pparaska Posted October 3, 2002 Share Posted October 3, 2002 O.k. My motor is sick (burns a qt every 500 miles) and the plugs get a bit fouled (getting better). But every time I pull the rotor cap, after replacing it 3-500 miles earlier, there is all kinds of carbon tracks on the underside all over the middle and the sides, marks on the weights and center post next to the weights, etc. I can't SEE any burn through holes, but there is definitely arcing going on. I know some rotors are better than other. I've tried NAPA, and others, but I'm wondering if the 45000 Volt coil (Accel Brute Thunder) in the cap is just too much. The wires measure down in the 10s of ohms (MSD 8.5), and I've tried resistor and non-resistor plugs. The plugs are pretty clean on the electrodes, etc., so they're not fouling causing this. The mark on the cap terminals on the inside of the cap have a small dot where you can see the spark is jumping from the rotor tip to the terminal. It's near, but not at one side of the terminal. Should I worry about this? Do I need a less powerful coil? Any leads on a rotor with thicker plastic, or plastic with higher dielectric strength? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted October 3, 2002 Share Posted October 3, 2002 Pete, Just a thought: Have you checked that the installed height of the distributor is correct (ie, does the contact between dist. base and inlet manifold need to be shimmed). I remember when I installed a HEI in my truck with the new Edelbrock (Vortec) manifold I didn't check the freeplay on the dizzy shaft and it ended up grinding away the cap. (needed significant shimming) Tim Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 3, 2002 Author Share Posted October 3, 2002 Yeah, I was pretty careful to check that, and one gasket under the distrib housing was enough to provide some vertical play in the shaft when the housing was tighted down. Thanks for the idea, though! Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted October 3, 2002 Share Posted October 3, 2002 Your still having that problem? Accel rotors are much thicker than OEM rotors, not sure if that would help. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 3, 2002 Author Share Posted October 3, 2002 Thanks, Mike. Need to stop by the speed shop and get one of those. I'm wondering if the plastic used on the different rotors have significantly different dielectric strength. Thicker is better if they are made of the same stuff, but thicker and higher dielectric strength per thickness would be even better. Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 3, 2002 Share Posted October 3, 2002 Usually rotor failures are a cap problem. If the spring and the contact in the cap are not making contact with the center of the rotor then you get arcing everytime the coil fires. Pull your coil (if it is internal) and check the bushing and spring, or go buy a new cap and rotor with brass terminals/contacts. I was NOT happy with the quality of the Accel parts. Either MSD or even Blue Streak is better IMO. (I had an accel cap that destroyed several rotors, the spring clamps were so weak, that when I grabbed second gear hard, the cap wiggled enought to contact the rotor tip, immediately turning it 45 degrees. POW! take the cap off turn it straight, drive home slow, buy another rotor. MSD cap and rotor solved ALL of those problems.) Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 4, 2002 Author Share Posted October 4, 2002 Thanks for the tip, Mike. I'll pull the coil out and see if the spring is contacting the coil well. I know the center contact in the cap is contacting the rotor well, as it wears a nice little circular spot on it. This is one of those CrossFire caps. I'm going to put a regular cap on and see if that might be it also. P.S.: Mike, be looking on the door step for a box from me. Sorry it took so long! Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted October 4, 2002 Share Posted October 4, 2002 Oh Pete. I had a crossfire cap some years ago and the thing gave me nothing but problems. Get a regular cap. I know it will screw up your nicely tailored plug wires, but those crossfires are crap. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 4, 2002 Author Share Posted October 4, 2002 Thanks for giving me great info for the second time today Dave! What problems did you have with the Crossfire? I'll ditch the cap and put the BlueStreak one I have on. I think I have enough wire length to do it. Thanks! Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 4, 2002 Share Posted October 4, 2002 Thanks Pete, I'll be watching! Let us know what you find with the cap. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted October 4, 2002 Share Posted October 4, 2002 With that crossfire, I had random misfires, and then one day lost a cylinder completely. If you look at it, all they have done is use solid wire to cross connect the terminals and pour epoxy over the whole works. I think those solid wires cross talk with each other considering how close they are, the amount of voltage that is going through them and they are unshielded. Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 4, 2002 Share Posted October 4, 2002 Isn't the optispark pretty much setup the same way? Seems like a reasonable idea, but in practice it doesn't seem to work too well. Also makes getting a cap locally a pain in the arse. If you have to buy plug wires, get the ready made wire for a 67-72 GM truck with small block. These have straight boots on the distributor so they don't lay over on each other at the cap and they have 90 degree boots on the other end. They route down the back of the block, along the oil pan and come up to plugs from the bottom. Works quite well, and the ready made wires are actually cheaper than the cut to fit sets which you can't get with straight distributor boots. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 4, 2002 Author Share Posted October 4, 2002 Dave, I haven't had those problems, and I know what you mean about how the cap is made. I saw that when I got it and had reservations. Mike, thanks for the tip about the truck wires. I was just thinking about how to be able to lay the wires over the cap and not being able to do it with the 90 deg HEI boots that come on the univeral set. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted October 5, 2002 Share Posted October 5, 2002 Take a look at the engine pictures on my site for a suggestion on how to run the wires neatly on a conventional cap (not that you, Pete, need any pointers on craftsmanship!). #3 and #2 are the only wires that need to cross sides, and that can be done with nice large loops that swing low under all the other wires. I used the MSD superconductor trim-to-fit set so the lengths can be tailored just right. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 5, 2002 Author Share Posted October 5, 2002 Dave, that looks really good. Neater with the 90 deg boots too. Thanks for the tip. I guess I may be getting a new set of wires (I used the same ones you did). Thanks! Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 11, 2002 Share Posted October 11, 2002 Pete, did you ever solve your rotor probs? Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 11, 2002 Author Share Posted October 11, 2002 No, haven't even touched the Z in a while. Maybe this weekend. Thanks for asking! Quote Link to comment Share on other sites More sharing options...
riverz Posted October 12, 2002 Share Posted October 12, 2002 pete I had the same problem. I went to an accel cap and rotor. the other one i had melted the carbon rod in the center of the cap it took me a while to figure out what was happening because I couldn't see where it was until all the carbon gone. It started in side the cap. I got my cap at shucks, kargen or cecker. depending on what part of the country your are from Quote Link to comment Share on other sites More sharing options...
John C Posted October 13, 2002 Share Posted October 13, 2002 Pete, You wouldn't happen to be using a MSD 6 series ignition box? If so you should be using a high quality non tracking rotor and cap.Install with clean hands. I had the same problem with my LS6 a few years backs.I ended up using a MSD pro billit distributer.(4 years no problems). John C Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 14, 2002 Author Share Posted October 14, 2002 No MSD box yet, John. Thanks for asking. I have one of those low resistance non-carbon center rods in the cap - came with the Brute Thunder coil. Quote Link to comment Share on other sites More sharing options...
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