Gee Paul, I'd be happy to product test for you to make sure it didn't
spoil while sitting in the box all these years......
69SRL
NOWROC
Troutdale, OR
"Paul" <9laser3@bright.net>
07/20/01 03:54 PM
To: <jon_wissler@pngc.com>
cc:
Subject: Re: Re-Curving the distributor (Long)
I just picked up my non-smog distributor from CDM last fall. There
didn't
seem to be a big rush on them at the time.
Mine is still in the box! I have been making other repairs between
weekends on the road and since the smog dizzy is still functioning (poorly
but functioning) I just haven't taken the time to pop it in. that and I
am
chicken when it comes to tearing a working car apart. I usually wait
until
something breaks to fix it!
Paul
OROC
-----Original Message-----
From: jon_wissler@pngc.com <jon_wissler@pngc.com>
To: datsun-roadsters@autox.team.net <datsun-roadsters@autox.team.net>
Date: Friday, July 20, 2001 6:36 PM
Subject: RE: Re-Curving the distributor (Long)
>Brian,
> Best understandable description I have seen on the subject. I've
>always thought my off the line performance was dismal. It's only when I
>get revved up above 1500 to 2000 rpm's that I have power, and then I get
a
>load of it. I advanced my smogger to about 10 last fall and it ran
better
>in the low end, but getting on it caused it to ping. I just set it back
>to zero and it's running pretty darn good with fresh plugs, points, cap,
>rotor, and condensor. Since I'm an idiot mechanic, how difficult would
>you say it is to "recurve" my current distributor. At one time Les and
>Sport Imports claimed to have new in the box non-smog dizzy for $135 that
>I should have bought right there and then. Any chance there is a NOS
>version of the non-smog dizzy in the Nissan system anywhere? Do our
>vendors have them? That way I don't have to worry about my cam lobe
being
>worn, bad springs, bearings, etc etc etc. My mechanic put a pointless
>distributor in our 69 510 with an L20B and it runs awesome. Could that
>distributor be modified? What the hell is the advantage to points over
no
>points, or is there any. It sure seems like the hassle with points
better
>come with some performance gains.
>
>
>
>
>"Brian Hollands" <bholland@hayes.ds.adp.com>
>Sent by: owner-datsun-roadsters@autox.team.net
>07/20/01 10:08 AM
>Please respond to "Brian Hollands"
>
>
> To: <Robert.Long@CSDInc.com>, "Datsun Roadster Mailing list"
><datsun-roadsters@autox.team.net>
> cc:
> Subject: RE: Re-Curving the distributor (Long)
>
>
>Before the emission controls were put on the roadsters, the distributor
>had
>15 degrees of internal mechanical advance. If you set the ignition
timing
>at 16 degrees BTDC and then rev the engine you will see - with the timing
>light - that the ignition advances or in simpler terms, that the spark
>happens sooner. At full mechanical advance, you would see the timing
>light
>fire at 31 degrees BTDC in the above example. In order to meet emissions
>regs - readings were taken at idle at the time - Nissan retarded the
>timing
>at idle. Emission controlled cars are supposed to be timed at TDC - 0
>degrees. The emission cars still need 30-35 degrees of ignition advance
>in
>order to make power so Nissan changed the distributor so provide 35
>degrees
>of mechanical advance. This way they could time the car at 0 degrees at
>idle but still have the required amount of advance at speed. The problem
>is
>that the cars don't run well with the smog distributor. They don't make
>good power right off idle don't idle well and are very prone to
>overheating
>when timed at 0 degrees. Nissan tried to fix that problem by adding the
>thermal modulator on top of the water neck which is supposed to open up a
>vacuum passage when the engine gets too hot. That vacuum goes to the
>vacuum
>advance unit which advances the timing until the engine cools back down.
>The thermal modulators are often not working or have been disconnected by
>people who thought that it's better to just disconnect that emissions
crap
>not knowing what they are really doing. Many of those folks then time
the
>car at 16 degrees not realizing that they now have 51 degrees of total
>advance which is way too much.
>The solution is to put a new distributor cam and weights into the
>distributor so that it will provide the correct amount of total advance
as
>well as the correct advance curve - the amount of advance at any given
>engine speed. This is called recurving the distributor. It is very easy
>to
>do, you just need the correct parts which, I think are still available
>from
>the vendors. One other option which I am considering is to change
>distributors entirely. The later electronic distributors like those used
>on
>the B-210 can be adapted to the Roadsters and can also be recurved with
>many
>different curves being available.
>You can tell how much advance your dist. has built into it by removing
the
>breaker plate so that you can look inside the dist. You will see a
number
>stamped on the plate at the bottom of the cam. Most common are 7.5 and
>17.5. This number is the degrees of advance the distributor has in
>camshaft
>degrees. Multiply that number by two to see how many crankshaft degrees
>that amounts to. 7.5 x 2 = 15 degrees which is a non-smog distributor.
>You
>can set the timing at idle at 16-20 degrees. 17.5x2=35. You must time a
>car with that distributor at 0 degrees or risk hurting your engine.
>There is more info on dist. swaps at
>http://home.att.net/~jason510/Dizzy_FAQ.htm
>This is L-series info but it applies to the roadsters as well. It just
>might not be cook book simple in an R or U series engine.
>Brian
>
>-----Original Message-----
>
>What does it mean/do, when you say you re-curved the distributer?
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