Hi all !
Need a little help getting rid of the duraspark ignition on my 1976 460.
I'm getting rid of the emissions system and would like to simplify the ignition.
Can the duraspark be bypassed and just go from the distributor to the coil? Would I need a different distibutor?
Thanks for the help!
john460

 

> Need a little help getting rid of the duraspark ignition on my 1976 460.

Basically, buy a coil for an older truck, get one that takes 12v and drops it to 9. Cost about $10 from Autozone. Unless you want to add a ballast resistor and two separate circuits. Seems like too much hassle that way.

Get a single vaccum advance distributor for the same older truck for points. Cost $30 plus core from Autozone. Might have to recurve it with a spring set from Summit. I think one from a 351m 1973-79 should fit your 460. Hook up the coil to a 12v source with ign. on. You might be able to get one for a 460.

That is about it except normal install stuff.

Might want to add the Pertronix later to replace the points.

Most Duraspark (dead) issues are from bad harnesses and overheating. Moving the box so it receives better airflow and away from the exhaust manifold helps a lot. fwiw.

 

rebocardo,
Thanks alot for your help!
let me ask you this, do I gain anything from keeping the duraspark ignition?

 

Hotter spark, reliability, lower maintenance...

Why are you wanting to ditch the Duraspark system?

 

I guess I'm not understanding what it does. Do you need this to run the ingition? I thought you could just go from dist. to coil, or would that be how the older dist. worked with points?

 

To make a spark to jump the sparkplug gaps, you need the coil to raise the voltage from 9 volts to a few thousand volts.

The coil is just a transformer. But it will not work on DC voltage. It must be turned on and off for the voltage to be transferred to the plugs.

The points in the old style distributors turned the voltage on and off, making the coil fire. They where mechanical, so the plastic piece that rode on the cam wore down, as well as the points themselves wore down from arcing. The gap on the points is critical for proper operation, and is always changing because of wear. Replace the points every once and awhile and they work ok.

The duraspark II does the same job as the points. Instead of a cam with 8 lobes, it has a star wheel with 8 blades. This triggers a pick-up sensor, which tells the duraspark box when to switch the coil on and off. The duraspark box on the fender has a large transistor that switches the current instead of the points. It is solid state, so it never wears out. The dwell(gap on the old points system) never changes, and there is no arcing of the contacts. So there is no maintenance. The electronics also allow the system to give a higher voltage spark. And they have included a feature on most duraspark boxes that retards the engine timing a little bit when starting. This makes the engine easier to turn, so there is less load on the starter.

It's a good system, but if you put an earlier dist out of a 351c, or a 429 with points, it will work too. I don't know if they made a 460 with points dist, but the others will fit fine, and they where early engines with points.

 

I think you would be foolish to revert that ignition system back to points

 

Ok, got it.
Thank ya'll for the help.
I'm glad I came to this site.
Till next time...

 

I would definitely not revert to points, if anything you could upgrade to MSD or some other brand. I know some folks here like th the OEM duraspark and I'll admit it's done it's job reliably but I wanted more for my 460 so I went to the MSD Offroad (basically a waterproof, vibration resistant version of the msd 6). but here's the trick, it comes with GM style waterproof connectors so I went to the local parts store and got a duplicate set of connectors and put em on the duraspark stuff so now when I go wheeling I have a better spark ( and YES, it is better than the duraspark) and if it fails I can fully revert to the durapark in 15 minutes, it would only be 2 minutes if I kept the duraspark unit mounted. It's a few bucks to spend but man it helps big time. And if your really concerned about reliability you can find NASCAR style dual ignition box mounts and get two boxes, two coils, and the odds and ends like a switch... voila, foolproof ignition!!! (aka maximum overkill)

 

Thanks ST_Wilson for the good info! I'm convienced.

 

The MSD system is not any better than the Duraspark until you get over 5500 RPM. Dyno tests have shown that it is no better or even a little worse under that RPM. Stick with the duraspark II system. Carry a spare module if required. Mount the module on 1/4" standoffs so air can get under it. Use genuine Motorcraft modules, most of the aftermarket modules are junk (which may explain the differences found in the post above). You can pull Motorcraft modules in the junkyard and have them tested at a parts store for free. Funny thing is that I have pulled several and have not found a bad one yet. I have several on the shelf for spares but since I have gone to Motorcraft I have not had a failure.

 

Torque, your exactly who I had in mind when I said some folks like the duraspark... I gotta tell ya I disagree though and have seen dyno tests that prove exactly the opposite. Plus my truck is proof enough for me, it instantly idled better and pulled harder after the swap so hey, to each their own. In fact, prior to 3000 rpm the msd units provide multiple sparks to get a fuller burn, at 3000 rpm it rolls over to a single spark.

 

I have the duraspark I. is this ok? should I chance it to the duraspark II ?