Power Timing your Buick V8

Discussion in 'Buick FAQ' started by LARRY70GS, Jan 2, 2005.

  1. JDempy

    JDempy Member

    I have a question.....

    I have never messed with the timing on my 72 riv 455 other then to check it. Stock motor, original distributor with a acell points eliminator.

    I was reading this thread so I started playing with the timing. Checked all the parts and both vacuum and mechanical advance were working properly. Fresh tuneup and carb is set well. Car ran very nice but I felt it was underpowered.

    Timing Was set a 4 degrees (factory for 72), bumped it to about 10. Immediately improved power.......so I ordered the crane kit as listed in the thread.

    Installed new springs (1 blue 1 yellow) per cranes paperwork that’s all in at 2600. Once again immediate power increase with a much stronger mid range.

    I’m pissed I didn’t do this along time ago!

    Car is no drag racer, I’m sure the rear end is a 2 something ratio and of course it’s a riviera so it’s heavy as heck

    So after all that......Should I go lower on the springs (silver silver all in at 2200) or would I be getting into idle timing?

    Would a stock 72 455 even benefit from a change at this point?
  2. johnriv67

    johnriv67 Well-Known Member

    For a heavy car like that, 2600 rpm is just where you want to be. Definitely wouldn't go any lower.
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Stock distributor for the 1972 Buick 455 was the 1112110. Look at the specs, Total amount of mechanical advance is 14-18*. So at 4* initial timing, the most timing you could have would be 18-22*, far short of the 32* that makes best power. I would set your total timing without vacuum advance to 32*. Then see what your initial timing is. I'd leave it in at 2600, you don't want any mechanical advance in at idle.

  4. JDempy

    JDempy Member

    Thanks for the info and the quick responses.

    I’m going to use my dial back light to get it to your recommend 32 tomorrow.
    Darron72Skylark likes this.
  5. MrSony

    MrSony Well-Known Member

    Finally got off my lazy ass and did the limiter plate mod. Car is definitely peppier. I've got about 8* of vac advance right now, 12 initial, 22 mech in by 2600. 42 total. Definite difference. If I remember I was getting something absurd like 55* of total timing before hand with the unencumbered vacuum advance.
    Each notch is 2* on the plate right, or thereabout?
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Yes, you should verify that with a light.
    MrSony likes this.
  7. MaximG

    MaximG New Member

    Hi Larry,

    this is the best explanation of timing I have seen to date. However I do not have the tools or know how to adjust all these parameters accurately. Would I just adjust the existing setup a couple of mm each way and drive the car to see the results?
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I would not touch it without the right tools. Leave it alone until you can do it right. You can do more harm than good.
    MaximG likes this.
  9. MaximG

    MaximG New Member

    Ok thanks Larry
  10. breakinbuick11

    breakinbuick11 Platinum Level Contributor

    Just bumping up the most informative thread on any forum anywhere. Got my pro-touring build timed correctly and feel like I added 30-40 HP. It cold starts without a choke much better now. Thanks Larry!
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Glad it helped Louie. I still link this thread to plenty of guys to this day.
    breakinbuick11 likes this.

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