Power Timing your Buick V8

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

  1. LARRY70GS

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

    Sounds like you are running lean. Put a vacuum gauge on it. Make sure there are no vacuum leaks. You should be able to get all the advance in at 2500 RPM or less and have no ping at all with 32* total and no vacuum advance. Work with the initial and total timing until you eliminate the ping. Forget about the vacuum advance until then. Make sure the bushing didn't fall off.
     
  2. jtcasper

    jtcasper Well-Known Member


    I will check the vacuum and disconnect it. The bushing is still there I checked the total again last night to be sure of where I was at. When you say it is lean, are you thinking that I need to change some jets or just timing right now.

    Thanks, Joe
     
  3. LARRY70GS

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

    If you have a vacuum leak, it will run lean. The vacuum gauge will give you a good indication. If the motor is all stock, it should show at least 17 or 18" of vacuum at idle fully warmed up.
     
  4. jtcasper

    jtcasper Well-Known Member


    I checked the vacuum tonight. The gauge moved kind of erraticly, but was between 16 and 20. That was taken off of the manifold right behind the Carburetor. It idles a lot better with the vacuum advance connected, is that because I am getting the 10* or so degrees of advance at idle.
     
  5. LARRY70GS

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

    You have other problems. The gauge should be quite steady. Is it occilating rapidly or slowly? The stock vacuum advance cannister will supply between 14 and 18* at 16" of vacuum. Here is a good article on diagnosing engine problems with a vacuum gauge.
    http://www.fordf150.net/howto/diagnoseengine.php
     
  6. jtcasper

    jtcasper Well-Known Member


    The gauge was oscilating very rapidly. Looks like I have some work to do.
     
  7. LARRY70GS

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

    possible valve problems or dead miss.
     
  8. jtcasper

    jtcasper Well-Known Member


    Maybe I should do a compression check. That would help to find a valve problem wouldn't it.
     
  9. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Yes it would..
     
  10. LARRY70GS

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

    Absolutely, a leak down test would be even better.
     
  11. jtcasper

    jtcasper Well-Known Member

    Thanks guys. My dad is a retired mechanic so he has most everything I need. I know about doing the compression check, but not so sure about a leak down test. I will talk to him about it.

    It looks like my timing problem is not going to be solved to soon, now that I have bigger problems to fix. The weather will start getting bad here so I will probably take the next few months to do some work to the car I have been wanting to do. First off will be the motor.

    The car was given to me by my father-in-law who bought it from my best friends dad about 6 years ago. He was going to donate it because he never used it, so I really don't have a problem putting money into it. For those 6 years the car probably only got about 200 miles put on it.

    When I picked the car up from him, it had a bad water pump. I am now wondering if it got hot and that is causing some of these problems.

    If I have time this weekend I will do a compression check and let you know what I find. I cannot tear into it too much, cause I am in the middle of changing insurance companies and I need to be able to get the car to an appraiser.

    Thanks for your help everyone.

    Larry you are awesome, I really appreciate the help.


    Joe
     
  12. stagedgs

    stagedgs 1967 GS400

    I don't know if this holds true for all areas of the country, but Sears has their Craftsman dialback timing light on sale this week. Normally $69.99 on sale for $49.99. Plus, if you are a Craftsman Club member, you'll get another 10% off (if not, sign up!). Quite a deal, check it out!
    (Sorry about the plug for Sears) :rolleyes:
     
  13. BuickBuddy

    BuickBuddy Registered V8 Offender GK

  14. justinsinternet

    justinsinternet Bad Buick on the Block

    70 455 riv

    What do you use to weld a bead in the slot ?

    I adjusted the vaccum advance and put a plastic peice on the pin lighter springs.

    Initial advance is 7

    Total is 33

    My problem is i still ping all the way through , I cant open 4 barrel at all or it pings . I have messed with distributor over and over again .

    I am at this point where i dont know what else to do , but try the weld and keep adjusting the vaccum advance .

    Any 1 in orlando want to help?

    Or what else should i try? New dist.

    Thanks for any help!!!

    Justin
     
  15. LARRY70GS

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

    Justin,
    You may think you have 33 total, but the distributor may have more in it and advance more at higher RPM's. What springs are you using? The ones in the Crane adjustable vacuum advance kit(3 pair) are ideal. The 2 lightest springs(yellow) will bring all the advance in by 2000 RPM or lower. Makes it easy to check your total. Also, forget the vacuum advance. When tuning, work on one thing at a time or you will make yourself crazy. Disconnect and plug the vacuum advance. Once you get the good springs, adjust your total and make some full throttle runs. You don't want any ping with your advance in as early as possible (under 2500 RPM) Just because someone else runs 33 or 36 doesn't mean your engine will want that much. Find out what your engine needs. Usually it is somewhere between 30-36, but a stock engine may want no more than 30. Find out. Once you have the mechanical figured out, then limit the vacuum advance cannister to no more than 8-10*. Make a block off plate. All the info you need is in this thread. look at the pictures in the beginning.

    Not sure what kind of welding they use to fill the slot. Maybe JB Weld will work, I'm not sure, but you need to take the distributor out and apart to do it right.
     
  16. justinsinternet

    justinsinternet Bad Buick on the Block

    Thank you Larry for your info , i followed everything on this since you first posted it . Just never really messed with it just put in real heavy springs and that was fine until now , I am ready.

    Ok i have the crane spring set and the lightest installed ,thats where i am gettin the 33* at, i beleive its fully advanced around 2000 or so rpms.

    I made a block plate for the vaccumm advance travel and it seems to work , maybe i need to close the gap alittle bit more .

    I time it with the vaccum off , i will leave it off and make some wot runs and see what i get . I will also try jb weld , dont know why i didnt think of that before ?

    I guess i need to go around 30 or so . The peice of rubber i put on the pin nearly cuts the travel in half , i was amazed that it went to 33 i thought it would be around 20 or 25 . Alittle more filler material like 1/16 of jb should do it .

    When i get all the ping out i can start adjusting vaccum advance then.

    Thanks
    Justin
     
    Joker200 likes this.
  17. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    10 degrees measures just under 1/8". So if you use a 7/64 drill bit to measure the gap, that should limit you to 10* vac advance.
     
  18. goshawks00

    goshawks00 Well-Known Member

    I have read and re read this post about making an adjustment plate for the vac can and understand the principle here --- well sort of<G> My question is --(btw I have an Accel adjustable vac can, ready to install) with the forementioned stop added-- what I don't see is what the can's adjustable spring should be set at. Should it be screwed all the way in the can or all the way out?
    Barry
     
  19. LARRY70GS

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


    The spring controls the rate of vacuum advance. Use the adjustment to dial out part throttle ping. The stiffer the spring adjustment is, the faster the advance will pull out when you get on the car. You don't want it too stiff though. You should adjust it so that at 40 MPH in 3rd gear, it doesn't ping when you load the engine.
     
  20. BigBlock68

    BigBlock68 Love that old car smell.

    Ok, I'm real confused after reading all this, but I'm gonna give it a shot to understand.

    Let me start with what I've got. Stock '68 GS400, points distributor with a Pertronix Ignitor II, put back at stock timing. From what I've read, I need the Crane Cams kit for the springs, and maybe the Mr. Gasket for the bushing for the pin, unless I can make a plate or use screws to stop the travel of the pin?

    From there I'm so utterly lost. I can set initial timing, no issues there, and I'm pretty sure I understand how the vacuum advance works. But the mechanical advance has me confused, how do I set it?. Can someone please tell me what I'm not understanding.
     

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