problem it kept going slower??

Discussion in 'Race 400/430/455' started by Dubuick, May 10, 2004.

  1. Dubuick

    Dubuick CMDR Racer

    last week end I was racing 1/8mile on friday night I made 7 passes and between 6.79 and 6.84 and mph of 99.3 to 100.4 the short time of 1.45 and 1.46 on all the runs.......Saturday night same air 700' above sea level first pass 6.82 99.3mph by the third pass first round it went 6.90 at 98mph 1.52 short i made 6 more runs by the last pass it went 6.99 at 97mph 1.57 short......every one else was running the same all day on air change or head winds the motor seem like it didn't want to rev up to 6000 were i shift....would the valve springs go way the quickly? I checked the valve lash and if any sping broke but it all looked good the only thing i found was the msd cap was worn on the inside were the center of the rotor is....I'm stumped?????

    Any ideas would be great thanks...
     
  2. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    Make sure the trans fluid is not burnt.....
    What Carb?Jetting?
     
  3. Dubuick

    Dubuick CMDR Racer

    the carb is 4150 holley hp 1000 cfm the 87 and 88 I think ..how do you check the trany fluidn to see if it is burnt?
     
  4. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    Smell it.....Symptoms could be a bad converter.
    What converter are you running?
     
  5. Dubuick

    Dubuick CMDR Racer

    my converter is an ati 4400 tree master i'm going to change the fluid soon i haven't done it in two seasons
     
  6. stage2man

    stage2man Well-Known Member

    rear could be going away
     
  7. buick535

    buick535 Well-Known Member








    :jd: What? you have'nt changed the trans fluid in 2 seasons?
    Are you nuts? When running a high stall converter, the fluid temp gets astronomical, regular ATF will be long since gone after very few runs. Jim Burek
     
  8. Jim Weise

    Jim Weise EFI/DIS 482

    Not sure what your talking about Jim...

    Since I used to race a lot (several hundred passes a year) and of course we monitored every fluid temp in the car....

    I had an 8" ATI converter, stalled at 5100 rpm on the brake. Trans brake car.. so it sat on the line at 4500 on the air throttle..

    NEVER in all that time, over several years of racing, did I see trans fluid temps in excess of 170*, on the hottest day, even during "round robin" type late round eliminations.

    Good converters don't hurt the fluid, especially in drag race applications. Converters that are doing something they shouldn't be doing, generate heat and destroy the fluid.

    I recall this distinctly, because on those few occasions that I did see trans fluid temps in the 160-170 degree range, I had to change the dial in on the car, as it would slow down about 3-5 hundreths..

    I now run a much better fluid, with improved lubricating qualities and higher shear strength than we used to, but not because of passenger car fluid issues or failures.. That fluid is in Sweey's 9 second GS, and that car has never gotten the trans temp gauge over 140*..

    As to the problem at hand here.

    Cut the oil filter open, and make sure the motor is not going away.. covering the basics is your first step here.

    JW
     
  9. Dubuick

    Dubuick CMDR Racer

    So far the trany fluid smells like trany fluid as for the motor going the oil presure was the same all day long but i'm gona cut up the filter tomorrow and change the trany fluid....But the other thing that happened was before the problem started the car pop becuase it was cold and blow of a rubber vacuum plug off and i made a pass with it off i noiced it after the pass due to poor idle and at the end it poping thought the exhaust I put it back on and then it started to feel flat above 5000 rpm like it does want to rev.also would the cap being worn cause that?
     
  10. stage2man

    stage2man Well-Known Member

    I had the same thing happen to the BB regal last year. Keep slowing more and more until it got to where it just wouldn't rev.. The 9" ford rear finally let loose. That was it.

    Good luck!
     
  11. badbuik

    badbuik Well-Known Member

    What Carb. are you running? You mentioned a "pop", I think I would take the carb. apart and check it out. Maybe a vaccuum leak somewhere else.
    Gary G.
     
  12. BirdDog

    BirdDog Well-Known Member

    Easy stuff first...check out that dist. cap. If there is a problem there, then it could certainly affect your spark current; therefore, affecting your performance.

