Cam won't fit

[JeffG]

Just got a call from the machine shop. I swapped my recipricating assy over into a new block. They put in the performance Durabond bearings in there (at my request) and the billet roller cam won't fit. Seems the journals on the block are not round and or misaligned. Happen to anyone here running these bearings?

If it was a normal soft babbat bearing it could jsut be scraped. From what I understand, the soft layer on these coated bearings is much thinner. Damn, it worked just fine in my old block Looks like we will have to go with a different bearing?

Thx,

 

[Mark E.]

I ran into a similar problem on a Pontiac 455 years ago. Turned out the cam bearing bores in the block were too tight. Factory used special bearings. The new bearings pressed in too hard and closed up. I had Kaedings hone out the cam bore to the correct size. Who is doing the machine work?

 

[VadersV6]

If the shop has the proper tooling, they can open the cam journals up slightly on the line hone machine.
I wonder what tool they used to install the cam bearings. If one of them is a little cocked, the cam wont go in.

 

[Mark E.]

So what is the scoop Jeff????????

 

[JeffG]

Hey Mark,
Motor is at Gromm's. The latest......the Durabond race bearings were pulled, and Speedpro bearing were installed. Now, the cam magically fits Hmmmmm. I am not going to question it at this point. Just looking forward to actually having a running GN again.

Thx,

 

[Intercooler]

I had the same thing with mine. You mean the performance coated bearings right? They just need touched a little bit and they work fine.

 

[JeffG]

Yep, those are the ones. They said it seemed that the journals were actually out of round, and it was more then just shaving a bit of bearing material.....yet the Speedpro bearings worked right out of the box. Either the Durabonds had some issues, or they were installed wrong (cocked in the journal). Either way, it seems to be okay now.
Thx,

 

[Mark E.]

Good News, That was the easiest answer. Good Luck, Mark