Distributor issues

Discussion in 'Small Block Tech' started by wolffang92, Oct 7, 2017.

  1. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    If your exhaust was quieter, I might be able to tell. Get the part number off the distributor you bought. Should be 7 digits, right on the circumference of the distributor, just below where the cap goes on.
     
  2. wolffang92

    wolffang92 Well-Known Member

    Right on. I'll check it when I get home.
     
  3. wolffang92

    wolffang92 Well-Known Member

    The numbers stamped on it are 1111938 8k12
     
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    1969 Buick 350-2, See below,

    1969DistSpecs.jpg

    30-34* of maximum mechanical advance at 4600 RPM. This distributor was supposed to be timed initially at 0* (TDC). If you are running more initial, that is why it is pinging.
     
    wolffang92 likes this.
  5. wolffang92

    wolffang92 Well-Known Member

    Well, I fiddled with it quite a bit today. Can't seem to figure out why it's pinging. Adjusting timing from 10 to 0 where it's supposed to be at didn't seem to affect it at all. The only thing that does seem to affect it is messing with the dwell. It seems the lower I set the dwell, the less it pings. If I have it set at 30 it pings really bad.
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Dwell changes timing. Set it to 30*, Then set the timing.
     
  7. wolffang92

    wolffang92 Well-Known Member

    Oh, yeah. I reset the timing after I messed with the dwell. Didn't seem to help. Before I hooked up my timing gun and dwell meter I was at roughly 20* dwell and 12* BTDC. That setup gave me less pinging than 30* dwell and 0* TDC. I also tried 30* dwell at 10* BTDC since that's what's on the sticker for stock timing. That didn't really make much a difference. Maybe slightly.
     
  8. wolffang92

    wolffang92 Well-Known Member

    My guess is I'm not getting enough fuel. Might need a carb rebuild and tuning.

    I'm thinking a bigger power valve, jets, or nozzle on my carb might do the trick. Or maybe some combination of the 3. As far as I know everything on my carb is what it came with stock. It's a Holley 4412-3 500 CFM 2 barrel.
     
    Last edited: Oct 14, 2017 at 2:55 AM
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I think you need to look at the specs for the 1111938 distributor you are using. It has 30-34* of maximum mechanical advance. The reason for the range of 30-34 is that due to the manufacturing tolerances of the day, that particular distributor you have can have 30, 31, 32, 33, or 34*. If you run 12* initial advance, you will have 12* + 30-34. You will have 42-46* of advance when you nail it. No wonder it is pinging. That is why you must use some light springs to set the total advance to 32*. Your initial advance will then be WHAT IT HAS TO BE for that distributor. You HAVE NO CHOICE of initial advance unless you change the amount of mechanical advance.
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Your timing sticker is completely irrelevant now. It only applies if you have the distributor that the stock engine left the factory with.

    With the 1111938 distributor you are using, your initial advance will end up being around 0*. Anything more will over advance the timing at higher RPM, and it will ping or detonate. Be careful, you will damage the engine eventually.
     
    Last edited: Oct 14, 2017 at 7:14 AM
    wolffang92 likes this.
  11. wolffang92

    wolffang92 Well-Known Member

    That definitely makes sense. What doesn't make sense to me is even when I've got it timed at 0* initial it pings pretty bad. 0* initial should put me close to where I need to be, so I was assuming it shouldn't be pinging like it is. I've got that curve kit ordered, though. I really hope it helps the pinging once I set total timing. I just can't wait to get this thing back on the road. I really do appreciate all the help, though. Thanks a ton, Larry.
     
  12. alec296

    alec296 i need another buick

    What do you have the vacuum advance hooked to? 68-69 should be manifold vacuum. Not ported. Try running engine with vacuum advance plugged. See if it changes anything
     
    wolffang92 likes this.
  13. wolffang92

    wolffang92 Well-Known Member

    I have it plugged at the moment, but normally I have it hooked to the port on the throttle plate of my carb. What would be the best way to hook it to manifold vacuum? Probably a dumb question, but I'm still learning how to work on this type of stuff.
     
    Last edited: Oct 15, 2017 at 8:49 PM
  14. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    I would use a MR gasket bushing kit to reduce the amount of mechanical timing.
     
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    All your questions are answered in my Power Timing thread. I linked you to it in post # 18.
     

Share This Page