Is this the correct distributor for my 1969 GS400?

Discussion in 'The Bench' started by Patent Pending, Aug 9, 2020.

  1. Patent Pending

    Patent Pending Well-Known Member

    I have have been fussing with the timing on my 69 GS400 on and off for a few years now. I put a Pertronix setup in it. Works great. I have the timing set so it starts and runs fine (I used Larry's Power Timing Thread), but something doesn't seem right with the timing. I purchased the car a few years ago and the documentation that came with the car is spotty. I know it has some sort of mild/moderate cam, and I know it has TA 1.65 roller rockers and the heads were removed and ported, so I know it is not stock. Initial timing works well at about 15deg. However, the total timing is around 50-52 degrees, which doesn't seem right to me. It seems way too high. The mechanical advance seems way too much. Nothing in the distributor appears to be worn. The only thing I can conclude is that the actual distributor is not the correct distributor for this motor and that someone before me used the wrong one(and I have spent a few years trying to make something perfect that never will be). I know the correct part should be 1111335, but I cannot find that part number on the distributor anywhere. All I find is a patent marking PATENT 2769047. So, I know it's an original GM dizzy, but perhaps not for this motor. I'm attaching a few pictures. If someone can tell me if this is the correct distributor and if it isn't what it actually is for (out of curiosity). Thanks! IMG_20200809_150706 (1).jpg IMG_20200809_144635 (1).jpg IMG_20200809_144631 (1).jpg
  2. Nailhead in a 1967

    Nailhead in a 1967 Kell-Mnown Wember

    thats the delco remy patent number
  3. gsfred

    gsfred Founders Club Member

    The number should be on the outer edge of the distributor, below where the cap meets it.
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Are you measuring the total timing including vacuum advance? The correct distributor, 1111335 has a maximum amount of mechanical advance of 30-34*. If you set the initial advance at 15*, why are you surprised that you have so much total, 15 + 34 = 49? That distributor is not the best one to use anyway. Get the actual part number on the circumference.


    Last edited: Aug 9, 2020
  5. Patent Pending

    Patent Pending Well-Known Member

    All, thank you for the responses. I thought the part number was on the circumference, which is where I looked, but I didn't see it. I will take another look as perhaps I overlooked it and was just having a senior moment. Larry, the timing measurements were without vacuum. I plugged my manifold vacuum before taking the readings. That said, I see from the manual section you posted that getting to about 50 is not crazy, but mine did go past that. I saw so many posts regarding 34-36* total timing for BBBs that it just seemed off to me, but I guess that 34-36 works if initial timing is closer to zero. My motor won't run at 0* with the cam that is in it. Regardless, I will see if I can find a part number.

    Larry, you mentioned that the 1111335 part is not the best one to use anyway. If I do decide to change it, what is the best one to use? Thanks!
  6. Daves69

    Daves69 Too many cars too work on


    You are probably missing the bushing the limits mechanical advance. It is located on the pin in the slot just below one the spring attachment pins. The bushing is included with most advance kits.

  7. Patent Pending

    Patent Pending Well-Known Member

    Thank you! I think that's my problem. I noticed today that the pin that sits in the advance plate notch has no bushing on it. It's just the pin sitting in the slot, which sure does allow a lot of mechanical movement of the rotor. I will pick up a bushing kit and see if that does the trick, limiting my mechanical advance to something reasonable.
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes, try a bushing for sure. The best distributors to use are the 1971 and 1972 distributors. 350 and 455 distributors for those years had very little mechanical advance which lets you run a lot of initial advance. Most moderate cams need that.

    1971IgnitionSpecs.JPG 1972IgnitionSpecs.jpg
  9. No Lift

    No Lift Platinum Level Contributor

    What number is on the part that the pins for the weights are on? Underneath where the weights go. That pretty much tells you how much advance the distributer will have. It will say something like X18, X26, X30(not sure what X will be). The last two digits are pretty much how much mecvhanical advance the distributer will have as long as the bushing is in there. The part in the middle has a number on it and I believe it makes a difference on how the timing kicks in but I don't think it makes a difference in total. If your plate has X26 or more it will be tough to run much initial. Going by what you say probably X36.
  10. Patent Pending

    Patent Pending Well-Known Member

    All, thank you again for the super-helpful suggestions. I was able to get back under the hood. After some cleaning and degreasing, I was able to uncover the distributor part number. It is 1111285, which looks to me like it's from a 1968 motor (my car/motor is 1969). I also noticed that there is no bushing at all (rubber or otherwise) on the mechanical advance pin on the underside of the distributor. Based on the quick research (please correct me if I am wrong) the mechanical advance limits for the 1968 part are the same as the 1969 part. I have a Crane adjustable vacuum canister so if the difference was in the vacuum advance it is a non-issue. So, it seems to me the short term requirement for me is to at least get a bushing in there to limit the mechanical advance which is clearly way too much now. Longer term swapping out for a later model year 71/72 distributor like Larry suggests. BTW, if anyone can recommend a source for good rebuilt distributors, please pass the info along. I just weekend drive the car. I don't race it and it's not a show car.
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

  12. BuickV8Mike

    BuickV8Mike SD Buick Fan

    I had mine done. Best performance upgrade for the money possible.
  13. 2manybuicks

    2manybuicks Founders Club Member

  14. Patent Pending

    Patent Pending Well-Known Member

    Thanks. Definitely going to find a correct year part and then have it rebuilt or recurved.
  15. Patent Pending

    Patent Pending Well-Known Member

    Just wanted to close out this thread and thank everyone for the good advice. I ended up buying a 1111335 distributor from another forum member, and sending it off to Ken at Everyday Performance for a rebuild and curve. Kudos to Ken. He did a great job on it. Looks like new. I popped it in and the engine fired right up. Power timed it per Larry's excellent thread, made a few other carb adjustments while I was at it, and went for a nice drive. Initial timing is at about 14 and total is 35. Runs great. Huge improvement.
    techg8 likes this.
  16. 69_GS_400

    69_GS_400 Well-Known Member

    This sounds all to familiar. I was running mine with 17 degrees initial. I have a 69 with a ta 118 cam. Stock distributor that has been recurved and rebuilt. Part number is correct as mentioned above 1111335 unless you have an extremely early build date. I backed mine down to 9 otherwise I’m barely idoling. No pinging or denotation at heavy throttle. I know it’s still over 34 but it works. The only thing that I still have a bit of troubles with on a 80+ degree day is temp rising at idol. And yes I have all the good stuff sufficient for cooling and all the correct parts. I’m sure it’s due to the the timing still being slightly high and no vacuum advanced hooked up.
  17. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Problem with that is you might not always hear the abnormal combustion. It's also possible someone else modified the distributor in 50 years. Why not just measure the maximum advance you are running? The 118 cam closes the intake valve late, so running compression is much less than you might think. You may be getting away with more advance for a number of reasons. Your temperature problems may be caused by idling at 9*. Try vacuum advance connected to manifold vacuum. More advance at idle will cool it down.
    69_GS_400 likes this.
  18. Patent Pending

    Patent Pending Well-Known Member

    I had the exact problem that Larry describes. My old dist did not have the mechanical advance limiting bushing and my mechanical timing was way way too much. I could not hear the abnormal combustion, but I had a few passengers who could hear it and pointed it out. That's what ended up starting me down the road to replacing my distributor with a correct year piece that was also properly curved. Night and day difference in drivability as well.

Share This Page