled smaller from the factory...then again I may be overthinking this. If the general recommendation is to get the holes lined up I'm left with a couple options.

1) drill or file the bearing hole a bit wider to match the oil hole in the block
2) buy an inexpensive cam bearing tool on amazon/etc and learn how to knock it out and reinstall it myself
3) take it back to the machine shop. While this seems like the best option, It would be at least another month until I could get time off from work during business hours to get it back to the shop.

number 4-1.jpg
number 4-2.jpg
number 5-1.jpg


First 2 pictures are the #4 bearing the hole to the driver side head almost perfectly aligned, the passenger side head hole however is partially blocked.
3rd picture is the #5 bearing it is the worst of them.

What are your thoughts and opinions. Are these holes "close enough", Is drilling/filing the hole a reasonable solution? If I do buy the tool and knock these bearings out, can I reuse the bearing or would I need to buy another set?
 

wagonman

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I would not be happy with it. I guess you could massage it a bit with a Dremel, the shell not the block. Others will chime in.
 

mopar 3 B

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Close enough to do the job. Heads are the last place oil goes to in the Chrysler block. I have definitely seen worse. I would lube the cam and see if it fits before jumping the machine shops case. If the bearings have not been sized, then you have a beef.
 

R413

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It is just fine like it is. forget about it and run it. On bearing number 4 there are three holes. Does any one of then line up correctly?

You can take them out and put them back in again, but they should only go in one time and stay there.

cheap tool from Amazon? You know what will happen right? It won’t work with a ****.

the machine shop will not redo it for free, and they will look like that again.
 

Flyboy1400

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On bearing number 4 there are three holes. Does any one of then line up correctly?

Yes, the lower hole (which is slightly oval shaped) is pretty much lined up, maybe a 1/32" off. The Driver side upper (pictured above) is spot on. The Passenger side upper (pictured above) is off by roughly 1/16". Just want to make sure that's not too much of a restriction feeding the passenger side valvetrain.
 

440Coronet500

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They are good as they are, don't cause yourself issues with a Dremel tool. 440'
 

493 Mike

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I don't remember ever NOT having to shave the cam bearings in a big block Mopar. If you lucked out, then you won't have to buy a 3 cornered bearing knife (cheap though)! When the cam is fitted, look for shiny spots/tight areas and shave those. I used a piece of broom handle as an extension to reach the center bearings. I agree with the other members on alignment.
Mike
 

icetech

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They are fine (although the last pic i might open up a little bit with a dremel, but still not gonna be an issue) , and good job checking them... I had a 400 block done and the guy didn't even know he had to line up the bearings.. when i took it back he tried to say i spun the bearing putting in the cam.
 

zyzzyx

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The holes are not that far off for factory tolerances. You can drill the shells by using the original
holes as a pilot, but like was said before, not worth the aggravation. The oil will be 180 degrees
and will flow nicely! Not one of the holes are closed off.
 

69Bee

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I line up the cam/main holes as best I can, and the hole to the heads are a compromise. Sometimes all hole line up, but most of the time, they end up like yours with one head hole slightly askew; it will be fine. As far as #5 bearing, they should have done better with that one. If you did drill it, at least it is on the end and easy to get to in order the dress the babbitt side, but I would probably leave it. If they didn't test fit the cam after installing the bearings is the bigger problem. I won't install cam bearings without test fitting the cam. I usually always have to scrape the bearings on a Mopar.
 

Mr. Cranky

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If the shop used one of those 'universal' cam tools then your cam has a good chance of being tight. I have a 'custom' cam tool and never had a problem with a tight cam....unless the cam had runout. That's another thing that should be checked. Have had a couple of new cams with .005" runout in the middle.
 

beanhead

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Those aren't any worse than some of the 100K+ mile originals I've torn down.
 

66Satellite47

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I've run cam bearings in my 7000 RPM drag motors that look about the same. The #4 look pretty normal, #5 is a little more off, but likely OK.
 

ykf7b0

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When I installed my cam it would hardly spin due to the a tight fit. I found the high spot on a cam bearing and hit it with some emery cloth till the fit was free. It’s been doing great for 21 years now.
 
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Flyboy1400

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It seems everyone pretty much agrees that it's close enough to do the job, so I think I'll likely leave it be and run it as is. Thanks guys, you've alleviated my concerns with the oiling holes.
As for cam fitment the machinist did mention that he had a cam to test fit the bearings with, so that left me with the impression that he indeed did test fit a cam when installing the bearings. I should have the cam I intend to run sometime middle of next week, when it gets here I'll definitely be checking it for runout as suggested, and test fitting it.
 

66Satellite47

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You definitely need to check the fit of the cam you will actually run.
 

Flyboy1400

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Well I finally got some time this weekend to test fit the new cam and sure enough it's a bit tight. It goes in ok, but wont quite rotate by hand. I put the timing gear on and can easily rotate it with that on, but it does feel tight. After pulling the cam back out I did notice some shiny spots on bearing #2, 4 and 5. So learning to scrape bearings is now the next step for me.

I also did check the runout, new cam has ~0.002, for reference I also measured the old stock cam that came out and it has ~ 0.007 !! I have been unable to find a specified tolerance for cam runout, does anybody here know what an allowable tolerance would be for camshaft runout?
 

Geoff 2

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Did you compare the journal diam of new & old cams? It could be the cam journal that is oversize. I had this happen with an Isky cam. I would take a thousandth of the journal rather than 'scrape' the brg.
 
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