Low resistance plug wires

[kikkegek]

he guys,

I measured my spark plug wires today and found they are 5 kOhm/ft

I find they pretty high or isnt it?

I am considering swapping them for some 40-50 Ohm/ft wires, because I only run propane and want the best spark I can get.

My ignition is a Delco Remy HEI distributor with in cap coil on a Chevy small block 350 with about 10.5 CR.

Will I benefit from this swap or is it just a loss of money?

[gottago]

Kik...Weren't you running one of those cd black boxes on this engine with the hei dizzy?

[kikkegek]

Kik...Weren't you running one of those cd black boxes on this engine with the hei dizzy?

yes, CB Performance Black Box, why?

[gottago]

There is some ongoing discussion on the programmable ignition thread in regard the black box.
viewtopic.php?f=5&t=1484&start=30

If you had time could you give a bit of an update on your experience with the black box.. As far as how it relates here,I haven't looked into all of what changes the black box makes to an hei setup, but it is a common upgrade for hei to go to the external coil along with a few other relatively inexpensive upgrades. That route seems the best value for the buck with hei. Whether compatable with the black box or not?

[kikkegek]

dude, I started that thread. But I am looking for info on spark plug wires...not the ignition itself

[Steptoe]

No I dont believe u will notice any further advantage changing the HT leads

External coil being a "upgrade" no.. all it does is make cracking a cap less unlikely if dropped...
In 30 yrs the only issues have ever had on a GM hei are , worn shafts (1 set bushes will do 2 shafts) worn counter weight bushes... all other issues trace back to being dropped and similar abuse... OH and issues with the 1st 4 pin modules, of which have not seen one for maybe 25 yrs now.
And surprisingly, the Chinese replacement I got a few yrs back... simply because a Genuine GM unit was not available there and then off the shelf... has/ is proving to be rather reliable , except for the VA diapham... replaced with a aftermarket unit... the available GM units where a little to far off the spec I required even to modify ....

[C3H8]

Back to the original question. Is 5000 ohms per foot high? If they are factory carbon core wires, no. If they were aftermarket low resistant wires to begin with, yes. OEM wires manufactured even on engines with individual coils and short 1 foot wires from GM are still carbon core and brand new they have 3000 to 5000 ohms resistance. Has a lot to do with electrical interference. I prefer the low resistant wires as long as they are properly shielded. I remember buying low resistant wires in the 80's and ending up with all kinds of static on the radio. Newer LR wires are much better shielded.

[kikkegek]

ok, thanks, but my question was....is it worth the money to swap from these 5kOhm wires to 50ohm type wires?

Steptoe already said no. Lets hear some opinions...isnt spark power increased by the lower resistance? and isnt the best spark possible important with propane?

[gottago]

I realize you started the ignition thread kik.. I know you are looking for info on spark plug leads just thought you might update us with your experience with the black box as others are still looking into doing similar. If you had the time..

As far as the hei upgrade for increased spark energy.. loads of info from users who have done that.. Depends on usage and rpm requirements.. One fellow even claimed a couple mile per gal difference..

the NON-computer controlled HEI can be made into a great distributor for a street or street/strip car. Its simple, easy to tune, and plenty powerful to light off any naturally aspirated engine up to 7000 RPMs if properly equipped.
Let's start with the coil. Its located on top of the distributor between the plug wire towers under a plastic cover. It's the "engine" that makes the sparks. Stock its capable of about 35,000 volts and so-so total spark energy. Its fine for a naturally aspirated street motor that rarely sees the high side of 5000 RPMs. It will provide the energy to jump a plug gap of .040-.045 with no problem in these applications.
You can upgrade the coil with an Accell or MSD replacement coil that will jump the voltage up to about 42,000 volts and total spark energy will also jump about 10-15%. There are even hotter coils than this from Accell, MSD and others that will give you the same 42,000 volts but a LOT more total spark energy (like 50% more). Either one of these “super high output” coils is a worthwhile upgrade for a hot street motor- you'll get better response and HP especially at higher RPMs where the stock one hits a kind of "wall". A new coil is also a lot cheaper than a complete MSD ignition amplifier setup and at least 95% as effective at making HP in most naturally aspirated applications (the MSD will still give you slightly better mileage & emissions due to it’s multi-strike spark capability below 3000 RPMs). With either hotter coil you can open the gap up to .045-.050 for just a smidge more HP. There are 2 different versions of the HEI coil and you need to make sure you get the right one. The only external difference is that one has red and white power leads, the other has red and yellow power leads. You will need to know which one of these you have stock to order up the appropriate aftermarket upgraded coil.

[kikkegek]

ok, thanks man. good info

I have no updates on the black box yet, as my rebuild only made it 500km and then the #1 main bearing and #1 rod bearing went out. some dirt must have gotten into it.

I am currently rebuilding, slow proces, little time, waiting for parts. When rebuild, I will start testing again and update.

I looked up the difference in wire color (since I did not know):

The ignition coil is selected based on the pickup coil used. Chevy/Cadillac/Olds Toronado use the yellow-coded pickup coil, so they use the yellow-coded (red and yellow wires) ignition coil. Olds except Toro, Pontiac, Buick use the "Non-Yellow" pickup coil, so they use the "Non-Yellow" (red and white wires) ignition coil. The ONLY difference between the Red/Yellow and Red/White ignition coils--aside from the color of the wires--is the MAGNETIC polarity. The output power, resistance and ELECTRICAL polarity is identical.

[Steptoe]

The spark is made up of voltage and current..
We could have high current and low volts, but that sort of causes electrocution and deaths if get zapped
So cars have high volts and current....end of the day it is the energy that is drawn that gives the spark its intensity.
And the more voltage u throw at it the less current, but the energy dawn is determined by the total circuit resistance... just like a light build.
So we may throw reduculous amounts of voltage at a circuit, above what is required, but the effect doesnt change unless that circuit has changed.. ie bigger gaps, be they in the cap rotor to pins or the spark plug gap... and mixtures also effect resistace across the plug electrodes, espec if lean.
For street / mild track stock voltages and current draws are far more sufficient, and the modules far more reliable since the 1st production ones 40 yrs ago.. as are modern after market leads.

If u whack up into very high voltages then u also proportionally run into issue like arching , blowing holes in the sides of wires... exactly the same as id whack up the pressure(voltage) in a water hose.. and leaks thru any joins.
Which is why running high 'track' voltages on the street become unreliable long term.

[kikkegek]

thanks Steptoe. makes sense. like always when you reply.

I checked out your link to the Top Gun leads. They say LPG takes about 20-30% more to ignite and therefor they have lowered their basic leads from 5-10kOhm/ft to about 2 kOhm/ft. Their MAX300 leads are 300 ohm/ft.

that answers my question. 40-50 Ohm leads will put too much strain on my system I guess. So in time I'll change my 5kOhm leads to a pair of MSD Streetfire leads that have about 500 Ohm/ft and are very affordable.

[Steptoe]

I did not know about that and the top gun.....
Mind you these set of spiral wound leads in the camaro, and vintage cars, has to be at least 10 to 12 yrs old now...
One thing that I find with these top gun is how they can stand up to stuff like touching cast iron rams horns exhaust manifolds....for long periods I suspect .. because often the hood doesnt get lifted except if pre going on a road trip or oil change/ services....
I NEVER pull on a lead so cant comment at all about how robust they are in that respect....
OH and as to blowing holes, leaking.. never had an issue.