Hard core ignition


Well-known member
Who knows something?

Anyone ever replace the condensor with a diode clamp to prevent back emf across the points?

How much amperage will a Duraspark switch? How much amperage do Dura I, Dura II, and TFI coils take? What are the turn ratios on them?

How many amps does a TFI module switch?

What's the difference between grommets?

Blue - Standard, spark retard, fixed dwell?
Yellow - Dual economy/altitude adjustments
Red - Auto sensing dwell, California?

What's the minimum voltage a Duraspark will run at? TFI?

Anyone ever open up a Duraspark?

I know about Pertronix and heard bad things, AND I've had bad personal experience were the battery was weak and the engine would turn over, but not start.

So who's a guru?
Check my post about the DuraSpark for some answers.
Ford says that the DuraSpark I runs down to 9 volts, the II runs down to 7 volts. I don't know about a III.
I'm curious why you want to run duraspark. There are many high performance aftermarket ignitions available. Personally I'm running MSD ignition products due to the fact that their spec are so tight. If one ignition box in a batch is bad they scrap the whole batch. And they last longer than factory stuff. IMHO
In defense of those of us using duraspark: How about $15 for a duraspark module versus $150 for an MSD?? I bought a brand new distributor, cap, rotor, wires and module for about the cost of the MSD box alone. While I'm sure the punch from the MSD is nice, the improvement I experienced over the stock points ingition was monumental.
MSD vs DuraSpark? Night and day! Stock ignitions cannot compete with aftermarket systems so the comparison is irrelavent. Your point is good however and well taken. Stock type ignitions are cheap. but remember, you get what you pay for ;)
8) before you knock the Dll, realize that the system is virtually bulletproof. my 80 pinto had an engine fire while in the care of a po, and the ignition never missed a beat even though the connectors were badly burned and never replaced.
No offense intended guys. I''m just saying that the stock ignitions leave much room for improvement. Granted DuraSpark is a step up from points, but aftermarket companies such as MSD and Jacobs, etc. have put way more R&D money into ignition setups than any car manufacturer and can provide better spark, multiple spark and longer duration than stock systems. I'm not saying that they don't work I'm saying that aftermarket is just plain better. So if a guy is going to spend the money to build his engine using the bast parts out there why not step up to a better ignition as well? That's just my opinion.
Why I want to run Duraspark and what not is that I want a cheap, easily available (stock) system. I want to know what components that you could mix and match to provide the best system. I heard putting TFI coils on Duraspark systems are better, but might burn out modules....I've heard of running TFI modules with points, etc. I have spare parts laying around, and I don't want to spend money of some aftermarket system when I have junk around or can get for free....So that's why I want technical info on the stuff....
It really all depends on what your goal is. Unless you are spending some heavy coin on building a serious performance engine, it's doubtful that you will notice the difference between Duraspark and MSD. On a serious race engine, the MSD is a relatively small percentage of the total investment. On a mild street engine, you would need a dyno to tell the difference. You will get more bang for the buck out of something that helps the engine breath better, as that is the weak point in these engines. Is MSD better? Yes. Is it worth it? Only you can decide that. JMHO
Lazy JW
Actually you notice the difference between aftermarket and stock at first start. The difference is so great you can't help but notice it. I understand now why some people are looking into stock parts but if you want parts, that was my only question. The way I see it is if you want cheap go stock, if you want parts availability use dark side parts(Chevy), but if you want serious performance use aftermarket, whatever the brand ;)
Well what about the HEI? I know I've seen it works with the Duraspark dizzy...but I want the info

How many amps does HEI switch vs Blue Grommet?

Is HEI automatic dwell? Is Blue Grommet?

What's the turns ratio on coils? Primary resistance? HEI coils, duraspark coils, aftermarket coils...

If I see the numbers, then the truth comes out as opposed to "yeah it's better", which I'm sure for different applications it is....The biggest advantage I have seen from aftermarket is the second spark stuff.

I also want to modify some of the newer components to work with 6 volt systems. What's the real difference between a 6 volt and 12 volt coil? Will modules run on 5 volts?

I'm not building a racer, just a street, and I have more patience than money. Why shell out $200 when I can shell out nothing and have a system 75% as good?
You asked for numbers so I will supply them. This is a taste of what the aftermarket holds, it was copied from the MSD website ;) If you want more try http://www.msdignition.com/

Operating Voltage: +10-18 VDC Negative Ground
Current Requirements: 5 Amps-5,000 RPM
10 Amps-10,000 RPM
RPM Range: 15,000 RPM with 14.4 Volts
Spark Duration: 20° Crankshaft Rotation
Energy Output Max: 105-115 mJ Per Spark
Weight and Size: 3 lbs, 8"Lx3.5"Wx2.25"H
Voltage Output Max: Primary: 460-480 Volts
Secondary: 45,000 Volts (Blaster Coil)

Primary Resistance: .355 ohms
Peak Current: 300mA
Secondary Resistance: 6.2K ohms
Spark Duration: 180uS
Maximum Voltage: 48,000 volts
Primary Inductance:
Turns Ratio:
70:1 Tested with an MSD 6AL
measured at plug gap.

Maybe MarkP has more info for you on stock stuff. I just know stats on aftermarket goodies. But if you already have a pile of stock stuff by all means use it. Why let good parts go to waste? I plan on shelving my stock parts just in case I do need a backup system. Later gents.