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Hot Rods ignition points help !

Discussion in 'The Hokey Ass Message Board' started by larry k, Dec 12, 2016.

  1. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    points help !!!!!! On a Chevy points type distributor ,Can I run the wire from starter R post to the resistor post that feeds the coil, or does it have to go to the coil ???
     
  2. squirrel
    Joined: Sep 23, 2004
    Posts: 56,085

    squirrel
    Member

    you can connect it at the resistor, just make sure it's connected on the coil side of the resistor.
     
  3. henry's57bbwagon
    Joined: Sep 12, 2008
    Posts: 680

    henry's57bbwagon
    Member

    I seem to remember a wire from the R post from starter goes directly to the + side of the coil and is 12 Volts at start only. From the Key it goes to a ballast resistor and is about 8 Volts for running.
     
    Johnny Gee likes this.
  4. squirrel
    Joined: Sep 23, 2004
    Posts: 56,085

    squirrel
    Member

    the original yellow wire on those 1960s Chevys connected directly to the coil...but it had to, because they didn't use a normal ballast resistor, they used a resistor wire (it is cloth covered, kind of easy to spot). If you have a normal ballast resistor, then it does not matter which end of the resistor-to-coil wire you connect the bypass wire to.
     

  5. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    The problem I have is all the wiring seems to be ok ,new rebel wiring, new condenser, new rebuilt distributor,new points,new 1.5 ohm coil,new1.4 ohm resistor,that makes it a 2.9 ohm system.so point heat should not be a problem at the points, ,,,,,right ? But my points only last about 3000 miles then I get a miss and shutter on hard acceleration ! File "em" or replace "em" reset "em" and the miss is gone for about 3000 miles .
     
  6. Chevy Gasser
    Joined: Jan 23, 2007
    Posts: 718

    Chevy Gasser
    Member

    GMC Bubba here on the H.A.M.B. is a distributor expert, He also knows Pertronix. Another distributor expert is Bob Soucy, (239) 671-3974. If anyone has an old Mallory dual point that you would like to use but cant find points for, Bob can convert those to Pertronix for as good as Mallory or better performance.
     
  7. squirrel
    Joined: Sep 23, 2004
    Posts: 56,085

    squirrel
    Member

    Did you make sure you have the right condenser (matches the coil)?
    and it's in good condition? They don't make them like they used to...
     
    henryj1951 likes this.
  8. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    I bought the only condensers that they had at NAPA for a Chevy 350 with points .don't know any numbers on the microfarads for them . I am installing a new set of unipoints today! Heard good & bad info on them. Got to be an answer somewhere. Cars ran 15000 to 20000 miles on set years ago !!! Member them days ???
     
  9. henryj1951
    Joined: Sep 23, 2012
    Posts: 2,306

    henryj1951
    Member
    from USA

    them days -- we could buy plugs, wires, cap, rotor, points, and cond
    way under 10bucks, excluding the cost of wires.
    the idea of a major tune up was all the above, the idea of a once over,
    maybe just before a vacation or just before winter(those living in the cold zone)
    would be points , cond, and plugs, check and set carb-n- timing.
    i think i have an old 3x5 card i used to pass out that said tuneups 10.00,
    and it said you get plugs cap rotor points, and cond,
    and (no plug wires )that wasn't all than long ago 1969 1971 as i recall.
    and keeping some of the street rods , at max tune ,one would check set, and or replace points (2) twice
    a year.
     
    Last edited: Dec 12, 2016
  10.  
  11. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    Well , while I take the "OL elcamino" for a test run , I'm just waitin for GMC bubba to give me his take on this problem .tween Him & squirrel they have to have the most respected advice on the HAMB !!!
     
  12. saltflats
    Joined: Aug 14, 2007
    Posts: 12,602

    saltflats
    Member
    from Missouri

    If you put the uni points in put the condenser hold down back in the dist so if you go back to the separate points and condenser you will have the screw and clamp waiting for you.
     
    squirrel likes this.
  13. henryj1951
    Joined: Sep 23, 2012
    Posts: 2,306

    henryj1951
    Member
    from USA

    check the old points to see which way the build up pattern is going.
     
  14. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    Not much build up positive or negative , Just maybe a shade to the positive side.just nice and gray, pretty flat and used ,they should be fine to run ,, and there you see my problem.
     
  15. henryj1951
    Joined: Sep 23, 2012
    Posts: 2,306

    henryj1951
    Member
    from USA

    A condenser with to much capacitance will cause a build up (metal transfer) on the mounting side of the points.
    a condenser with not enough capacitance will cause a build up (metal transfer) on the arm side of the points.
     
