To all those who've been following the Pertronics performance investigation:
Distributor "A" (points--all new components) now installed and running. Problem
had been bad spade connector, at dist. for lead from coil (-).
Timing set to 16 btdc; dwell to 53 degrees.
Observations (subjective): Seems to run great; performance seems
indistinguishable
from Pertronics, dist, "B".
Will perform timed "hill climb", at full throttle, on somewhat remote,
little-traveled roadway near top of Hualalai. Will repeat test immediately,
after
installing dist. "B" (correct timing orientation, already determined).
Should be fun and interesting--if not necessarily meaningful ;-).
"David R. Conrad" wrote:
> Fred:
>
> I make no claim as to improved performance with the Pertronics, as I
> said in my
> post on dwell adjustment--I simply don't know if my recently improved
> performance can be attributed, even in part, to it.
>
> I can however, participate in a pseudo-scientific test in an attempt to
>quantify
> any difference.
>
> The reader must (rather carefully) follow the rather complex situation
> I'm about
> to explain in order to avoid confusion ;-).
>
> I have two distributors, essentially identical as to advance curve,
> etc., and I
> will refer to them as "A" and "B". "B" for "bad", maybe ;-).
>
> "B" was my installed dist. for many years until I started to notice that
> if I
> set the point gap on one lobe of the cam, it would vary by a thousandth
> or so
> from the gap set on another lobe of the cam. The dwell meter would also
> "oscillate" slightly about a mean value.
>
> I decided to substitute dist. "A" which did not exhibit these characteristics;
> in fact, with dist. "A" the dwell meter gave a "rock solid" reading.
>
> I had been running with dist. "A" for quite a while (at least several years)
> when I decided to install a Pertronics unit with the hope of improving
> performance. I installed the Pertronics in dist. "A". Turns out, I installed
> it incorrectly (I plead inadequate installation instructions) and I
>experienced
> several occasions of the car starting to miss, backfire and quit in some bad
> situations. Through consultation with "the list" (Jim Tyler, Dan
> Neuman) I
> identified the problem as being the fact that I hadn't secured the
> ground wire
> to the advance plate, as it should have been.
>
> So, having had my confidence in the Pertronics unit somewhat shaken by my
> experiences while it was incorrectly installed, I decided to install it
> in dist.
> "B", and completely refurbish dist. "A" with all new components (points,
>rotor,
> condenser. and cap), properly gapped, so that I could just "slap it in"
> in the
> event of a Pertronics problem (if I was disabled on the "no shoulder,
> two lane
> road" on which I've had my most distressing problems).
>
> Now Jim Tyler did not like the fact that I had installed the Pertronics
> in "B",
> the "lesser" of my two distributors, contending that "shaft slop" would
>degrade
> the Pertronics performance. No such "slop" was apparent to
> me--absolutely no
> discernible movement laterally. I attributed the slight gap variation
> to cam
> wear. (I agree it is difficult to rationalize how a rotating cam would
> experience differing amounts of wear of the lobes).
>
> Anyhow, the dwell meter shows a "rock solid" indication, whatever that implies
> with a Pertronics, and it runs (subjectively) "great". Dist. "A" with
> the all
> new points components did not work when I replaced "B" with it.
>
> With "B" working well, I've developed enough confidence that, back up "A"
> remains in my workbench cabinet, awaiting the time that the Datsun
> allows me the
> time to investigate the "why" of it not working.
>
> Sorry this has gone on so long, much more so than intended. Anyhow, the
> pseudo-scientific comparison motivates me to "slap in" "A" and get it working
> :-).
>
> I welcome any thoughts regarding the conduct of my comparison tests.
> What kinds
> of things would best be compared? Hopefully, there can be a measurable
> difference in performance and/or fuel consumption, but it would be just as
> meaningful to find out there is no statistically significant difference.
> Maybe
> it will be possible to arrive at something better than the subjective
> terms/opinions we use (nothing wrong with "sluggish", Fred ;-) )
>
> --but I doubt it...
>
> Dave
>
> '"cool" '68 1600
> Kailua-Kona
>
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