[Supras] N/A cams: snake oil?
Jim Jobe
jjobe2 at supratech.org
Wed Oct 18 10:01:59 CDT 2006
We've set them up on the lathe and in a head using a proper degree wheel and
they're different.
On Wed, Oct 18, 2006 at 06:03:56AM -0700, Jeff Mohler wrote:
> If anyone has a _certified_ set of N/A cams, I have a Cam Doctor that
> I can profile them with that I use for tech inspections at the track.
>
> On 10/18/06, Joel Watkinson <Cars at xantheon.com> wrote:
> > My only question would be:
> >
> > How can you *confirm* (beyond a doubt) that these are indeed NA cams? I
> > mean, if people can part out a Turbo and sell the cams to other Turbo
> > owners for more than they can sell their stock cams when legitimately
> > advertised, some people will just go for the cash regardless of what it
> > may mean morally...
> >
> > I am *not* trying to slam the Supra community. I have gotten *great*
> > deals from it! I've followed the NA vs Turbo cams with interest for a
> > long time. I still have my '87T and a JDM motor that has already been
> > rebuilt and tested and have yet to put it all together along with a set
> > of "NA" cams I also bought from eBay. So, I have a few reasons for my
> > questions:
> >
> > First, for the validity of the information for the community.
> >
> > Second, to see if there is any reason I should install the cams I
> > bought.
> >
> > Thirdly, to see if there is some way I can confirm that what I bought
> > are indeed NA cams (should it be worth installing them per the first two
> > points)
> >
> > Hope this all helps a lot more people than myself...
> >
> >
> > > -----Original Message-----
> > > From: supras-bounces at supras.com
> > > [mailto:supras-bounces at supras.com] On Behalf Of
> > > berniek at technicaldevelop.com
> > > Sent: Wednesday, October 18, 2006 12:46 AM
> > > To: Supras at supras.com
> > > Subject: [Supras] N/A cams: snake oil?
> > >
> > > Hi list:
> > >
> > > Bought a pair of N/A cams on ebay. All of the lobes are
> > > uniformly about .009" to .010" less in height than the turbo
> > > cams. Also, there is only a minimal groove where the front
> > > seal lip wears on the front diameter. So these cams
> > > apparently have not seen much use, and apparently are N/A cams.
> > >
> > > I set up each in the lathe with a flat follower attached
> > > to a 1" travel dial indicator, and a degree wheel at the
> > > tailstock end, held between the front end screw hole and a
> > > live center in the tailstock. A pointer was made out of
> > > wire. I tested both the intake and exhaust cam and could not
> > > find any timing differences between the turbo and N/A cams,
> > > except for maximum lift, a little less with the N/A cams.
> > >
> > > In the data below, the exhaust comparison is shown. The
> > > intake comparison is just about the same. In neither case
> > > did I find a 10 degree difference in duration. I set the
> > > degree wheel to read zero at .050 lift on the closing side.
> > > Because the degree wheel was hard to set precisely the
> > > estimated error is plus or minus .003" to .005" in lift.
> > > However, a 10 degree difference in duration would have shown
> > > up. I can list the intake data as well, but it is just about
> > > the same is exhaust data in each case. Bear in mind that
> > > angles shown are camshaft, not crankshaft degrees.
> > >
> > > Exhaust: open to close, .from top to bottom in table, 050"
> > > lift set to 0 degrees closing.
> > >
> > > Turbo Lift Turbo angle N/A lift N/A angle
> > >
> > > .000 -130 .000 -130
> > > .008 -120 .010 -130
> > > .017 -110 .013 -110
> > > .048 -100 .056 -100
> > > .120 -90 .122 -90
> > > .193 -80 .197 -80
> > > .250 -70 .250 -70
> > > .284 -60 .279 -60
> > > .296 -50 .288 -50
> > > .285 -40 .278 -40
> > > .249 -30 .247 -30
> > > .192 -20 .190 -20
> > > .120 -10 .119 -10
> > > .050 0 .050 0
> > > .016 +10 .015 +10
> > > .009 +20 .012 +20
> > > .001 +30 .003 +30
> > >
> > > Any information from anyone who has researched this subject
> > > would be appreciated.
> > >
> > > Thanks.
> > >
> > > BernieK
> > > _______________________________________________
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> > > Supras at supras.com
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> > >
> > >
> > >
> >
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>
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