Duraspark Distributor Advance Curve

[NATEHAWK]

Just wondering if anyone has every messed wit this before i'll be doin it this weekend here is the link that shows direction on changing the heavier spring for the lighter springs in return will give you more power at lower rpm's.

http://users3.ev1.net/~bmarr/duraspark_ignition_upgrade.htm#credits

[85crownHPP]

I think GL did this and didnt know it

[grandpaslincoln]

I have no working knowledge of teh 351 duraspark distys. It's easy enough to change springs on a 302 points distributor, but it takes a while on the 351 distributor, since you have to take the shaft and everything out to get at the springs.

[turbo2256b]

If you are talking about the Duraspark II the 351 and 302 advance mecinisums are identical. If your converting a roller motor you will need a steel aftermarket gear because of different shaft diameters. For best performance the advance limiting slot will need to be welded for less advance in the distributor and more added to the inital. A lot of messing with and not for the novice. In fact most certified mechanics no little if not nothing of this. LOL annd I cant get a job as a mechanic cuz I am not certified.

[turbo2256b]

The only way to realy zero in the curve is by reading thee timing marks on the spark plugs very time consuming.

[turbo2256b]

minor spring tension adjustments can be made with out dissasembly of the distributor by bending the outer spring anchors through a small square hole in the plate above the advance mechicnesum with a screw driver confused yet. It could be my speelingg.

[Mercmarquis]

I just went through replacing my distributor a few weeks ago. Only they gave me one with the 16L and 21L slots, My old one had the 10L and 15L . The number means how many degrees of advance you will get X2...ie: 16L means 32* of advance 20L means 40*. Usually with a modded motor you want the lower numbers like the 10L or 15L arms so you can run a higher initial timing for better low rpm performance. So I changed out the arms, you need to take the plate with the pickup off and vac advance off first. The vac advance has a little e clip that need to be pulled out so you can access the screw to take off the plate. If you are swapping the reluctor arms, there is a little clip at the top of the shaft you need to pull out to remove the arm along with the springs.

You can also do what turbo2256 said and bend the spring anchors in to release some tension on it to bring in the advance quicker, you want full advance in around 3000-3500rpm.

Most 302's do good with around 40* total timing that have a few mods(give or take 2-3*). A 351 should be simmilar. If you are using a 10L slot arm, that gives you 20* of advance. So to get 40* total, you need to set your initial around 18-20*. To check this, set your initial first and adjust the carb to run good, then with the timing light on bring up your rpms and keep looking at it and see what your total comes out to be. If it checks out ok, take the car for a test drive and see if it pings or runs crappy, then adjust as needed.

Heres a couple good articals that can explain it better than I can.

http://www.fordmuscle.com/archives/2000/03/timing/

http://www.carbdford.com/viewtopic.php?t=5543

http://www.carbdford.com/viewtopic.php?t=5392 thats the best imo

[Mercmarquis]

also if you are going to pull of the breaker plate you need to take off the reluctor(funny star lookin thing that triggers the pickup) Dont pry on the outter teeth or it will break, pry close to the shaft. There is a roll pin, be carefull not to lose it too.

[Grand Marquis GT]

Pete, how does your car run with the new dist?

[AOD]

If the springs get too 'light' at low speed you'll run the risk of knocking because the timing is too far advanced.

[Grand Marquis GT]

If the springs get too 'light' at low speed you'll run the risk of knocking because the timing is too far advanced.

Yeah... You want full advance at around 2500-2800 for best streetability...

[Mercmarquis]

Pete, how does your car run with the new dist?

Runs friggin awesome! It accually gives me the 20* of advance it should. Before I was running the 10L and had my inital set at like 7* but was still pulling 42* total timing it was definetly not right. It got rid of that bog I had off the line, but its still slow off the line. I need gears and a torque converter to really get the best outta it. I gotta try my vac advance but for now it runs good without it.

[NATEHAWK]

So you guys think i should just try and bend back the tabs a lil bit first see how it feel like that? They say they are accesible thur a lil square shaped cut out in the plate

[Mercmarquis]

It wont do too much I dont think but its easy to do, you'll need a flashlight and you will need to turn the motor over till the spring tabs can be accesed through the hole, while you are looking down there take a look to see what reluctor arms you have, should be a number followed by a L. You'll prolly feel some more power, and the car may drive better.

[Grand Marquis GT]

Glad to hear, mang!

I had a funny feeling it was the disty...