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hi can someone tell me what the best springs and stop bushings to use for this distributer? its a msd part number 8577. i know nothing about how this mechanical advance distributer stuff works and would be great if someone could lean me in the right direction. i have all the other msd stuff aready installed 6al box, blaster 2 coil, 8.5 mm wires, e3 plugs. http://msdignition.com/uploadedFiles...structions.pdf
this should be the link to msd's instruction sheet for this distributer, if anyone that knows about this stuff could look at this and tell me what combination i need that would be greatly appreciated,
Total timing should be ~32-34 degrees BTDC. Depending on your cam, base timing might be anywhere from 10 to 18 degrees BTDC (I've got a 292 cam in a Mustang and I'm running 16-17 degrees base timing). Assuming a stockish engine running the usual 10-12 degrees, use a 20 or 24 degree bushing.
For the springs, you'll need a good dial back timing light (unless the timing marks on your damper go up to 40 degrees) and a tach. Mechanical advance should be all in by 3,500 rpm. If it's not all in at 3,500 swap in a lighter spring on one side and try again. If still not, put a lighter spring on the other side. If it's all in before 3,500 you need a heavier spring.
Again, it depends on the engine but it's probably pretty close out of the box. Try it before you start swapping out stuff.
ok thanks, which one of the graphs would be the one with all in by 3500? and what rpm should i put the stop bushing at? sorry for my stupidity about this but its just so much info to take in lol.
my truck has headers, cam (not shure how big), holley 750 double pumper, d3ve heads not shure if all that makes a difference or not but i just want to do this rite the first (or second) time lol. but thanks
also what should the base and total timing be for the most power? i heard that ford made the timing for fuel economy and that it could be ajusted for more power is this true?
i guess what im tryin to say is what causes what. more advance =more ping but more power?, or closer to tdc = more power? what is the cause and effect of retard and advance? i think that would help me understand better.
thanks, brad
There is really no good awnser to any of these questions because every vehicle is different. Initial timing only matters to get the vehicle started, total timing should be between 32-36 degrees and from there you work with the springs and weights for your curve, like they said you need a good dial back or digital timing light to see where you come all in at. You want more advance as it gives you the most power, but ping is hell on a motor.Start at like 10 degrees and then rev it up(vacuum advance disconnected and plugged.) and see what rpm it stops, lets say 4500 rpms is when it hits 36 degrees. You would technically have 26 degrees worth of mechanical advance ie 26+10=36. So if you need 34 you need to change the mechanical to 34 degrees. And try one lighter spring than what is already in there. Next if it is at 3500 then you know the springs are good, then you just have to work on exactly how much timing you exactly need. If your vehicle can handle more at initial then the better. At that point you may or may not need to change the stops inside the distributor. It is all about finding the combination for your engine. I usually set about 13-15 degrees initial and find my total mechanical needs.
does anyone have a chart for the stock ditributer advance also? and also should a stock vaccum advance distributer hose be hooked to the carb or to the top of the intake manifold?
My power band is up to 5500, but that doesnt relate to timing and advance, you always want your timing to come in faster as it is needed to burn the fuel sooner as engine rpm rises. You also want your vacuum advance hose to be hooked up to the ported side of the carbuerator, no vacuum at idle port
ok some good and ok news lol. i got my distributer on and working and all and it runs pretty good now but i think it still needs ajustment. i called msd tech and he said to start with two blue springs and blue bushing. well i put em in and it ran very well especially at low rpm. i had the idle timing set to just before its hard to turn over. well anyway i didnt notice any ping so then i changed to the two lightest spings and it also ran pretty good. but i think not as good as the blue springs at low rpm. anyway i took a trip to walmart and it was runnin a bit weird so i changed back to the blue springs and drove again. it has excellent power low end with the blue srings but past 3000rpm or so, it has a little less power than before i think? what should i do from here? i didnt hear any ping but being that i have straight pipes idk. initial was set at 29 btdc and total couldent be read because of the fact that my harmonic balancer only goes to 30 so idk what to do. i cant afford a dial back light but i did buy a standard timing light to set initial with. any ideas of what to do from here?
Initial timing is at 29 btdc? Are you reading this with the vacuum advance plugged in? You should be unplugging that, it will mess you all up when checking the timing.