Wow!
I got a LOT of good information on this one. I'd like to thank
everyone that responded with suggestions and offers. Fortunately
shortly after posting my note I managed to locate two small journal
1300 cams so I don't have to worry about grinding journals at this
point. I definitely won't hesitate to grind one in the future if need be
however.
It appears that its a common occurrence for FOTers to grind their
own cams. That kinda surprised me. I still have a few of you to
contact directly about your emails to me.
Thanks again everyone!
Brad
1957 TR3 vintage racer
On 11 Sep 2003 at 8:30, kas kastner wrote:
> I don't see any problem at all with turning down the bearing diameter of
> the larger cam cores. If you want, having the camshaft parkerized will
> give a little more protection to the surfaces such as the cam grinders
> usually do, but the bare metal will be just fine also if run in bearings
> not a bare block. I say this 'cause all the cams should be run in
> bearings if they have an upgraded lift curve. You might bear in mind that
> when you increase the diameter you also increase the surface speed and
> also increase the frictional loss (minute) but sitll there. The bearings
> surfaces will work harden a little just as the lobes do. The cast cores
> are ground pretty deep too create the finished lobe and only the work
> hardening is effective in giving the core long life. (my opinion as usual)
> ----- Original Message ----- From: "Bob Bownes" <bownes@seiri.com> To:
> "Brad Kahler" <brad.kahler@141.com> Cc: <fot@autox.team.net> Sent:
> Thursday, September 11, 2003 6:43 AM Subject: Re: grinding cam journals
>
>
> > I'd be more inclined to have the blocks bored out. Larger journal = more
> > bearing surface = less wear.
> >
> > What do you go through more of, blocks or cams?
> >
> > Would also guess the cam journals are hardened along w the rest of the
> > surface of the cam, while the blocks are not...
> >
> > iii
> >
> >
> >
> > Brad Kahler wrote:
> > > 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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