cap and rotor questions

[pjc360]

Ok first off let me start by asking, what in the world be going on to cause the chrome prong on the rotor in my distributer to be smashed flat down like a pancake and be black? there is also brass looking debree on the rotor that came from the brass buttons inside the cap, also the inside of the cap is black and worn down to nothing, what is causing this? this happed once before and i chalked it up to being the wrong distributer cap and rotor and i thought i got the correct cap and rotor this last time, but same thing is happening. Does anybody know off the top of there head some part numbers for a cap and rotor for a mopar electronic distributer with vaccume advance?

 

[pjc360]

Oh sorry i forgot to add a mopar electronic distributer with vaccume advance on a small block 360 magnum. the cap i had on that is now totally ruined was a napa echlin part number M020 and i cant remember what the part number to the rotor was but it was also an echlin.

 

[pishta]

are you sure you got the cap in the little locating tang by the vacuum advance bracket? If it is cocked and clamped down, your rotor may contact your brass contacts, and miss others completely. When that happens, or when you get a high resistance hit, it burns your button because 20,000 volts has no where to go. So I would make sure you get the correct cap (huge year run on these, nothing special) and rotor AND make sure the cap is seated properly on the distributor body.

 

[67Dart273]

Well as they say, "we need picchures"

If we can see the damage both to the cap and rotor, that might be a clue.

It appears that M-020 is correct.

Might be something wrong, like.....look down in the hollow top of the top shaft. Use a sharp tool to dig out the felt washer (which is sometimes missing) and use a small light to determine if there's a snap ring in there. Pull up on the shaft, does it seem to have excessive up/ down play?

How about the main shaft, does it have any vertical play?

How about the fit of the rotor on the shaft, does it fit down completely on the shaft? If this is a new dist, might be that the keyway is not deep enough, or has a burr which is preventing seating of the rotor.

Cap, does it fit down square on the rim of the housing, with almost no play or "wiggle?"

 

[cudamark]

Well as they say, "we need picchures"

If we can see the damage both to the cap and rotor, that might be a clue.

It appears that M-020 is correct.

Might be something wrong, like.....look down in the hollow top of the top shaft. Use a sharp tool to dig out the felt washer (which is sometimes missing) and use a small light to determine if there's a snap ring in there. Pull up on the shaft, does it seem to have excessive up/ down play?

How about the main shaft, does it have any vertical play?

How about the fit of the rotor on the shaft, does it fit down completely on the shaft? If this is a new dist, might be that the keyway is not deep enough, or has a burr which is preventing seating of the rotor.

Cap, does it fit down square on the rim of the housing, with almost no play or "wiggle?"

X2. The mashed center button is usually not seating the rotor all the way down or the center shaft in the distributor has too much verticle movement. The damage to the wire terminals in the cap are the result of the rotor tip contacting them. If all of them are damaged, the rotor is too long or the shaft is bent. If it's just hitting one side, the cap is on crooked.