[T3] Delta Mark 10 CDI Ignitions

Jim Adney jadney at VWType3.org
Sat Jan 7 20:23:29 PST 2017

As many of you know, I have used Delta Mark 10 Capacitive Discharge 
Ignitions in many cars, including all my Type 3s, since 1966. I'm 
completely sold on them. They aren't magic, but they give much longer 
point and plug life and a spark that will start the car under the 
worst possible conditions. No, they don't increase engine power 
output, and the cap, rotor, wires and insulators all have to be in 
good condition for them to work properly. They are designed to work 
best with a standard coil. They actually work worse with fancy coils.

These CDI's are not sensitive to dwell and they will run to well over 
twice our red line. 

Delta was a company in Colorado that first produced the Mark 10 CDI 
in the mid '60s. They sold it in both kit and prebuilt form. Somewhat 
later, they created the Mark 10B and the Mark 10C. The B version has 
a switch and the C version is supposed to have more power, although I 
don't see how that could be useful and I've never seen one.

While the original Mark 10s were available in 6 and 12 V versions, 
pos or neg ground, the B & C versions only came in 12 V neg ground 

The B version is my favorite, because the switch is often useful and 
this version was also sold by Heath as a Heathkit and by Radio Shack, 
under the Archer brand. I believe there was also a Knight version, 
but in all cases the only difference was the sticker on the outside. 
Inside they were all the Delta Mark 10B design.

I built a number of the Delta kits back in the day, and I've had 
several of the Heathkits, including one currently in one of my 
Squares, but until this week, I'd never seen one of the Archer 
versions. I just picked up an almost complete, unbuilt, Archer 
version. I'm willing to sell it for $80, unbuilt (I'll make sure all 
the parts are there) or built and tested for $150. Either way, the 
price includes the original Radio Shack assembly and user manual, as 
well as my own instructions.

I also have several Mark 10s and Mark 10Bs, assembled and tested, 
available for sale.

With this score, I also got an Archer "Dwell Extender." I've never 
seen one of these before, and they have little utility with a CDI, 
since the CDI's are not sensitive to dwell. I'll have to see if the 
Dwell Extender is working before I offer it for sale, but if it is, 
it might be useful for someone who wants to stick with the stock 
Kettering ignition but wants better performance at high rpm, where 
dwell starts to be important.
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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