Camshaft installation issues

[rapid transit cuda]

I have a 383 that I putting together & I have ran into a problem when I was test fitting the cam.
My cam will not fit into the block. it will go almost all the way in but stops when the cam journals are about to slide into the bearings.
I understand that this is not an uncommon problem with the big block Mopar but I did not see any mention of it here on this forum.
I would appreciate any suggestions.

 

[Daves69]

Did you try fitting the old cam? Are these new cam bearings? Did you possibly ding a bearing?

Maybe helpful......

http://www.moparmusclemagazine.com/techarticles/mopp_0810_mopar_cam_journal_sizing/


http://www.forbbodiesonly.com/moparforum/showthread.php?38645-How-To-Install-Camshaft-Bearings

 

[Adam]

Use some dial calipers to measure the I.D. of the bearing and the O.D. of the cam; Also get a good light and look down the bearings for a mismatch or possible damage.

 

[rapid transit cuda]

I do not have the old cam from this block, yes these are new cam bearings.
I do have a cam from another block. should I try it & see if it will fit?
There is a possibility that there could be some damage to one or more of the came bearings.
I have some marking fluid & was planning to use it to see if that would show where the problem is.
I also have a new set of cam bearings if needed.

 

[Adam]

I meant check the O.D. of the cam you were fitting, not the old one. should also be able to check the I.D. of the front cam bearing easily. Im sure you already know but most Dial calipers have inside and outside measuring edges.. If there is damage it is probably from the bearing installation, I cant imagine enough damage occurring from trying to install the cam. Thread a long bolt into the gear end of the cam for a handle.

 

[rapid transit cuda]

Thanks Adam,
I will measure the cam & & bearings this weekend.
I am hoping all that is needed is to chamfer the leading edge of the one or two of the bearings.
I have read that it is not uncommon for the cam journals in the block to have been machined undersized. I hope that is not the case because my options are limited to correct this issue locally.

 

[Daves69]

You may also want to set your cam on V blocks and indicate it to check for any bow.
The front bearing is easy to check fit, just turn the cam around.
I think I'd try the "cam from another block" just to check for consistency. What have ya' got to loose?

 

[moper]

It's very common - and "in the day" (and now when I do it for someone) we would ask for the cam the customer was using. It's common to have to scrape the bearings to fit the cam to them.

 

[rapid transit cuda]

Finally got the cam to fit in the block. It was a tolerance stacking situation that did not go in my favor.
The machined journals in the block were on the small end & the cam had a couple of journals on the big end.
I ended up having to scrape the bearings a little.