    I thought if your torque converter was going away you usually experianced higher RMPs through the traps??
     
  13. buick535

    buick535 Well-Known Member



    What I am talking about is quite a few race converters I have seen inside of at some of the torque converter seminars I have been to over the years. The inside of the converter shows signs of burning, they describe it as a flash fire in the converter, caused be excess heat, usually from sitting on the line too long against a tranny brake.
    I have also watched several race cars over the years literally burn down the tranny while sitting on the line under full throttle trans brake engaged conditions waiting for the lights to come down. I've seen this when the first car, usually the faster one stages first, the other guy is not even in the beams yet, the first guy engages the brake and sits there while the other guy stages, then still has to wait for the spot difference, by the time his light comes down, smoke pours out from under the car as the tranny went into melt down mode.

    But the main concern here is monitroing the trans temp in the cooler out line, since the oil goes from the converter to the cooler , then back to the trans. With the temp sensor in the pan, you don't see the temp spikes as much since the hot oil has to come back into the trans and then heat up all the oil in the pan as well as over come the heat syncing of the trans itself.
    So in a 9 or 10 second run, you may not see a big change in temp reading in the pan, but the oil out of the converter can still be pretty hot.
    Sort of like when the water temp may be 190 degrees behind the thermostat that is set ot open at 190, but the radiator temp is still very cool , like 130 or less, once the t. stat opens , the engine temp drops, but the fact still remains that the coolant still got to 190.
    Anyway, that's all I was getting at.
    And I understood your hidden message, you never change. Jim Burek P.A.E ENTERPRISES
     
  14. Dubuick

    Dubuick CMDR Racer

    Everyone thanks for the ideas to check things so i change the cap rotor checked the valve adjustment and springs, cut the oil filter open ( nice and clean ) I took the carb apart blow it all out, and still seems to run the same the plug wires were they plug into the cap are all green and black so gona change them, and gona try some new power valves because i'm having idle problems still. when i put the carb back on the car kept back firing up the carb and when i got it running i would set the idle at 1200 and it would kept wanting to stall turn it up to 1900 it stay there for a little bit then drop down to 900 and stays there till i hit the gas again goes back to 1900 it is driving me crazy!!! no matter what i do with mixture screws it doesnt' help what size power valves should i use the carb came with 6.5's I have 12:1 with 508s cam also what should i have for fuel presure?

    Thanks
     
  15. Dennis Halladay

    Dennis Halladay Well-Known Member

    I used to see a problem similar to this every spring with my old 850 holley. Carb main body to base gasket would swell and alter vac. signal. It is a cheap insurance policy to replace all gaskets in the holley carb after setting over the winter to prevent problems like this. Mine seemed to run fine at higher RPM just wouldn't run low RPM and idle walked all over. Sounds like more than one problem here, I would also look into ignition problems as well. The center of the cap can take a beating if there is extra resistance downline of the cap, take a good look at your wires.
     
  16. bgs455

    bgs455 OIF OEF HOA ONE

    Have you checked you're timing?
     
  17. killrbuick66455

    killrbuick66455 Well-Known Member

    I would deffenitly look at the power valve you should have no more than a 4.5 power valve in that carb.. i have the same carb and it happend to me but... you must check what idle vacuum. Its important cause that will indicate what power valve to use..With that 508 cam your not pulling alot of vacuum..maybe 8 inches or less so you would use a 3.5 powervalve thats just an example...That will help your idle problem but as for slowing down i doubt it...
     
  18. Dubuick

    Dubuick CMDR Racer

    I had Noticed that my wires were they plug on the cap are like all black so i have to change them and put the cab back together then i'll check the timing what would cause the timing to change if the distirbutor is tight? also when i started it to move it the other day it poped thought the carb again so i'm starting to think the timing as moved..
     
  19. bgs455

    bgs455 OIF OEF HOA ONE

    Are you running the hi vol-pressuer oil pump? If so pull the distributor and look at the gears.
     
  20. Dubuick

    Dubuick CMDR Racer

    yea i do have a hi vol. pump and i have alot of oil presure when i first was running the car I had to cut the sping down to lower the presure so that is a good point i'm gona check tonight thanks
     

Share This Page