Sluggish Acceleration (1970 Electra)

Discussion in 'Street/strip 400/430/455' started by Victor J Washington Jr, Oct 21, 2019.

  1. Stevem

    Stevem Well-Known Member

    My money's on your compression test showing low readings due to a shot timing chain.
     
  2. CJay

    CJay Supercar owner Staff Member

    Sounds like it just needs tuning. A faster advance curve might help. The air flap adjustment, what tom said about drilingbout the pull off slightly to make it "unload" faster. Making sure the carb is opening fully.

    I'm sure it doesn't help that the car weighs 5000 lbs and it likely has 2:93s in it. It's only going to be so fast
     
  3. I'll continue to mess with the carb tuning. I don't think there is much else that can be done with the timing beyond replacing the timing chain. I have a small increment in which to adjust the timing from where it's at. A quarter-turn clockwise retards it and a quarter-turn counterclockwise gives a rough idle and causes hard starting. I didn't use a light when I messed with the timing, because I have an HEI distributor...factory specs are out the window.

    Not expecting it to compare to a drag car, just a bit disappointed in the performance. I've driven these cars many times before and I know what its capable of. Also, I have a 71, which is very responsive off the line. It'll put you in your seat. The 71 was rated lower than the 70 in terms of hp and torque...not to mention, the 71 weighs more than the 70.


    1970 Electra Specs: https://www.automobile-catalog.com/...ck_6gen/electra_3gen_4-door_hardtop/1970.html

    1971 Electra Specs: https://www.automobile-catalog.com/...ick_7gen/electra_4gen_hardtop_sedan/1971.html
     
  4. Schurkey

    Schurkey Silver Level contributor

    Did the resistor wire get eliminated in favor of a 12-gauge non-resistor wire? Low power to the HEI will cause no end of problems.
     
  5. LARRY70GS

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

    You should not touch the timing unless you use a light. The initial timing is what you are adjusting by moving the distributor. Realize that the timing changes as soon as you go above idle. Mechanical advance and vacuum advance add timing. For some reason, lots of old car owners have a really rough time understanding ignition timing, so much so, that I wrote this post many years ago,

    http://v8buick.com/index.php?threads/power-timing-your-buick-v8.63475/

    Indiscriminately turning the distributor is quite possibly one of the worst things you can do, especially with a non stock distributor, and it really tells you NOTHING because you don't know where the timing was, or where you are moving it to, or what it will go to at higher RPM. If you get a light and learn how to use it, you can set your maximum advance accurately so you don't hurt the motor. Your ignition timing is likely your problem, either too much or too little. The big cap HEI can cause problems with the adjustment because as you've found, the big cap hits the front of the intake limiting the adjustment. It then becomes critical to install the distributor correctly. If you don't, you may not be able to adjust it. That isn't even mentioning that the advance curve in that distributor might be all wrong for your engine. Distributor specs vary greatly depending on the year and engine they were originally installed in.
     
    Last edited: Oct 23, 2019
  6. Even after reading the information in the post you provided the link for...I must admit, it's a bit confusing. As mentioned earlier, I'm a newbie. Just starting to learn about the internal mechanisms in an engine. My mechanical knowledge is pretty basic. I'm willing to tinker with a few things here and there, but when it comes to something as intricate as this, I'm not that confident that I won't mess it up. Don't want to destroy my engine. I'll leave that to the professionals.
     
  7. LARRY70GS

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

    Yes, you have to understand the basics, otherwise you should not touch it. BTW, if you fill out your profile fully with your location, there might be someone in your area willing to help. Might be a few blocks away and you'd never know it.
     
    JStov likes this.
  8. When I do the compression test, does the ignition need to be disabled or does that only apply to newer vehicles?
     
  9. Gary Bohannon

    Gary Bohannon Well-Known Member

    A stuck heatriser valve will
    1 kill the power
    2 over heat the carb and engine
    3 make you spent 1000 dollars trying to restore power.
    Exhaust pipes that are original laminated will buckle inside and do the same thing. You cant see this, you have to know about it and drop the pipes from the manifold. Roll a golf ball through or just replace all the piping and eliminate all doubt.
     
  10. Schurkey

    Schurkey Silver Level contributor

    Best to disable ignition, so that the ignition coil isn't trying to spark. Safer, too.
     
  11. Listening to the engine when I punch it, I'm inclined to think that could possibly be the issue. It sounds as though the engine is bogged down (muffled)...doesn't sound normal at higher rpms. That's exactly what I don't want to do...spend 1000's to find out it was an inexpensive fix. I'm trying to start with the cheaper options before going into the engine components.
     
  12. telriv

    telriv Founders Club Member

    When doing a compression test ALWAYS have the throttle wide open. Can't pump as much air with the throttle closed.
     

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