The Mercedes-Benz 190SL W121 used seven different types of distributor. None of them is available anymore. A distributor with the part number 002 158 02 01 is available under the Bosch product number 0 231 170 138. However, this is fitted with a vacuum box and has to be converted, as it doesn’t have the same range of adjustment as the original distributors. The difference is around four degrees. Using a stroboscopic lamp, the ignition point is adjusted to 38° at 3500 rpm and must not change to more than 41° at maximum speed. If you set the replacement distributor to 41° at maximum speed, you will get 18° before OT at 800 rpm. This is too much. Maximum ignition timing at 800 rpm is 15° before TDC. This means you have to retard the ignition timing. To make matters worse, the points on the contact breaker that adjusts the ignition timing are subject to constant wear. Retrofitting a transistor ignition system can help with this As we only have one centrifugal adjustment on this distributor, it is not advisable to experiment with different ignition systems on old distributors that already have weak mechanical advance springs and worn shafts. The result will simply be unsatisfactory.
The answer is to fit a contactless ignition distributor with no points and a fixed dwell angle. The adjustment range is exactly the same as the original distributor. Installation is easy. Remove the old distributor, replace it with the new one, attach two cables to the ignition coil, set the ignition timing with the stroboscopic lamp – done. The distributor cap and rotor arm are original parts. If you fit a high-performance ignition coil at the same time, your car will have a much fatter ignition spark, will start better and will have a little more power.
A detailed installation manual is supplied with every order. You can, of course, bring your car to us and we’ll take care of the installation.
We stock these contactless ignition distributors for both four- and six-cylinder engines. They are suitable for upgrading the 190 SL, Ponton, Pagodas, Adenauer and many W111s. Order via our shop: contactless ignition distributor four-cylinder and six-cylinder