Ron,
It's not the lack of lube which ruins the vacuum plates it's the soft metal
they're made from. The balls, about 1/4 the size of BBs or less, dig grooves
in the metal and cause the plates to become notchy. I had a dist with about
40K miles and the plate was bad and it wasn't dirty or lacking lube.
Mike
----- Original Message -----
From: "Ronnie Day" <ronday@home.com>
To: "Roadster List" <datsun-roadsters@autox.team.net>
Sent: Thursday, July 19, 2001 11:04 PM
Subject: Re: Dwell vs Gap
> >jon_wissler@pngc.com:
>
> > Does "Crane" have a website where I could see them tout their
> > product? Why do you say that a re-curved points distributor is better
> > than the Crane 3000 unit?
>
> Don't confuse the method used to generate the spark with the mechanism
used
> to control when that spark occurs. On older cars like ours you can use
point
> type, magnetic pickup, optical triggers and maybe some other methods to
> control the generation of a spark pulse, but then you also have at least
one
> (mechanical advance) and often a second mechanism (vacuum advance) to
alter
> the timing of that spark pulse above idle speed.
>
> Any ignition system based on the OEM distributor is going to have a
mounting
> plate on which will be mounted points or a magnetic or optical pickup. As
> the distributor spins faster the weight and spring assembly below that
plate
> move the plate advancing the timing. If the distributor is equipped with
> vacuum advance, that also rotates the plate.
>
> There are only a handful of BB sized ball bearings in this assembly.
They're
> open, tend to collect dirt and aren't cleaned and relubed like they should
> be, so they tend to wear out. This is why just installing a trick ignition
> setup may not always yield the expected results. You need to make sure
that
> the distributor shaft and body, along with the mounting plate aren't worn
> out.
>
> I'm pretty sure the OEM (set up for vacuum) plate is still available over
> the counter for around $35 list, and I think the non vacuum version is
> available, too. Since the differences between a distributor for an L-6 and
> an L-4 are just the cap and the cam that controls the points, I'll bet
that
> most any "point plate" assembly for a Hitachi distributor can be made to
> work.
>
> I'll dig around here at Courtesy and Trophy and post what I find. I have
two
> or three distributors I need to go through anyway.
>
> FWIW,
> Ron
>
> Ronnie Day
> ronday@home.com
> Dallas/Ft. Worth
> '71 510 2-dr (Prepared Class Autocrosser)
> '73 510 2-dr (Street Toy)
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