  16. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    I really have hard time finding a parts guy that knows what a ignition condenser is , let alone what capacitance is , or how to measure it in microfarads , guess I will make a call to bubba Linder in Indy .
     
  17. henryj1951
    Joined: Sep 23, 2012
    Posts: 2,306

    henryj1951
    Member
    from USA

    from the net---> long but good read----
    For the record, "condenser" is an age old term, and "capacitor" is a newer term for the same device. Automotive ignition capacitors are still commonly called condensers.

    Many people will replace a condenser with regular periodic maintenance, just because they have no way to tell how much longer it might last. But some new condensers might be bad right out of the box, or might fail very shortly after installation. My approach is to carry a known good condenser in the traveling tool kit, and don't replace the old one until it fails. For this to work you have to be prepared to change one at some inconvenient time, possibly on the side of the road, but you should be prepared for such a possibility at all times regardless.

    For decades I have had very good luck with condensers, but in recent years there have been lots of reports of condensers that fail prematurely. In December 2013 I had one fail after 18 months and 9000 miles. The two months later another one failed after only 257 miles. Even regular replacement at reasonable intervals could not avoid these premature failures. This begs the question, how do you test a condenser to determine if it is good or bad? Well, even when you can test a condenser, this is still not the final solution, as a condenser might test good one day and fail the next day. But periodic testing of the condenser in the car might (sometimes) disclose a deteriorating condition before it actually fails. Testing can also verify a suspect condenser that might fail soon after installation. If testing reveals an apparently good condenser, then you can look elsewhere for a problem without having to replace the part.

    For anywhere from $20 to $200 you could buy a condenser tester. The real tester can apply a high voltage (500 to 600 volts) to test for leakage, and can also apply an AC current to actually measure the capacitance (storage capacity) of the device. These two tests more closely stress the capacitor in the same way actual operation does. But considering that a condenser is a cheap part, and you should always carry a known good spare anyway, the condenser tester seems a bit overboard for the average shade tree mechanic. Fortunately there is a way to do a rudimentary test with a common analog (moving needle) ohm meter.

    1.) Remove the condenser from the engine (or at least disconnect the lead wire). Note the small metal connector located on the end of the condenser. This connector is the "hot" or power connection. The metal case of the condenser is the grounding point. Discharge the condenser by shorting the lead wire to the case.

    2.) Switch the meter to the ohms position. Place the red lead into the "ohm" connector on the meter. Insert the black lead into the "com" or common connector on the meter. Set the resistance range to the highest available setting (if it is selectable). Connect the test leads together and zero the meter. If the meter won't zero replace the battery. (Yes, an ohm meter has a battery).

    3.) Touch the red lead to the hot connector on the condenser. Place the black lead to the metal case on the condenser. The meter's needle should jump slightly to the right (toward 0-ohms), then should drop back to the left towards infinite resistance). Hold the leads in place for 15 to 20 seconds. This action places charge in the condenser. If the test shows any reading other than infinity, the condenser is leaking and needs to be replaced.

    4.) Remove the leads and reverse the placement to the condenser. Move the red lead from the hot connector to the metal case, and move the black lead from the metal case to the hot connector. At the moment where both leads are touching the correct points, the meter should jump towards the right. The second time the needle may move twice as far, as this action discharges the condenser. Holding the leads in contact should again result in movement of the needle back toward infinite resistance.

    5.) Movement of the meter's needle indicates the condenser is good. If no movement was indicated on the meter in any circumstance, the condenser is bad and must be replaced. Retest the condenser several times for a consistent reading.

    In operation the condenser will "ring" at up to 300 volts, so the condenser needs to be rated much higher, no less than 600 volts DC. The ignition will likely work with any capacitance value between 0.05 and 0.6 microfarad. Too high or too low value may eventually transfer metal from one side of the contact points to the other side leaving a pit and a point. Capacity of spark coil capacitors ranges from 0.2 microfarad to 0.33 microfarad. Almost all automotive coils use a 0.25-0.29 microfarad capacitor.

    A capacitor may absorb moisture over a long period of time, and moisture can cause failure of the condenser. So it is possible that a condenser stored for 10 years or so might be bad or might fail prematurely in service. It is a good idea to check your traveling spare condenser occasionally.
     
  18. larry k
    Joined: Feb 23, 2009
    Posts: 548

    larry k
    Member

    Thanks Henry , that's cool info to have I will test my old condenser and see if it falls between 0.25 and 0.29 that may be my problem right there ?
     
    henryj1951 likes this.
  19. jimcolwell
    Joined: Oct 4, 2009
    Posts: 474

    jimcolwell
    Member
    from Amarillo

    Always change the condenser when you mess with the distributor.
     
  20. Remember buba is on vacation till first of the year.
     

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