Hi all.... just looking for opinions here on an issue that I seem to be having. Little background, I just got the truck on the road a few weeks back and have been dialing in the ignition a little bit at the time. The engine is a 327 with 461 heads, forged pop-up TRW pistons 11:1, from the numbers the cam is a '70 LTI with solid lifters, old Cloyes double roller chain timing set, Eddy RPM Airgap intake and 670 Holley. Fenderwell headers. The ignition is the original single points, undetermined mech weights and springs (yet to be addressed). I just put in a B28 vacuum can to bring up my advance at idle (using a TH350 w/2400 stall) as the truck would sometimes stall in gear. I have an Accel Superstock coil and matched it with a generic (of the proper ohms) ballast. Problem I'm currently seeing is the points seem to burn in this thing. I'm having to run a fine line of advance (about 17-18 deg initial) to have the engine run strong, but not ping. I have to bring the mechanical back in like i said as it is around 42 deg. right now, but looks to be all in by 2500. Dwell is at 31 deg. The engine was built back in the '70s and with the exception of me breaking it down last winter for inspection and re-gasket,is the same motor from back then (it only had about 2500 miles on it when removed). This points burning has me scratching my head...any opinions on what maybe to look for? Thanks much, Tom
Just thought, do you have a starter sustain wire to the coil and is that going to the input side of the ballast. I have seen them by pass the ballast sometimes.
I have the ignition wire from the "Ignition/run" position on ignition switch go to the ballast, then from the ballast to the + side of coil in the "run" position. I then have a separate wire on the "Acccessory" side of the ign switch to a starter button to neutral lockout then to the starter. from the switched side of the starter I have a one-way wire with a diode to the + side of the coil. I have not tested the voltage on the coil wire to the distributor, but I'm guessing it should be 8-9 volts if all is good (done while engine is running)...I know when the engine is stopped and the points closed the voltage is 12+.... Can a ballast be bad and give full voltage across it? I think i have everything hooked up right, unless I'm missing something? Tom
Hmmm...I have 12volts going to it on one end and 12 volts coming off the other end. Just 1 power wire on one side, then out to the coil. nothing to back-feed.....just curious, that this does not sound right now that Im thinking as there was no drop in voltage from one end of the ballast to the other???
Do the voltage readings with the engine running. If the points are open (no current flow) you will see 12v at the coil A bad condensor will cause points burning as well as a bypassed ballast. Old Henry on the Fordbarn has this test method. It works. The condenser can be checked with a multi-meter by either checking the microfarad reading (the better way) which should be at least 24 mfd (most of the stock style made in Argentina), better over 34 (Echlin from NAPA), or, if you don't have a multimeter that tests microfarads you can get a pretty good idea if the condenser is working by using the ohms function of the meter. Connecting the two probes of the meter to the condenser wire and case should show ohms climbing rapidly from 0 to infinity. If you get a good reading on either of those tests the condenser is OK. The values should be in the ballpark for a single point set although they are for early Ford. Also make sure there is a good ground of the distributer point plate to the block block.
Here is a simple wiring diagram for the ignition. The only thing that I don't like is that the wire they show going from the switch bypassing the resistor should be going from the "R" post on the starter solenoid or possibly run through a push button on the dash so it is out of the system when the engine is running. I went back and read post five and see that you are running your wire to the "start" pushbutton off the ACC side of the ign switch. Odd, but it does kill the power to the push button when you have the key off. I'll have to read your post # 5 again when I get home from work as I think you created your own problems with the way you have it wired but I'll have to draw what you wrote on paper to under stand what you did.
Yes, resistor needs to warm to its job. While messing around, check out the other side of circuit...ground wire from point plate intact and firmly screwed down, the ground the case...ground wire from distributor, likely using a vac can screw, to a solid chassis ground. High resistance on ground side messes with in side...
The only thing in my description now that I think of it that I described wrong was I am running the wire to the coil from the "run position" on the key switch (this is the only wire out on the key in the run position)... and on the "access" side I have the wire running to the "start" button, then to the starter (through the lockout). Then from the switched side of the starter direct to coil (where I have my diode wire, starter is a mini starter so it only has a battery, the switched side and the switch connection). I'm pretty sure that is all hooked up correct, but who knows.... no radios or accessories.... Had my original description back asswards... I'm thinking I need to do a voltage check on the positive side of the coil with the engine running to see where that is actually at.
I'm beginning to think that the voltage from the + side of the coil to ground needs to be checked with the engine running also... the points opening/closing should bring the voltage down, correct....I know for a fact I can get 12 V from one side of the ballast to the other... possibly with points open?
I replaced the vac can, and so I know I have the ground wire attached.The only ground i have from the distributor is it's connection through the engine. I have the engine grounded to the chassis is (2) spots both with #2 wire, (1) near the starter and one from the front of the block...never have too much grounding. IMO.
