Just want some other guys input on ignition coils. I need a new one for my 1978 400 engine. was looking in summits catalog and there are so many choices in coils but all seem so alike. What brand / type are you guys running? Mainly just a street application here no racing rpms but will be running the OEM Duraspark II distributor, so mainly stock ignition. Am just looking for a coil with a little more hotter spark capacity than stock coil. Any suggestions? thanks!

 

I swear by Accel coils. Just be sure to upgrade your spark plug wires too.

 

If you're just running the stock duraspark II ignition a high performance coil alone won't do much for you unless the rest of the ignition system is upgraded as well, from what you described a $20 coil from NAPA will suit your needs just fine, no real need to fork over the extra cash on a hi-po coil.

 

Performance coils are hooplah. For a given plug gap, there is a specific voltage to make electricity arc the gap. Any less, the spark will not jump. Any more, and the plugs will burn up. There is no "hotter" spark, just higher firing voltage which is (a) hard on the spark plugs and (b) a waste, since the factory setup produces enough spark to ignite the air\fuel mixture.

As a side note - secondary coil voltage (the voltage that actually jumps the plug gap) is a function of the primary voltage coil (positive coil terminal) and the ratio of turns in the windings inside the coil. If you use a "hotter" coil which has a higher turn ratio and hence a higher secondary voltage, but you hold the primary coil voltage the same, the coil draws more current. This places higher strain on the Duraspark module as it grounds the coil during the "charge" time each fire. More coil current = more heat dissipated through the module's power transistor = sooner module failure.

Some gains can be seen if a high performance coil is part of an entire ignition system upgrade, but a coil alone is worthless. I personally think that high performance ignition systems in general aren't worth the money, but that's just me. The stock coil does a great job. My 2 cents...

 

thanks guys for the input! fmc400 i found an accel coil in summits catalog that is made for the duraspark system - think i'll give it a try. thanks for the information

 

Good points! Although the ds II box just controls the firing, hotter coils do make a difference, IMHO. Usually if you have a weak coil, and add a better one(stock or better), it should run smoother and better.
I have to run a good ignition, because propane is hard to light, vrs. gas-which is liquid, even vaporized-will ionize and therefore jump the gap easier.
Talk to your local parts guys, you may find a replacement stock looking coil, that is a bit hotter, for the same money-ya never know!
If your all stock, keep it stock and save money for other things. I do suggest looking into some Accel 8.8mm wires, they look nice and work well, plus decent price. Last set of 8.8's I bought the parts guy was surprised at how thick the wires were, and have nice thick boots-worst part is most wire loom holders aren't meant for thicker wires!
So be warned-mind your wire holders or whatever you want to call em-so you don't cut your brand new ign. wires on a 10 cent holder! Been there done that.
I have run holley's cdi setup-returned it(had the brain box cab mounted-sounded like a damn 2 stroke buzzing), ran a msd 6al and all the goodies-it died. Now I run a stock big cap ds2 cap and rotor, some accel 8.8's with stock heat range plugs(gapped at .030 for lpg) with an msd blaster tfi coil, all triggered by an old junkyard gm hei module(it is hidden well) and it works great!
Lasted longer than the MSD, doesn't have the problems that something like the DUI -chevy dist. has(arcing messes up the advance weights-making them stick, and problems with the center electrode in that huge crappy cap) and the price is alot cheaper.
Btw-I use a gm hei module because they have a variable dwell, which senses load and compensates-more voltage, vrs. the Ford DS setup, which has a fixed dwell.

Try a search on gm hei upgrade-on the net-alot of info, maybe not Ford stuff, but jeepers like it too.
My 429 looks stock, except the thicker wires, large cap, and newer Ford type coil, and fires up no problem, whatever conditions.
Don't buy the most expensive stuff-especially wires, or cheap stuff, try to stay middle of the road, should last a few years of happy never fail operation. Get what ya pay for!

 

I just installed the Accel "horseshoe" coil last week along with the Summit multi-spark ignition box. Working well so far. As a precaution I did make up a jumper to bypass the multi-spark box in case it dies, and I always carry a spare dura spark box under my seat.

 

Although we are in the performance ignition business, we would like to respectfully respond to your post:

1) Performance coils are not hooplah, IF they perform as they are advertised.

2) If a coil is designed to jump a wider gap, it will burn your fuel more completely. Of course, as you stated, they must be strong enough to do so to benefit.

3) We strongly agree with you that on a Duraspark ignition system, that the electronics in the coil and module should be "matched" to work together, not only to insure durability, bu also to maximize perfomance.

Performance Distributors - High Performance and Racing Ignition Systems

 

The coil on my 79 TS went out and I replaced it with a MSD Blaster 11.no problems here