This questions concerns a carb 308. I have searched here and there certainly are a lot of posts about it. There are brand recommendations. Extenders mentioned. The points versus electronic posts. Hotter plugs versus colder ones. Etc. My question: is there a minimum resistance per foot requirement on these older cars? My problem is I seem to have run into a fouling problem with recent work done on the ignition system. The most obvious change is my new wires are radio supression and thus 10X plus the resistance of the old ones. In another thread here it was suggested longest wire resistance should be <1000 ohms. But, we are talking about high voltage low current, right? Can I not run radio supression wires? I probably have much to learn... . My plugs are NGK BP7ES which were running fine with the old wires (that I still have). Seamus
I ran stock wires (new) with NGK BPR6ES plugs the "R" standing for "resistor". It solved by radio interference problem with my Family Service Radio I used on FCA drives. In other words I took care of the RFI issues with the plugs, not the wires. BTW, even though you may have got away with an NGK "7" plug, most everyone uses a "6"....and some even use a hotter still, "5". What is your jetting like (stock?) and what year is your car?
It's a 78. Don't know the jetting. I know I should and I have been "right there". But, I am trying to finish one job before starting another. So, I haven't messed with that part of the car. It ran good before this work. And this work meant new ignition pieces. Pretty certain my troubles are from the distributor cap to the plugs. My chief suspects at this point are the wires (RFI & high resistance), plugs (gapped too small in comparison to the ones I took out), and plugs (7 vs 6 -- based on reading posts here).
Are you running points? If so, then stick close to the stock (smaller) gap. You can run larger gap if you are using upgraded coils and electronic ignition (Crane, MSD, etc).
NGK BPR7EIX that is the newer style Iridium plug, which supercedes the previous platinum version. Not a huge deal, I would imagine your car would run fine with the oem type BPR7ES, but the Iridiums are claimed to last much longer.
Don't get hung up on the Ohms per foot figures. It is mostly a sales gimmick. Spend some time reading the articles here: http://www.magnecor.com/magnecor1/main.htm
IIRC, the stock 308 spark plug wire is about 700~800 ohms per foot (as measured with a low voltage ohmmeter) so they'd vary from about ~700 ohms for the shortest to maybe ~2K ohms for the longest. So including ~2K ohms (?) for the extender (and 0 ohms for a non-resistor plug) you'd be in the 2.5K~4K ohms total for the stock situation. But one thing I'd note is that the piercing screw for the connection at the dist cap isn't really designed for connecting to the conductive ribbon type wire. Usually the end fittings for those wires are designed to have a couple of broad contact areas with the conductive ribbon -- not a single, localized small piercing. Did you expose and fold over some of the ribbon at the end so you pierced it twice? If you keep fouling plugs, you might also try the IX or VX NGK plug style that Dave H. mentioned -- my ex-308 would foul the standard ES electrode NGK plugs in just a few hundred miles, but the V/VX NGK plugs extended that out to many thousand miles -- just a suggestion...
A few years back I redid my wires on the 77. Just went to the local auto store and bought some carbon core resistor wire by the foot and cut it to length and assembled one end and reinstalled. I have the black extenders and use NGK BP5ES plugs gapped at .030". I have a Pertronix's breakerless ign.with the timing set at 7*BTDC at 1000RPMs. I have no RFI problems on my radio and the car runs great. I have it tuned a little rich. I found that if I ran the 7ES plugs some of them would foul so I went with 6ES and then to 5's. Works for me. Buy the way I did this in 2000 so I have 7 years on the plugs and wires.
My 6's just showed up tonight. Will try them this weekend. Based on all the different numbers I hear still not sure where to gap. Thinking your 0.30" probably good as I still run points. Also not sure about the wires. Is all the talk about low resistance just a myth? Even for points cars?
As much as I would like to believe them, what they tell about Nology is so far away from truth and from any basic knowledge about capacitors, that it makes their theories in general quite questionable. That's a shame. In general, a cable may be up to 5Kohm, more is not to be prefered
Nology capacitor wires are garbage. The saying comes to mind, "A fool and his money are soon parted".
That can very well be the case, I do not defend Nology, but Magnecor should use real arguments, and not show us their ignorence on the subject and tell us nonsense.
Drilled out the expansion tank overflow tube. Set coolant level mid-way. Solved the coolant bubbling onto exhaust problem, or bubbling out at all it appears. Switched to BP6ES gapped 0.30". Set timing. Ran 30 or 40 miles in light rain with the high resistance wires on a variety of roads. I would say running the best yet . Can really rev it up going through the gears. Idles good. But... when I checked timing at idle after setting on the mark at 5000 it's not even close to the AF7 . I'm wore out working on this thing. The thought of yanking those distributors off again to clean up and lube the spring advance mechanism? Ugh. Seamus