Rule # 37: Anything EVIL and PUZZLING will turn out to be a ground problem, usually after you replace most of the car without helping anything...
You need to check the ohms of the Accell coil. If it has lower ohms than the stock coil it will take more amps. And the amps go thru the points. More amps=faster fyring. Also the new cheap points from a parts store ain't gonna work. You really need Delco's or old stock points.
Little more information.... The coil is a 1.4 ohm coil the ballast is rated at 1.6 ohms... the burned points were a set of 25 year old ones I had (but were initally pretty good), and the new point set I installed were a set of Wells points and cap that were new from 20 years back I had bought for an old project car (I installed these last night and are my last set). Coil and ballast are also new...I do not have any old delco coils but probably have a Ford coil or two..
You should be getting less than 12 volts when the ballast resistor has warmed up. This can be the reason for the burned points. What does Accel sugest for the B.R. Ron
Yes with power on and the points open you will see 12v on both sides of the resistor and both sides of the coil primary. If you do catch it with the points closed take your measurments quickly as you could burn out the coil or resistor. You want about 6 volts at the + side of the coil.
It was my understanding to just shoot for the "like" values on each, at least that was what I was always told.
That's a problem ^ You should have 12 in and 9 out in run position. The "I" terminal off the starter should go directly to the positive side of coil. It will have 12 volts in start to coil. That same wire will show 9 volts in run but go no where. I dint read past this post so its probably been addressed
The resistor doesn't have to get hot to lower the output voltage. The resistance that lowers the output voltage causes the resistor to get hot. If it doesn't get hot it isn't working. With the key on you should have 12 V on the switch side of the resistor and around 9 V on the coil side. The only time you should have 12 V on the coil side is when you are cranking the engine with the starter and you are getting 12 V to the coil through the resistor bypass wire from the solenoid.
You should have less that 12 volts at the coil when the points are closed, and the balance of the voltage will be dropped across the ballast. So if your battery voltage is 12.6, and you measure 7 volts at the coil, you will have a voltage drop across the ballast of 5.6 volts, measured from one terminal of the ballast to the other. If you don't, either your ballast is shorted or your points are not conducting. Warm or cold, there will be less than 12 volts on the coil side of the ballast when the points are closed.
Yup as I noted, new condensor, new points, new cap, new rotor, coil, ballast (other than the coil and ballast all the parts are old american made parts)..... I did just check the running voltage on the coil and it is right at 10 volts... maybe a volt too high, but the ballast looks to be doing its job...possibly a different ohm ballast would get me a volt lower, but the 10 volts might be a little high......I run about 9.8 on my OT car with dual points, and never had an issue...but a differnt situation ui know.. Tom
The system should use approx 1.5 ballast and approx 1.5 ohm coil. Both will vary when hot and flowing current. Also the primary wire to the points to the neg side of coil should be a final resistor and a factory lead wire , available from napa or let me know and i can get you one. Contacts and condensor MUST be quality parts ( echlin heavy duty) and condensor should be the correct rating in mfds, ( many are not). Now lets talk about the circuit, you should volt drop the parts when loaded (points closed) or better yet running. If we do it with points closed we need to place a volt meter across the ballast ( neg to pos) and on a 12 volt system it will read 5-6 volts. The the same test on the coil and it should read 5-6 volts as well. This is the voltage being dropped ( or used) by the component. SO a resistor dropping 5 volts ( 12 volt battery) and a coil dropping 5 volts would have a "correct" volt drop of 10 volts . This would leave approx 2 volts and that 2 volts is dropped by the factory finely stranded primary lead leaving 0 ( actually a few .10s) across the contacts . WALA a perfect system !!! If you are eating or burning points then one of the above is incorrect!!!!! Now do the same thing with the engine running at 14.6 or so volts. Get a calcuator out and give us some numbers , the system must use (or drop) all the voltage ( electrical pressure) Get us some numbers and post them for us all...... Just a note : I got a box of standard motor products ballast resistors in today . Sec is 1.5 ohms and all 12 checked .5 ohms !!!!! Its a buyer beware world!!!
While a bad condenser CAN be the reason for burned points, it is not the primary suspect in this scenario. The ballast resistor appears to be less of a resistor than it should be in this case. As GMC Bubba pointed out, measure the resistance of the ballast, it may be much lower than advertised. One thing to consider when measuring the "running" voltage at the coil is that voltage will be a weighted average of the "points open" and "points closed" voltage, based on the points dwell angle, so will be different than any measurements taken when the engine is not running. I apologize in advance, there may be some youngsters on here that have never used a dwell meter to set points.
The Jalopy Journal
