Hello everyone. Wondering if anyone has any experience with issues with Cam shaft bearings. About 2-3 weeks ago i pulled the old cam shaft. It wasn't too difficult to pull out. At least not so difficult I can remember having any issues. When I went to install the new comp cams camshaft on sunday I couldn't get it to go into the final rear bearing. No issues sliding it through the first 3. So i was like ok maybe i got the wrong size cam or something or there is a machining error. Nope. Measured as close as possible between the two and they appear to be the exact same size. Part number is correct for the replacement. So my next step was lets try fitting the old one back into the engine to see if maybe i just got a dud from comp cams or something. No luck. Same exact issue. It will NOT seat in the last bearing. It's as if the opening is just a hair too small. Anyone got a fix for this that doesn't involve me pulling the engine entirely and having the bearings replaced? Is there a way to press in a new rear bearing from the back of the engine without pulling it? The engine was running before I started my big teardown project a bit over a year ago so I don't know why neither the old or new cam will fit.

 

You can make a crude bearing hone out of the old cam's journals. Cut a thin groove (and deburr carefully) at an angle to axis, to remove some material as you turn it.

For me it was bent cams. All cams have some runout, check yours with a simple v block of some type. Binds on last bearing....

 

Are you using a cam handle when trying to install it?

 

Given cam clearances are around a few thousands, a runout error on any of the inner 3 journals of half the clearance will start to bind. Once at clearance amount, adjacent journals have no room for an oil film and will fail.
I had a new cam come in at 0.010, horrific, it was 'straightened' by manufacture to about 0.005, still bound completely up. Next replacement was about 0.0015. Some drag but went for it. Stock cam was very good at <0.001, smooth as butter with new cam bearings.

So I ended up with some extras used as fridge handles. can see the ream groove on the left one.

 

I made my own version out of a piece of steel i had lying around. Just something to give me a little leverage just for when it gets to the rear bearing and i have nothing to grip. But obviosly I'm still going slow and steady when trying to install.

 

I will attempt this.

 

I'm late to the party here.
If the old cam slid out easily but won't go back in, that tells me there is no problem with either cam in theory. The problem has got to be something in assembly. I don't mean to sound like I'm pointing a crooked finger, just reality. Are you using something screwed into the front of the cam long enough to give you leverage while poking the cam in there? Did you put install oil on the cam lobes and bearing surfaces before poking it in there? Did you put a film of the same oil on the block's cam bearing surfaces?