The Basic Kit
The untimely death of Randy Durrance on June 7, 2003 at the age of 45 left a void (among other things) regarding the application of the PerTronix solid-state Hall Effect ignition kits on vintage Mercedes-Benz vehicles. Occasionally, I get inquires about which specific PerTronix Hall Effect ignition kit is right for their Mercedes-Benz. When in doubt, try contacting PerTronix directly. You can find them on the web. Be prepared to give them your Bosch distributor number, which can be found either in your shop manual, or on the metal tag located on the side of the distributor itself. - Jeff Miller / October 2, 2003.
Update / January 7, 2006: |
After several years of making custom ignition systems for Mercedes-Benz Type W109 300SEL 6.3 sedans and 300SL roadsters, I was rebuilding ignition distributors for other models as well. Many of my customers were looking for a system to eliminate their ignition contact points without going the full-ticket ($$$) for a custom made ignition. Since I have had bad experiences in the past with optic-trigger systems (I once worked on Jaguars), I was not interested in using any of the "universal" systems made by Crane® (Allison) or Mallory®. Some of their kits required adaptations that were irreversible. I tried a kit made by PerTronix and was very pleased with the results. Though the coverage is limited, the pieces fit without changing the distributor internals or housing. Over the last few years I have learned which pieces to mix and match for applications that PerTronix does not list.
The picture above is all there is. The kit consists of a Hall Effect switch mounted on a bracket and a fitted ring with embedded magnets to trigger it...no external box, no "erector set" brackets, no plastic wheels...just the pieces needed to make it work.
I had been sent a distributor from an early 1960s Mercedes-Benz Type W111 220Sb "Heckflosse" sedan (Bosch distributor V JUR 6 BR 47 T) to rebuild. The customer also wanted to convert from points to an electronic trigger system. The picture above is the rebuilt distributor ready for the PerTronix kit.
To make clearance for the magnetic collar that will fit over the breaker cam, it was necessary to modify the bracket for the vacuum advance arm. The bracket on the left is the modified version. Easy enough after a few minutes with a die-grinder.
First, the base plate for the Hall Effect trigger is mounted where the ignition points were.
Next, the Hall Effect unit is mounted to the studs on the base plate and the wires are fed through the hole in the housing where the points terminal was.
This part can be a bit tricky. The "flats" inside the ring are hard to see. I usually mark the outside of the ring so I am sure that I have everything aligned properly. It is a tight fit and requires a light tap with a deep-well socket over the distributor shaft to get everything seated.
The last thing that gets done is to seal the hole where the wires pass through the distributor housing. There is usually a rubber plug provided. If not, I use grommets. Make sure there is a bit of slack in the wires to allow for movement of the breaker plate when the vacuum unit operates. Then, I like to use an RTV sealant and clamp the wires in place until it sets.[2]
The wiring for these is very simple. The red wire goes to the positive side of the ignition coil. The black wire goes to the negative side of the ignition coil. The system does require a minimum of 1.5 ohms (3.0 ohms for four cylinder cars) across the two small terminals of the ignition coil. The Bosch "red coil" is perfect for the six cylinder cars and does not need an external resistor. The four cylinder cars just keep the 1.8 ohm resistor that is normally used with the Bosch red coil. It does make for a clean installation since there is no control box needed.
Happy Motoring,
Randy Durrance
Vaughn Smith / January 18, 2006
The PerTronix unit is now installed in my 1959 Mercedes-Benz Type W180 220S Ponton sedan. It fired up instantly after installation. I had a spare distributor that I fitted with the PerTronix kit number 1864A. As mentioned earlier, this part is not specifically supported by the PerTronix company for use with the 220S distributor, (Bosch VJUR 6 BR 38). The unit does fit and works, however. The final installation looks the same as the photos taken by Randy Durrance on this page.
Here are some further notes about the installation process.
Vacuum advance hold down arm modification:
The stock piece will interfere with the PerTronix ring. You must remove material from the arm so that the ring does not bind. You should ensure that there is little or no lateral movement in the distributor shaft towards the arm. It is a close fit afterwards. I had to return the part to the grinder to take off more material. You should be able to rotate the distributor shaft and not see or hear any interference.PerTronix ring installation:
The installed height of the ring is at or below the top of the PerTronix module. It seemed to go on easily, but it was not down far enough. It really needed to snap into place with a little force. Make sure that the painted dot on the top of the ring is lined up with the center of one of the flat spots on the distributor shaft. If it will not go on easily, do not apply too much force. Randy mentions seating it with a deep socket and a hammer. I got it on with simple finger pressure.PerTronix module installation:
It is really hard to get this piece in place. The wires run close to the dist side and one nut so there is little clearance. No socket or wrench that I had would fit between the module and the wires. I used needle nosed pliers to tighten the nut. You need to leave a little slack in the wires to allow for the breaker plate to be moved by the vacuum advance.Locktite:
If you do not have any, get some. When the PerTronix parts are installed, it will be a long time before you need to open your distributor cap. Use a drop of Locktite on the PerTronix module fasteners. You can use red or blue. The blue is easier to remove in the future while the red may require the use of a torch.Vaughn Smith / javr@shaw.ca / British Columbia, Canada / January 18, 2006
[1] PerTronix module part number 1864A reference courtesy Vaughn Smith / javr@shaw.ca / 1959 Type W180 220S Ponton sedan / British Columbia, Canada / January 7, 2006.
[2] Be sure to check the finished distributor with the cap and rotor installed to make certain that it turns. In some applications and various rotor designs, it may be required to sand a small amount of material from the rotor's base to get it to seat properly.