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So How Do I Adjust The Points?

Discussion in 'Technical Q&A' started by donaldh2o, Jan 26, 2004.

  1. donaldh2o

    donaldh2o Karting

    Nov 10, 2003
    143
    Irvine CA
    Full Name:
    Don
    To adjust the points on a '76 308, the shop manual says:

    Make sure that the opening angle of R1 breaker points is 56 deg. + or - 3, and the closing angle is 34 deg. + or - 3.

    What does that mean?

    Can I just simply print a compass diagram onto a piece of paper, like the one attached here: cut it out like a donut, glue it to face of the distributor, making sure that zero is on the TDC mark, and adjust the points to close at 34' and open at 56'?

    I did just that and there's no way to adjust the points to open and close at those points along the compass. The closest I got was close = 48 degrees and open = 84 degrees.

    Or is it possible that I'm not even close with this technique and the text in the manual refers to something else entirely?

    Or could it be that I've got single-point distributors and the adjustments are different than shown in the manual which refers to dual-point distributors.

    I installed new points. Could my distribitor shaft be worn?

    Something's wrong. ???
     
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  3. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,485
    Texas
    Full Name:
    Steve Magnusson
    The 34 deg and 56 deg numbers aren't (distributor) degree positions, they're (distributor) degree durations -- 34 degs closed, followed by 56 degrees open, followed by 34 deg closed, etc.. 4 cycles of 34 deg closed + 56 deg open is 360 deg (4 lobes on the dist cam).

    If you want to use distributor degree positions they would be (arbitrarily starting with the closed cycle):

    0 deg start -- points close
    34 deg -- points open
    90 deg -- points close
    124 deg -- points open
    180 deg -- points close
    214 deg -- points open
    270 deg -- points close
    304 deg -- points open
    360 deg (= 0 deg) -- points close
     
  4. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,337
    San Carlos, CA
    Full Name:
    Mitchell Le
    I found that I have to remove the distributors to even get a chance to set the points correctly, else my neck would hurt too much from being inside the wheel well.

    Or you could replace the whole thiing with Crane system, and forget the points and condensors forever. Which is what I did, and thank god I am not going back.
     
  5. Jay GT4

    Jay GT4 F1 Rookie

    Oct 16, 2001
    4,995
    La mamma dei fessi
    Full Name:
    e sempre incinta
    How do you adjust the points? Easy...you put in 2 electronic ignition boxes and hide them in the trunk or over a frame rail, then you will never have to worry about setting points again.
     
  6. donaldh2o

    donaldh2o Karting

    Nov 10, 2003
    143
    Irvine CA
    Full Name:
    Don
    Steve,

    Thanks for clarifying that!

    I've printed your reply and am forthwith on my way to the garage to resume setting the points.

    The total paragraph in the shop manual says:

    Rotate slowly (operating direction) the tester motor equipped with scaled disc and stroboscopic device. Make sure that the opening angle of R1 breaker points is 56' and the closing angle is 34'.

    Well I don't have that gizmo. I'm using the paper donut glued onto the distributor (scaled disc) with a chirping ohmmeter (stroboscopic device).

    BTW - Nice looking TR!
     
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  8. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,485
    Texas
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    Steve Magnusson
    Don -- thanks for the kind words -- you need to put a jpeg of your 308 in your Profile too!

    That passage you quote is typical of many F technical translations IME -- it doesn't say anything wrong, and it gives the right numbers, but it doesn't give an easily understandable explanation (unless you already know what they're trying to say).
     
  9. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    573
    NW Rural Nevada
    Full Name:
    Mike Florio
    You will notice that the points plate has elongated holes for the mounting screws. The whole plate can essentially rotate a few degrees inside the distributor. This adjustment is to align the points with the cap/rotor.

    There is a notch in the rim of the distributor housing that corresponds to the location of the #1 cylinder pickup on the cap. I'm not talking about the pin, which locates the cap, but a little notch in the top rim. The rotor should be centered on this notch when the points open.

    You can tape a little wire pointer on the rotor extending over the rim, and then rotate the shaft by hand and check with your chirping ohmmeter to make sure the points open exactly when the wire is pointed to the notch. I think a simple test light works better. Rotate the points plate to adjust. Then check the dwell again. When you change the dwell it will change the point where the spark is delivered to the rotor, so you may have to do it a couple of times..
     
  10. Peter

    Peter F1 Veteran
    Rossa Subscribed Owner

    Dec 21, 2000
    6,389
    B.C., Canada
    #8 Peter, Jan 26, 2004
    Last edited by a moderator: Sep 7, 2017
    Image Unavailable, Please Login
     
  11. robertgarven

    robertgarven F1 Veteran
    Rossa Subscribed Owner

    Feb 24, 2002
    5,085
    Ventura, California
    Full Name:
    Robert Garven
    It has been a couple of years since i did it, and Steve talked me through it back then, but I just used a feeler gauge to set the points with the units off the car and they have run spectacularly since. I now have a machine like Mike but I am still trying to figure out how to fix my antenna and pushing in my bumpers before i get to that project. Oh yeah I need to rebuild my cars too! :)
     
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  13. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,359
    NY
    I would use the take the dist. out on the bench and set it with a feeler gage (gap .012-.015"). Check it 3 or 4 times just to make sure. Also rotate the shaft just to make sure. Put the units back in and then check them with a dwell meter (R2 dwell is 34Deg +/- 3 Deg).Need to practice to get this but once you get the trick it works. Then go get a breakerless setup. I got Pertronix's in mine.
     
  14. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    573
    NW Rural Nevada
    Full Name:
    Mike Florio
    Steve:

    Sorry to respectfully disagree, but R2 Dwell is 39 degrees, R1 is 34 degrees. If you use both sets of points, which is probably necessary to pass smog, the R2 points open 5 degrees BEFORE the R1 points, thus retarding the spark 5 degrees (when the throttle linkage microswitch is closed). Both sets of points should close at the same time. This relationship is difficult to obtain on the bench, but can be done with a degree wheel and a test light. In my experience, a feeler gauge will get you close, but a dwell meter is really necessary to be spot on.
     
  15. robertgarven

    robertgarven F1 Veteran
    Rossa Subscribed Owner

    Feb 24, 2002
    5,085
    Ventura, California
    Full Name:
    Robert Garven
    Steve, Mike et al,

    I assume we all have only the R1 points set up???? My car passed CA smog 3 times with only the R1 and a tubi (with both functioning smog pumps)Mike and Steve M. know more than I do about this but the feeler gauge set-up can be done. I would not switch out the points as it seems wrong on a classic car. Mike, I am almost there (working on the allen)!
     
  16. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    573
    NW Rural Nevada
    Full Name:
    Mike Florio
    Robert:

    Wait until you get your Allen running. Its a dream to set up the distributors. You can even set the dwell adjustment with the distributor running. Just hook up a dwell meter and adjust on the fly.

    I messed around with my advance mechanisms and got them to match in both distributors (they were a bit off). My Jet Engine Mechanic son is driving up tonight and we will install them and have a road test tomorrow.
     
  17. 4Webers

    4Webers Formula Junior

    Nov 12, 2003
    276
    Texas
    Full Name:
    Darrell
    Mike,
    Thanks again for all of your help on the Marelli adapter. I'll be bugging you again when it's time to get both dizzy's advance curves to match. Some day I'll know something useful and return the favor.
     

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