Just got a Duraspark distributor from the wrecking yard and there's a fair bit of crud in it that I'd like to clean out. Is there an easy way to get the roll pin out that holds the armature on the shaft? Also my original distributor has two vacuum ports and the Duraspark only has one. So am I interpreting correctly that a person can just connect one vacuum line between the carb and distributor, and plug the other port on the intake?
Yes, you can just plug the extra port. Make sure you use the timed port vacuum connection and not full manifold vacuum...
Thanks T.L. As for my other question, perhaps I need to rephrase it. It appears to me that the armature needs to be removed in order to remove the other parts (base plate etc.) to clean them. The Chilton manual I have shows an exploded view of a disassembled V-8 breakerless distributor but doesn't explain how to disassemble it. Has anyone had any experience taking one of these units apart?
Duraspark Has been a long time since I did one but Mavman has done some lately, if I remember you just pull the armature off the shaft. The roll pin will come with it, then replace it and insert roll pin into slot. The boys do this regularly to remove or replace advance springs. Removing one of the springs allows almost instantaious advance, this depends a lot on cam, manifold, carb, and compression ratio, on what way to go. By the way after you have gotten into one of these you will notice they are the exact same thing as a MSD internally. The MSD uses a billet housing with bearing etc. Love the MSD's but also ran a mdified Duraspark for years with great success on mild rpm engines(6500rpm). Check me out Mavman and add any other tips for the Maplemav. Sometimes I get a brain fart and get it all screwed up
a cheezy page I created for some Duraspark information:http://www.geocities.com/mavman687/distributor1.htm Yes, they're great distributors, just not as easy to work on as other aftermarket brands as far as tuning goes. Pretty simple design, however and easy to disassemble for cleaning, etc.
Wow that's awesome! Thanks Mavman and Old Guy. My distributor body looks slightly different from yours, Mavman, but probably I guess just due to the fact that the 6 and 8 cylinder models are slightly different in general. In any case this will be of great help to me. This may be a stupid question but how does one determine how much advance is appropriate?
Ignition Advance As a rule of thumb, the initial and total advance settings are determined by several things. Cam specs, compression ratio, fuel grade used etc. In your case go with the factory settings, old days we would twist that distributor until the engine cranked like it had 14 to 1 compression, then back it off a little. Another indicator would be loud pinging sounds from engine when accellerating rapidly. Too much timing will result in various stages of engine distruction etc. Have put a lot of timing into my race car and it felt strong, but for testing, retarded a few degrees and low and behold, it ran faster. Factory engines were tested and timing numbers were determined by the engineers for best performance. The new cars have just about solved the problem with computer controlled spark sequence's and such. Sorry about rambling on but thats what old guys do sometimes.
