So Ive been fighting typical flathead sputter, stammer,*****ty running for a week now. 8ba, 2 94's, 12v, stock dizzy. Normal stuff, sluggish under load, backfiring under load, idles good starts good. My first suspect was condensor, changed it still bad. Second, plugs, went to NGK, runs better, but still bad. So today Im thinking coil after reading all Bruce Lancaster posts. I pop my hood after driving about 20 minutes, and tougch the coil to see if its hot (ive been told when coils burn out, they are extremely hot to the touch, like unbearable) not hot. Then I get to thinking, its not hot at ALL, like luke warm at best. Common sense tells me its opposite of burning hot, so maybe its mot getting enough juice? Now im running a ballast mounted to my inner fender. I think for*****s and grins, lets try running it w/o the ballst VIOLA! runs way better, not perfect, but doesnt sputter, no backfire, about normal. So my questions are: 1 do I have to run the ballast 2 can ballast cause this issue 3 should I get a new/hotter coil anyway Thanks in advance and thanks to the HAMB already for helping me get this far!
There are a lot of unknowns here that prevent direct answers. Do you know the ohm value for the ballast resistor?? How is it wired; if the resistor is wired using the stock harness you could have series resistances. Take a DVOM and measure the voltage at the B+ on the coil with the resistor in place, then measure at the ballast where the harness attaches; if you are running 12 volts you should have near that at the ballast. The difference between the coil voltage and the ballast input is the voltage drop through the resistor...How hot does the resistor get when it is running? ...gone for the weekend but others will jump in to help.....fats BTW: The part # on Standard Ignition ballasts indicates the ohm value: RU-10 is 1 ohm...Ru-12 ==1.2 ohm etc.
If it's an internally ballasted coil and you're running an external one as well, that would explain running better when removing the external one. 8BA dissies are not known for performing well with 2 94s. Swap 'em out for 97s should give you a better running engine.
1. Some 12volt coils have an internal ballast and do not require another. Most are marked as such. The ballast resistor lowers voltage after the engine is started to reduce wear on ignition components. It also makes the engine much easier to start by effectively doubling the voltage provided to the ignition coil when the engine is being cranked. 2. Oh yea. 3. I would take that distributor and give it the naval flotation test. (as Bruce says) The 8ba dizzy is ineffective and does not normally provide the correct advance. Buy a GM distributor from GMC Bubba who makes an adaptation for flatheads. 4. 8ba dizzy are made specifically for 94s because only those carbs provide a a vacuum port below the venturi. 97's dont have them. Dont be confused with inaccurate information. This engine has been running 94's with the original distributor for 5 years. But that is not the norm. Most of the time they dont run well when running two carbs. Two carbs cut the vaccum suction to the advance on an original distributor. pj
What about the points? Did you MEASURE the dwell? Everytime I have those symptoms it's either the point gap or worn contacts on the points causing it.
On the coil, you must find out what it was made for and whether it takes an external resistor...though your experiment gives a pretty good clue! Either get an OEM replacement coil together with resistor as specified, or if a speed equipment coils find out what the catalog says. Remember that if coil is actually meant for a specific resistor valur but the coil is on its way out, removing the R will boost primar voltage and crutch up a dying coil for a while. I'd want a spare at this point, and get either a junkyard coil and R for like a 60's Ford or Echlin replacements for the same... A good distributor will be an excellent improvement...it is likely you are running too retarded much of the time with the Holley distrib, and that itself causes all sorts og negative symptoms...
I got an electronic distributer from GMC Bubba in my Shoebox. It made a world of difference, the car runs great.
GMC Bubba is going to be my next call. Ive heard nothing but great things about him and everyone ive seen with his dizzy runs incredibly well. Right now i have no advance at all. I know, that*****s, but its life. Ive been driving the car for 6 months like this with no problem, then it starts acting up this week. I hate to play broke guy, but that 140 for the dizzy takes me a few weeks fo come up with, and the shoebox is my only car, truly a daily driver, I have no other cars. So I needed a quick fix that good enough. I will check the part number on the coil though. I was looking at the Echlin ones at Napa earlier, Im going to go to one of those, but same story, 40 bucks can keep the lights on at my house, haha. So can I keep running the system like I am now: no ballast?
I will ship a new one to you for now. You can pay me when you get the money. Hows 100 bucks sound? I would buy a new internally resisted coil and be done with it. Yours may not be internally resisted and if you read what I wrote above that will burn your points. pm me on the dizzy PJ
Pete yuore PMed and Im going to have to find out about the coil. I believe I got a coil for a 60's Mustang, but I dont recall if it was internally resisted.
Question: How do you know it is spark in the first place? You could just as easily have a fuel issue -- hopefully you've done your homework before you start replacing parts. The fact that you've been driving it for 6 months before the problem tells me that the coil and resister were probably fine (made for each other). You need to check the points, dwell, etc -- cheap and easy to figure out if you have an issue. On the coil, just go pick one up at Napa, AutoZone, etc . . . should be an easy thing to do and relatively cheap. Or go to the junkyard and get something for cheap and validate whether it is your issue in the first place. Don't run it with direct 12Volts if the coil is made for an external resister - you'll be burning the points in a short period of time. Check ALL your wires and contacts -- points, plug wires, etc.. Use a DVM to validate what voltage you have to the resister, coil, etc.. Also - cap and rotor . . . you could have a cross-fire issue . . . my guess is not, but also something to think about. Again - this car ran decent for 6 months . . . something has started to fail. Fuel, spark . . . something.
So just to lay it all to rest, it was the resistor. It got paint on it somehow... (sitting on a shelf next to things I was painting) and I guess that was that. An old times at NAPA said it probably didn't allow it to "breath enough" and that can cause it to fail? Either way, new resistor and shes running as good as a flathead with no advance can, haha.
I had a problem like that on my 8ba once. I am running 2 94's with a stock dizzy. An oldtimer told me that the dizzy vacume source had to be plummed from the back of one of the 94's, not from the manifold. The correct vacume for advancing the dizzy was on the back of a 94 in the middle of the vinturies on a threaded port right under the 94 logo. After I swapped the vacume source my motor advanced and ran great. This may not be your problems solution but its something to check and its free to fix.
An original 8Ba dizzy will work backwards if it gets manifold vacum. It must use the Holley carb venturi vacum source. By the the way without vacum no advance at all. http://www.btc-bci.com/~billben/navarro.htm
The Jalopy Journal
