[T3] some problems back, some gone...

Keith Park topnotch at nycap.rr.com
Sun Jun 6 19:48:17 PDT 2021

I don’t know who made the switch,  its one of the little red ones...  its
been in there for years, and I found nothing wrong with the old one,
Ran to the camp Saturday without issue after cleaning up some wiring, maybe
a bad crimp in there but so far so good.

Topnotch Restorations
topnotch at nycap.rr.com
71 Squareback  “Hothe”
65 Notchback  “El Baja Rojo”
93 RX7  “Redstur”
13 Subaru Outback "Blendin"

-----Original Message-----
From: type3-vwtype3.org <type3-vwtype3.org-bounces at lists.vwtype3.org> On
Behalf Of Jim Adney
Sent: Sunday, June 6, 2021 4:04 PM
To: type3 at vwtype3.org
Subject: Re: [T3] some problems back, some gone...

On 6 Jun 2021 at 11:32, Max Welton wrote:

> Also. some interesting thoughts from Fred Winterburn in this thread.
> https://www.mgexp.com/forum/mgb-and-gt-forum.1/interesting-ignition-fa
> ilure-with-heathkit.3510763/

That's an interesting thread, with both good and poor followup posts. I
particularly liked someone's observation that the standard Kettering
ignition stores the spark energy in the magnetic field of the coil while the
CDI stores it in a capacitor.

Here are a few things to consider if you're interested in adding a CDI to
your car. These things would have been useful in that MG thread.

CDIs work best with a standard ratio coil. Performance with a hi voltage
(high ratio) coil will actually be worse than with a standard coil.  

The Delta Mark 10B is a great CDI unit, but its built in switch is its weak
They worked well for a couple decades, but as they got older the contacts
got tarnished and don't always maintain good contact. I have these on all my
old VWs, so I make a habit of exercising the switches any time I'm near
them. They don't fail on me as long as I remember to do this.

Keith's problem may also be in his switch. Keith, any chance that you're
using one of those little Alco 4PDT toggle switches? A full size switch
might do better in this application.  

The original Delta Mark 10 units do not have a switch, so they do not have
this weakness, but they also lack some 10B features that may be useful, like
hotter spark when cranking.  

The Delta literature recommends regapping the spark plugs to .040". This
worked just fine for me until I tried to start my square in damp weather. 
Under those conditions, the extra hot CDI spark found lots of alternate
paths to ground, before it got to the spark plugs. I've stuck with std.
.028" gap plugs ever since. That works just fine.

Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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