I've replaced the entire distributor, rotor, new plugs and wires, new resistor coil and still my rotor and points continue to carbonize. Any ideas why?
Here is some info to think about. Points will burn over time no matter what is done but the condenser is there to minimize this. If it is open or too small in capacitance value, the point gap will burn at a faster rate. What happens to cause the arc burn is the coil passes current to built up it's magnetic charge. When the cam opens the points, the magnetic field in the coil collapses cause the secondary spark to the plugs and also causes the arc at the points. The condenser is accross the points to absorb the back voltage at the time they open. The rotor and plug tower errosion you see is the spark melting the metal each time and cannot be stopped but only minimized by selection of parts with harder metals. Sometimes the air inside the cap while the engine is running is subject to oil vapors that can conribute to the errosion of both the points and the cap/rotor. Late model large cap distributors have a vent to help this problem. Make sure the condenser is good and you use the best cap and rotor. Plug wires are not to high in resistance. It's somewhat like arc welding. If the arc is drawn out to far, the metal and the rod burns too fast and less controllable..
Is the parts for a duraspark conversion available at a normal parts store? If not any idea where to get them?
About any parts store sells remanufactured distributors. Just ask for a late 70's early 80's something with a 302. As far as I know they are all the same from 74 to 84?. There is a 3 plug and a 2 plug electronic control box. I've only seen very few 3 plug boxes. I'm not sure what the third plug was for. Everything I have ever owned or converted used the 2 plug version. Electronic control boxes are about $20 at the parts store. Do a search on the forum. I think Mavaholic did a how-to article on how to wire things. Pretty simple - just run a new power supply wire to the coil to bypass the resistance wire and you are good to go. Cleaver
If you want to convert from points to electronic ignition just use a Pertronix Ignitor I or II or the Crane XR-I conversion kit (has built in rev limiter)
