383 stroker timing/performance and temperature

Discussion in 'Troubleshooting & Diagnosis' started by erhan ergin, Apr 25, 2020.

  1. erhan ergin

    erhan ergin Member

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    I dialed the idle timing down to 18 degrees.
    I checked PCV valve and it is fine
    I sprayed carb cleaner around the intake, around vacuum lines and no change in idle.
    Anyone can suggest a dyno tuner around Austin TX?

    Thanks
     
  2. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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  3. erhan ergin

    erhan ergin Member

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    Yeah they came up in my google search as well. They seem good but like you said they also look quite expensive.

    Thanks
     
  4. erhan ergin

    erhan ergin Member

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    Based on earlier feedback and what I read on the web, I opened the carb metering block and checked the power valve size. It is the standard 6.5 that came with the carb. I think this is the reason for the rich running and possible power issue down low. I ordered a 2.5 and a 3.5 valve. Hopefully this will do it.

    Thanks
     
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  5. G72Zed

    G72Zed Veteran Member

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    I have rebuilt and tuned several of these "brawlers". Some had the same issues you are experiencing. I found the IAB/HSAB where inverted in one case, one did not have the kill bleed's (anti siphon) drilled completely through. I have also found that the IFR that are in the high set position where in the 36+ range and way to big in many of them. Misaligned base to main bodies have also come up.

    If the PV cavity is not all wet, chances are you do not have a blown power valve. Going to a lower PV will generally cause a lean miss when going from the idle/cruise circuits to the mains as the PV channel is connected to the mains only, and your mains are not active in the idle/transition area. I have a test fixture that I use as I have found the PV ratings to be off sometimes.

    Also, check for trash and aluminum/brass filings, some are bad. Check your carb actual specs to see what you have, they are:

    Primaries- 70 MJ, 6.5 PV, 31 shooter
    Secondaries - 76MJ, NO PV, 31 shooter
    IAB - 71 (These are the outer bleeds)
    HSAB - 31 ( inner bleeds)
    The Emulsion pak should be checked also, just going from memory it should be 28/28/plug/28 if a 4 channel? I do not have my files with me.
     
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  6. erhan ergin

    erhan ergin Member

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    Thanks for the data, I was wondering what standard jets were there and if anyone got in to these carbs before me. From the way the primary metering block was stock on the body I think it was not opened before. In fact I think prev owner replaced a holley double pumper with this and never tried tuning. The primary float was way high and the A/F were all over.
     
  7. G72Zed

    G72Zed Veteran Member

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    The AFR's being all over sometimes comes from the "high set" IFR.

    And if the AFR's are all over on idle, that could point to other issues like big cam, high overlap,reversion-pressure waves, leaks and a host of other things that sends the AFR meter in convulsions.
     
  8. Louich

    Louich Veteran Member

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    How lumpy does it idle?
    Sounds like you have a race car cam in a street car /'compression engine.
    Just went through this with a guys big block.
    Torque moves heavy cars. Big cams sound nice but function needs to match. A lot of people seem to think they know more then the cam companies that have a few years experience behind them.
     
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  9. nova75mike

    nova75mike Veteran Member

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    Dont mean to hijack the thread, but I have a question on the Brawler carb comment. Is there a history of these carbs being questionable? I have a 385 in my Camaro as well. 11 to 1, Howards hydr roller (240-246 @ .050 with a 110 cl) AFR 195 heads and a street warrior air gap dual plane. on the dyno this thing made over 500 hp and darn near 500 ft lbs. ran great once a few issues were solved. Put a Brawler 750 DP on it in the car. this thing runs SO pig rich I cant stand to be in the garage with it running. fouls plugs like nobodys business, even tried E3 plugs. had a buddy from the dragstrip come down and tune it, this guy has been tuning and racing Holley carbs almost as long as I've been alive (50 this year). it will idle at 900 in park, 800 in gear. changed idle air bleeds to lean it out. cant get more than about 7-8" of vacuum out of it. pig rich. 15 degrees of timing at idle and 34 total, do not have the vacuum advance hooked up. MSD 8365 ditributor, coil, 6AL2, 8.5 wires, everything is new and works. tested for vacuum leaks, none. could I be looking at a bad (questionable) carb??
     
  10. Louich

    Louich Veteran Member

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    E3 plugs are garbage!
     

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