Thursday, August 30, 2012

235 Distributor Upgrade...

One of the major limiting factors in a Chevy 235 is the ignition.  GM had a very interesting idea of rotating the entire distributor in the block for the vacuum advance.  When the motor rev'd up, it looks as if the distributor is loose.  Also, whenever the oil was changed in the car, the mechanic was suppose to give a quarter turn of the grease cup located on the side of the distributor.  This lubricated the upper bearing and in most cases, never got done.  While they worked for all of those years, most of the time nowadays, they are just plain worn out.  Couple that with the fact that I completely and utterly despise points, you have the bases for a "modern" electronic upgrade.

I say "modern" because you still have to use a distributor that is approaching 30 years old.  1983-1985 Chevy S-10's with a 2.8 V6 still had a carburetor.  This meant that they still had vacuum advance.  After 1985, GM switched to EFI and controlled advanced electronically.  While they look almost the same, 1986 and later dizzy's did not have the vacuum pot.

With a little bit a machining and swapping of the drive gears, now you can have electronic ignition with proper vacuum advance.  The two distributors on the left are modified version of the stock distributor on the right.