Hot Rods Round coil with low ohms

Does anyone have a napa number for a round style coil with.5 or less ohms for hei? I would like something that's traditional looking but can use with my small cap hei. Must be 12v.

 

anyone?

 

Check the coils for Pertronix ignitions.

 

I've been using an Oreilys 2-5195 as recommended by ignitionman on other forums.

http://www.chevytalk.org/fusionbb/s...st/2368049/hl/hei,+coil/fromsearch/1/#2368049

 

What are you going to use to power the coil?

 

We make both .6Ω coils and .32Ω coils
http://www.summitracing.com/parts/pnx-45011
http://www.summitracing.com/parts/pnx-44011

 

Bump

 

I'm using one of the small cap hei distributors. I don't like the big hei at all. But you need a coil with.5 ohms or less for the hei to work correctly.

 

And you know this how? Most 'standard' coils are in the 1.5 to 3 ohm range, going lower increases the current to the coil and is harder on the module. Generally, a lower primary resistance translates into more spark energy, but actual coil size and modern coil design has largely reduced the differences. I know GM HEI modules will work with higher-resistance coils because I've seen them successfully used that way. One issue with the GM design is because the coil is so small, high current is needed (also creating heat) to get enough core saturation. A more efficient coil design can have the same spark output with lower primary current.

 

According to our resident expert GMCBubba, " Now the HEI module WILL run the engine with a higher resistance older coil (1.5; Oreilys 2-5195), however without the lower resistance ( .5) the current limiting circuit wont be reached and the ignition current will be much lower than the 5.5 amps of the .5 ohm coil..and the spark out put will be much lower than it could be..."

I believe GMCBubba sells an epoxy ignition coil made by Andover (USA Made) that is in the .35 to .5 range; however, this doesn't answer your question if you are looking for a coil that you can pick up locally (NAPA). You may check some 6 volt coils as they had very low ohms.

 

I also was going off what bubba had recommended for coils. Will the 6v coil live on 12 volts?

 

I have been told that 6 volt coils "don't know the difference"; however, I have never tried it.

 

If they 'don't know the difference', how surprised are they when they extract their tar insulation from under their sealed caps?
12 volts to a 6 volt coil is akin to sending them to the electric chair, without due process.
I'm for a fair trial.

 

That 'current limiting' circuit sounds su****iously like 'dwell control' which is pretty common on 'newer' electronic ignitions. There's a couple of reasons it's used, but one of the main ones is it allows a smaller/cheaper-to-build coil to be used without compromising output or reliability. The theory goes like this; you design the coil to give the desired output at max RPM, making it just robust enough to withstand the heat generated given the 'on' time at that RPM. At lower speeds, the 'on' time increases (more time between firing signals), current goes up producing more heat, and the coil fails. The 'dwell control' limits the 'on' time (basically, the coil has the same 'on' time at all RPMs), reducing heat.

I had a fairly long conversation with Tech at Dyna Ignitions about this; this was for a motorcycle, but it still pertains to here. Keep in mind that coil performance isn't limited or defined by just primary resistance and/or turns ratio; core size, the interleaving of the primary/secondary windings, and it's ability to shed heat also play a large role in it's performance. I kind of doubt you'll find a 'off the shelf' OEM replacement coil that will match the characteristics of the HEI coil. I'd check with a specialty manufacturer and follow their recommendations. Don't get hung up on the ohms rating; instead, note that you want the same (or close to) output as the HEI but need to keep the primary current below 5.5 amps.

 

Yes a 6 volt coil with a high amperage power module will give you enough fire to burn a wet dog. Griffin Auto Electric

 

I spoke with Standard Motors Products today. They stated that their UF9 ignition coil has a primary of .37-.45 ohms. This coil came on the following vehicles:

BMW 528i/iA- 6-2788 2.8L SOHC (79 - 81)
BMW All Models- 6-3210 3.2L SOHC (78 - 81)
MERCEDES BENZ 380 SERIES-GAS ENGINE (81 - 81)
PORSCHE 911 Series- 6-3299 3.3L SOHC (86 - 89)
PORSCHE 928-V8-4474 4.5L SOHC (78 - 82)
PORSCHE 928-V8-4664 4.7L SOHC (83 - 84)
VOLVO 760-V6-2849 B28 Series (86 - 86)
DELOREAN DMC 12-V6-2850 2.9L (81 - 83)

I then asked them if they had another coil that was close. They stated that their UF48 ignition coil has a primary of .45 -.57 ohms. This coil came on 1986-1991 BMW 325i.

Hope this information helps.

 

Thanks for your help. I had thought of calling just had not done it. Thanks again!!!

 

I pulled the specs for an HEI coil and wanted to post them. The specific coil I used was a Standard Products DR31. The primary ohms of DR31 are .45 to .55 and secondary ohms of 7000 to 9600 with voltage output of 36,000.

It appears to me that the UF48 canister style ignition coil would work best.