cam installation question (bearings?)

[defiance]

Got my cam in today, and went to install it after work ... but no such luck
The cam goes in about 95% of the way, up to the point where the cam is starting to seat in all the proper bearings.  But about 1/5 of the way into the last bearing, it gets too difficult to turn and won't go any further in.
so I did a search here and see that new cam bearings for mopars have to be 'scraped' in order to fit cams?  I've never heard of this. 
The frustrating part is that the closest machine shop I could find with any mopar experience was 80 miles away.  So, when I picked up the engine, it would have been nice if the guy would have mentioned that.

Ok, so now I'm 80 miles from the machine shop and REALLY don't want to have to do that again.  Is there any way I can handle this myself?  For that matter, how do I even identify which bearing (or bearings) is the trouble??

[firefighter3931]

I've used a scotchbrite pad in the past to clearance cam bearings. 

Core shift in the block is the usual culprit with tight cam bearings....just a little massaging will fix it. 



Ron

[chargerbr549]

It seems good a percentage of Big Block Mopars that come through our shop need to be massaged by scraping and or scotchbrite pad like Ron says to get the cam to fit, its best to use a small mirror and flashlight to look and see where the tight spots are.

I am the only Mopar guy in our shop amongst mainly chevy guys so they are always cussing at me when they have to get a cam to fit the Mopars, so I always get to laugh at them and tell them they put them in wrong or something.

Kevin

[firefighter3931]

I am the only Mopar guy in our shop amongst mainly chevy guys so they are always cussing at me when they have to get a cam to fit the Mopars, so I always get to laugh at them and tell them they put them in wrong or something.

Kevin

Now that's funny Kev ! 

Those Chevy guys have no business assembling a Big Wedge....must be the Mopar Gods sending them a message 



Ron

[defiance]

Well, after several rounds of incremental scrubbing (mostly on three as luck would have it), I have it in there.  It's pretty tight to turn still - I can't really grip the gear well enough to do it by hand, but I can turn it with a big ratchet on the cam bolt.  Probably takes about 35lbs torque if I had to guess.
Is this OK, (in other words, will the natural movement of the cam wear off any remaining high spots) or do I need to shave some more still?

A million thanks for the help so far

[firefighter3931]

Well, after several rounds of incremental scrubbing (mostly on three as luck would have it), I have it in there.  It's pretty tight to turn still - I can't really grip the gear well enough to do it by hand, but I can turn it with a big ratchet on the cam bolt.  Probably takes about 35lbs torque if I had to guess.
Is this OK, (in other words, will the natural movement of the cam wear off any remaining high spots) or do I need to shave some more still?

A million thanks for the help so far

In my opinion it needs more clearancing....you should be able to turn it over by hand.

Keep at it with the scotchbrite.....pain in the azz ; been there, done that ! 



Ron

[Rob R]

I've had some trouble with a couple of blocks from time to time...before I start I tq the mains in place before I install the cam brgs ...every little bit helps when it comes to shift...I have some really really old brg scrapers (my Dads stuff) that cut like a surgeons scalpel when it comes to having to trim any brg material...
that cam has to turn FREE by hand...I put the cam gear on them and give them a spin if they don't go 1.5 times around by hand it's back to a little scraping and polishing 

[John_Kunkel]

I've never installed a set of cam bearings that didn't need a little scraping (that's why they make bearing scrapers).

If you have an old cam, make a diagonal hacksaw slit on each bearing journal and use the cam as a reamer; turn it slowly while pushing it into the bearings, the slits will remove material wherever there is a high spot. The high spots will then be visible and can then be scraped.

[defiance]

I don't have an old cam yet - The old motor I just yanked and sold whole.  It was already bored .040 over and needed bore cleanup, so I just cleaned it up and got rid of it ... well, in the process, but still, the point is I can't really take the cam and chop it up
But I found a guy local who said he might have an old stock one in his shop.
So now the cam's in there, but still a bit too tight - I tried a couple more passes with the dremel sanding bit on slow speed, but I guess I'm just being too conservative with it, and since it's not really marking up where it's getting stuck, I'm no longer making progress.

So for now I'm just going to keep moving forward (degreed the cam, all is happy - also measured that the intake valve contacts the piston at TDC with .400" lift...  So no doubt it's an interference motor, but that should still leave a good bit of valve clearance...  I just need to make sure I never break a timing chain

Anyway, went ahead and put the cover on for now, will pull it again when I find an old cam I can convert to a scraper.  Engine is looking a WHOLE lot better with a nice coat of paint, though

http://picasaweb.google.com/defiancecp/UntitledAlbum/photo#5172855466198974242