[Fot] Cam Bearings expansion

[MadMarx]

Hi,

 

the machine shop I’m going to straighten the crank with a hammer and a
chisel and bronze layer.

Takes 5 minutes to straighten a crank.

Cast iron parts they straighten with torch and heat.

 

Cheers

Chris

 

 

Von: Fot [mailto:fot-bounces at autox.team.net] Im Auftrag von Diesel
Performance Parts - Info via Fot
Gesendet: Dienstag, 6. Januar 2015 14:11
An: 'Scott Janzen'
Cc: 'fot at autox.team.net'
Betreff: Re: [Fot] Cam Bearings expansion

 

Scott,

 

I doubt if they can straighten the cam they are usually too brittle as
compared to a crankshaft etc.

The old timers used to have a shaving tool for the poured babbit  bearing
engine of days long gone. You could use one of those to “trim” a little off.


 

I would pull the cam bearings double check the cam bores for alignment, and
diameter. If they are OK then make sure the cam bearings are all consistent
in thickness.  If they are then it’s the cam, it is either oversize or
undersize on the nearing journals or bent. 

 

Mark Craig

Diesel Performance Parts, INC.

411 Allied Drive

Nashville, TN 37211

866-455-7788 Phone

615-834-9923 Fax

 

www.dieselperformanceparts.com

From: Fot [mailto:fot-bounces at autox.team.net] On Behalf Of Scott Janzen via
Fot
Sent: Monday, January 05, 2015 8:41 PM
To: 'Friends of Triumph' Triumph
Subject: [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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