I am having a complete brain failure (not just a blip or fart, a failure) and can't remember from my old car if the Dist cap had springs on the screw type mechanism that holds the cap on. The reason I ask is because the cap thats on the GS does NOT have any springs and even when I turn the screw so it should be holding on firmly I can pull the cap off. I figure I need a new cap, but I want to be sure when I get it, I get the right thing. Thanks in advance.
Eric, From the Ignitionman: "Two sources for good quality black caps NAPA RR165, make sure it has copper terminals CarQuest, which is Standard Motor parts, DR429 Rotors have changed, and NAPA is no longer acceptable, poor quality/construction A better rotor is the CarQuest, 23041, CQ RED parts line, Wells manufacture, and the square locating tab must be shortened if you have a trigger conversion of any kind that is close to the pickup. Dave Ray I-Man"
Thanks Larry I will be using the Crane XR-I conversion, which is supposed to be drop in. Do you know off the top of your head if I'll need to shorten the locating tab? I guess I'll find out when I go to put it on. Now to find a CarQuest that is actually open around here :rant:
Never used the Crane XR-1, but it will be painfully obvious if you need to shorten the tab. I doubt it. Take a look at this I-man conversion. You can see how close the rotor mounting tabs(and screws) come to the pickup. The Crane unit is nowhere near the height of the MSD pickup.
Some more from Dave: "Larry, The rotor is actually a Wells part, available from CarQuest as 23041, or from Auto Zone as Wells DR969. Better construction, more dense than NAPA and Standard Motor Parts products, has better di-electric properties as well. With the Crane cponversion, no cutting of the square locator post is needed. Only time the square locator needs to be cut is when a real magnetic pickup, like an MSD, is used and the locator could contact the pickup. Regards, Dave Ray I-Man
from wwwaaayyy back in the memory banks - check the distance between the tip of the contact ( pointer ) on the rotor and the inside cap contact . i seem to remember some magazine articles a long ways back testing that . less gap better , more gap worse . more gap helped emissions but a closer gap gave a little more power . the mags felt that they were changing the gaps to sneak some extra emission benefits in on us with no regard to power output and that some of the mainstream ignition part suppliers were going along with it . i remember they had pics of the differences in the rotor tip length and how to spot the better rotor . may make less difference now with higher output ignition systems . also check some real old spark plug catalogs against some maybe mid - late 70's catalogs , same motor / application listing - different ( hotter ) plug applications sometimes . same theory probably . i saw a champion plug rep give a real nice demonstration one evening at a small seminar about octane and piston pounding ( low octane hammers , better octane pushes ) and also the effects ( heat in relation to combustion chamber metal strength ) of just going up one heat range in plugs . just some thoughts from an old guy . del
Larry: Pass my thanks on to Dave, I would've gone with his conversion but with the other stuff I've gotta do to get it ready for the summer my budget is way tighter than I wanted to. I still have full intentions on getting the conversion done, probably next winter :TU: Del: The instructions mention something along the lines of that as well as the distance between the XR-I module and the shaft in order to increase performance. Right now I'm just trying to get it running and so that it revs over 4000 rpm this summer! Thanks for that explanation :grin:
Dave sent me this: "Larry, There are two different lengths for the tips on GM points style rotors. The longer of the two is early, non-emissions type. these were more for weaker spark used with richer non-lean type engines. The later ones had a bit more tip to conductor length, are designed to work the coil secondary windings harder, to help bridge plug gaps in environments that have less fuel molecules, farther apart, with slightly higher output levels. HEI ended up resolving a dying issue, weaker and weaker mixture light off with points. Usually, aftermarket replacement rotors that are for the later style points distributors are marked with a letter "E", for "Emissions" larger gap. Hope this helps explain it a little better. I-man"
