I have a old Cam Doctor I have played with a little. Mine is an original
(remember MS-DOS, card slots). The only advantage to the Cam Doctor is
that it is more accurate than a dial indicator and degree wheel. I would
say that most people will get the information they need by manually
profiling. Rather than measuring at equal numbers of degrees, I find it
better to measure at equal lifts. I have a couple of pages on my website
and an Excel spreadsheet you can download. I have been told the
spreadsheet is a little confusing because with the typical degree wheel
the scales go backwards and forwards (BTDC, ATDC, etc.). You can check
it out at http://tildentechnologies.com/Cams/Tip_DegreeCam.html. I hope
it helps.
?- Larry
On 7/17/2018 12:05 PM, fubog1 via Fot wrote:
> Yes, lacking access to a Cam Doc, you can use a set of V or bearing
> blocks, a degree wheel, dial indicator, and a bit of time, checked at
> 5 cam degrees, works fine.
> I'm still old school though, I plot them out on graph paper!
> That will give you the lobe profile but most folks don't have the full
> specs on the cam, usually just advertised lift and duration.
> Since the tip of the lobe usually starts to go away first, a simple
> lift measurement will reveal the worst, best done with a dial
> indicator cuz some (cheap) cams are ground on different base circles.
> Generally, ramp wear is unusual if the tip is still OK, although there
> can be exceptions.
>
> Glen.
>
>
>
>
> -----Original Message-----
> From: timmmurphh <timmmurphh at gmail.com>
> To: 'fubog1' <fubog1 at aol.com>; rbtr3a <rbtr3a at cox.net>
> Sent: Tue, Jul 17, 2018 12:38 pm
> Subject: RE: [Fot] Cams
>
> By degreeing the cam using increments of 10 crankshaft degrees (5
> camshaft degrees) and then plotting the results in Excel, it is
> possible to get a very accurate picture of the profile of the cam.
> I?ve attached a spreadsheet showing an intake and exhaust lobe
> comparison two years apart of our Kastner G3 cam for reference.
> Tim Murphy
> #317 TR4
> *From:* Fot <fot-bounces at autox.team.net> *On Behalf Of *fubog1 via Fot
> *Sent:* Monday, July 16, 2018 6:31 AM
> *To:* rbtr3a at cox.net; fot at autox.team.net
> *Subject:* Re: [Fot] Cams
> Generally any obvious wear or pitting would make it unserviceable, but
> the wear isn't always so obvious.
> You can measure the lift and compare to spec, that will show any worn
> lobes, but the best way is to find someone who has a "cam doctor".
> It's a machine that sets it up and measures the complete profile.
> Usually if there is anything apparent that suggests that there may be
> problems, there are...
> Glen
> -----Original Message-----
> From: rbtr3a--- via Fot <fot at autox.team.net>
> To: fot <fot at autox.team.net>
> Sent: Sun, Jul 15, 2018 6:47 pm
> Subject: [Fot] Cams
>
> How do I determine if a cam is good or bad. If there are any marks on
> it does that make it bad. I do know that two of the lifters has
> pitting on the surface.
>
> Ronnie
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