No reason not to. A decent machinist with the right gear can do about
anything to a cam. They are castings with a surface hardening treatment.
As long as the cam grinder uses some reasonable treatment there shouldn't
be a problem. I've had just about everything you can think of done to a
cam. The big problems are almost always in the bearings or in the
structure that supports the cam. For pushrod motors that's usually not an
issue. I had journal diameter reduced on a Maserati straight six (a 1967
Mistral) so I could put bearings into the floppy aluminum head without
reducing the beam strength which was already way too low (the stock setup
runs in the aluminum). I've had cam lobes ground completely off, built up
with weld and relocated so I could build a four stroke Twingle from a 350
Honda motor (both cylinders firing at the same time--don't ask why, I was
young and stupid). Reducing the journal size is nuttin'.
-----Original Message-----
From: Brad Kahler [mailto:brad.kahler@141.com]
Sent: Thursday, September 11, 2003 5:20 AM
To: fot@autox.team.net
Subject: grinding cam journals
Amici,
While looking through our pile of good cam cores for Susan's spitfire we
have found we have a lot of the large journal cams that were used in the
mk1/2 and 1500 spitfires.
I know it is technically feasible to turn the journals down. We have a
Paeco cam in the box that was originally a mk1 cam that has had the
journals turned to match the small journal cam. However since its a Paeco
cam we aren't going to use it.
Susan talked with Iskey yesterday and they said they could do it but
apparently they have had very few requests to do so.
Myself, I can't see any technical reason not to turn cam journals down.
However I'd feel more comfortable doing so knowing that others have done
it or would recommend it.
Thanks
Brad
1957 TR3 vintage racer
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