Coil questions: What ignition coil works best?

GaryMB · #1 (**permalink**) 04-15-2005, 05:48 PM

OK, I've been doing some research and am almost done with my TFI swap but do not know where to go from here. One thing to keep in mind is that I have no resistor going to my coil right now, so it gets a constant 12v. Here is everything I am considering:
1. I bought a stock ford tfi coil for $40. It is unused and still capable of being returned.
2. I saw an MSD GM blaster coil part number 8226 at pep boys for $38. It supposedly puts out 48,000 volts and I believe is oil-filled.
3. I saw an MSD blaster TFI coil part number 8227 at pep boys for $44. I believe that this one is also oil-filled and puts out 48,000 volts.
4. Any other ideas?
So what is the difference between the ford tfi coil and msd blaster coil? Is oil filled better? Also, will any of these coils withstand a constant 12 volts? Are there any other parts that will fail when given a constant 12v? Do I need to buy a resistor? I really could use some help here...my jeep is sitting in the garage just waiting to be finished.

laneiac · #2 (**permalink**) 04-15-2005, 07:18 PM

I asked a similar question about an MSD for my YJ sometime ago. Never got a response, even after bumping. So, I hope someone is kind enough to answer you.
My money would be on the MSD, just due to reputation. But I might be wrong.

GaryMB · #3 (**permalink**) 04-15-2005, 11:16 PM

I just did some more research and it looks like the msd blaster tfi is epoxy filled just like the ford tfi. Tomorrow I'll return the ford tfi and get an msd blaster tfi.

jay79cj7 · #4 (**permalink**) 04-16-2005, 12:06 AM

I think I already replied to you that I burned a TFI coil using it with 12V. It stopped working and folks here told me that was why. By the way, I think I paid half what you paid for the TFI coil.

Inspector-Gadget · #5 (**permalink**) 04-16-2005, 11:10 AM

Hi-Ya GaryMB,

Assuming you are asking about ignition coils for the 84 CJ-7, I-6 mentioned in your sig, I would ask you to consider an alternative ignition system modification: the GM HEI distributor mod.

One junkyard GM 1st generation HEI distributor........$~20.00
One set of Ford Fairlane I-6, 8mm sparkplug wires....$~14.00
One distributor drive gear......................................... $~15.00

Total cost...$~49.00

Very roughly ... 1-hour installation time

Advantages:

Eliminates the failure-prone OEM ignition module
One wire hookup of the HEI
Easy installation of a hidden kill/anti-theft switch
Engine now easily revs to 4,000+ RPM
Flawless ignition system performance for the preceding 2 years.

Works for me and the Bubbacon.

Regards,

HEI-guy Gadget

PS-1: This post should not construed as an argument against any of the several available after-market ignition systems and/or mods. Not going there -- I am merely attempting to serve-up food (meatloaf!) for thought.

PS-2: There several web articles about the HEI-mod. A "Google" search will locate them for you.

PS-3: Consider any possible down-the-trail implications of ignition system mods as regards vehicle smog-law inspection as those inspections are implemented where you live.

GaryMB · #6 (**permalink**) 04-16-2005, 11:37 AM

Well, I actually have a GM HEI sitting on my work bench that I had to remove to pass smog. The reason I was converting to TFI and not back to the hei is to stay smog legal, but then again if the switch is only an hour I could easily just switch back before the next smog test. What I'm concerned about though is if the smog system will be impaired when the distributor is left out of the loop. I really don't want to replace the catalytic converter again, and have no idea if switching to an hei will plug it up. Would it be possible to bypass the ignition module with the TFI/duraspark, and just reconnect a few wires to include the ignition module again?

derff96963 · #7 (**permalink**) 04-16-2005, 04:09 PM

If you still want to know about coils, you really need to get a resistor for the coil no matter what coil you use. I had fried 4 ignition modules before I put a simple balast resistor in, still I burn out the points of the dist cap about every 200 miles. After 200 miles it looks like it been on for 40,000 miles. Its runs great for the 200 miles but I am getting tired of replacing the dist. cap all the time. I need to get ahold of some of the resistance wire that is supposed to be there.

Inspector-Gadget · #8 (**permalink**) 04-16-2005, 10:23 PM

GaryMB wrote:

Quote:

I'm concerned about though is if the smog system will be impaired when the distributor is left out of the loop. I really don't want to replace the catalytic converter again, and ...

Gary, I cannot answer that question with any certainty, and I wont guess.

Regards,

Stumped Gadget

GaryMB · #9 (**permalink**) 04-17-2005, 10:52 PM

Well, I went with the msd blaster tfi just to be safe. So far so good. I'm having to order a ballast resistor though, so hopefully the coil and cap will hold up to 12v until it gets here.

GaryMB · #10 (**permalink**) 04-17-2005, 11:30 PM

Should I get a ballast resistor for a ford or a jeep?

jay79cj7 · #11 (**permalink**) 04-17-2005, 11:51 PM

I just put a painless kit in my CJ and it came with a ballast resistor. I have no idea what its from, but I am curious myself for replacement purposes. You could give painless a call, they have a 800 number. That way you know you are using the right part for the job. If you find out, let me know!

Ritt · #12 (**permalink**) 04-18-2005, 10:29 AM

I'm surprised no one has mentioned Pertronix ( http://www.vintageperformance.com/re...ts/ignitor.htm ) Lots of the Willys people have made this switch but I don't know anything about later CJs. I converted to 12V from 6V and have to use a ballast resistor or you'll burn the points. Some coils have an internal ballast resistor.