Breakerless ignition is fine for some, but I don't like them. The "classic"
setup gives you more control over dwell. I would recommend the breakerless
ignition for those trying to adjust and fix a sick or wornout engine, as it
eliminates the points as a problem area so one can concentrate elsewhere.
Once everything else is good, one can switch back to points if performance
is your game. As Ron indicated you have to monitor point wear, so
breakerless ignition is better for those who want consistency from their
distributors.
I have found big performance gains from properly adjusted ignition points
versus the breakerless ignition. And this is on three different roadster
engines with three different Pertronix breakerless setups. If anyone has a
way to set dwell on the Pertronix to get a better spark then I'd like to
hear it. Pertronix setups just seem to provide anemic power.
I set my dwell around 53 degrees and the timing around 16 degrees on my SU
2000.
Oh, another thing - I've seen poorly running engines where the driver
attributes the problems to the fuel system, but I see it as bad
distributors. One or more items can go bad in a distributor and adversely
affect performance - worn bushings, wornout breaker plate, worn cam lobes,
worn wires, worn weights or broken springs, bad cap or rotor. (Most of this
is true regardless of using Pertronix or points.) A replacement with a
rebuilt distributor can work wonders (as in smooth running).
Fred - So.SF
______________________________ Reply Separator _________________________________
Subject: Re: Plugs and their gaps
Author: Ronnie Day <ronday@home.com>
Date: 4/6/2001 8:22 AM
>When I had points I had the same problem as the dwell was not in spec when I
>set the points to the correct gap. I read that dwell was more important than
>the gap and you should go for the correct dwell. And I always thought it
>was just me!!!
The dwell is direct effected by the point gap. It's the measurement (in
degrees of rotation) of how long the points are closed. The smaller the
gap, the longer (or greater) the dwell, the larger the gap, the shorter
dwell. Dwell is the more accurate way of adjusting the points because
it's not effected by pitted or nonparallel point contacts. You need to
set the dwell before you set the timing because the timing is determined
by the dwell.
If your points are pitted it's best to replace them, but they can be
filed flat. You should also use a little bit of high temp grease to lube
the rubbing block where it contacts the cam lob. Realize that as the
rubbing block wears the point gap closes and dwell increases. If you
don't use the right lube at this point, the wear will be faster.
IMHO, the best thing to do is to adapt a breakerless (magnetic pickup)
from a later model (late '70s) L-series motor. We've discussed it on the
list before and while I don't remember all the details, I think it
involves combining the top end of the L-4 electronic distributor with the
base from the U-20 if not also on the R-16. Point wear and timing drift
become things of the past. If you want keep the point type distributor
for shows and such, that's great, but I think you'll be amazed at how
much better a car will run with this setup, if everything else is in good
condition. It's not a cure all for a sick or worn out engine.
Maybe TMI, but since you asked.
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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