[Fot] Cam Bearings expansion

[gregmogdoc at surfnetusa.com]

Confirm whether the cam is bent or not. Cams can be striaghtened  a good cam grinder should be alble to straighten it. Then if it is still tight, polish or griind the cam journals until you have the correct clearance on each journal. You want to keep the oil clearance withing specs so you don't loose oil flow volume by excess oil bleeding out the sides of the bearings causing a pressure & volume drop at the mains and rods. 


Greg Solow
The Engine Room
Sports Car Specialists
Santa Cruz, CA 95060
831 429-1800



------- Original Message -------
>From    : Scott Janzen via Fot[mailto:fot at autox.team.net]
Sent    : 1/5/2015 6:40:57 PM
To      : fot at autox.team.net
Cc      : 
Subject : RE: [Fot] Cam Bearings expansion

 I've got a bit of cam bind in a new cam I'm installing in the GT6.  It appears to be a combination of slight run-out (i.e., the cam is slightly bent, 1/1000 of runout in the middle), journal size right at the factory maximum spec, and installed bearing I.D. that is at or below the factory minimum I.D.
It's also possible that the block is not bored perfectly straight as the binding is not consistent around the rotation, but another cam I have, with journal diameters 5/10,000 smaller, turns freely.  I have not checked that cam for run-out.

Question is, is there a tool to "expand" the bearings into the block and possibly gain a bit of clearance?  I'm told the factory manual for one of those Octagon cars calls for such a tool.  I'm using the typical Spitfire bearings.
Next stop is a machine shop with a crank straightening machine to see if they can use it to straighten a cam.





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