The 1963-67 Porsche 912 Ignition distributor
The Bosch 0231.129.022 distributor is used in the Porsche 912 from 1963 to 1967. This is a four-cylinder distributor. It is a cast iron and uses a points and condenser system.
The 0231.129.022 is a clockwise spinning distributor. Weights in the distributor spin out as the revs increase and advance the timing. The weights do the job by sliding on a plate, controlled by springs. Worn out springs can be a problem for the 0231.129.022. This can be why this distributor can hang up and the engine can take a longer time to return to idle.
Rebuilding the 0231.129.022 Distributor
When rebuilding cast iron 0231.129.022 distributor, there are a few mistakes to avoid. The most common problems come from using incorrect parts. A big problem is the use of incorrect springs. The springs in this distributor age from engine heat cycling and do need to be replaced. Many of the replacement springs on the market do not have the same properties as the original. Not having the same properties as the original springs makes the distributor curve not anything like the chart above.
On the 0231.129.022 distributor, one mistake we do not see often, but it has dire consequences, is painting the inside of the distributor. Because the cast iron can rust, some people feel they need to fully paint the distributor. The problem with this is the points get the ground from the distributor body. Paint means the points can’t get a ground and the car will not run.
The sliding plate is another problem area. For many years there was a replacement part on the market. The original sliding plate is made from phenolic and the aftermarket is silicone. The heat from the engine gets into the distributor and curls up the silicone sliding plate. This will stop the distributor from getting full advance or troubles returning to idle.
Porsche cross-reference number
Porsche did not use the Bosch number 0231.129.022 as printed on the black tag, rather they had their own number, 616.602.201.04