Backfiring and no power

Discussion in 'Troubleshooting & Diagnosis' started by WiggyB31, Sep 26, 2019.

  1. dave@ztech

    dave@ztech Veteran Member Lifetime Gold Member

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    I hope fuel wash didn't ruin that engine at break in. You seem to be on the right track now, good luck!!
     
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  2. flht99b

    flht99b Veteran Member

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    I assume the cam in your engine is a flat tappet hydraulic. Popping from the carb indicates an intake issue. You could have an intake valve adjusted to tight. I no longer adjust hydraulics with engine running, instead do each cylinder at TDC on compression, adjusting them to 0 lash and then add the 1/2 turn of preload per cam manufacturer.
     
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  3. xten

    xten Veteran Member

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    Do you have the stamped steel rockers? The adjusting nuts wear over time and need replaced or they won't stay put and will loosen on their own. If you have roller rockers I would highly recommend poly locks. But it does sound like an intake valve problem (too tight, bent, burnt) or an intake lobe on the camshaft.
     
  4. budro6968

    budro6968 Veteran Member

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    My 2 cents. Redo the Dizzy set up. If you have it wired to run at 180 out, sure you can get it to run. The thing is trying to set timing will probably be an issue B/C the Vac advance can will hit the engine or Fire wall depending on which way you need to go to get timing set.
     
  5. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    ^+1
    I don't know why any paid mechanic would reroute all of the spark plug wires when it takes far less effort to restab the distributor to do it the "right" way.
     
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  6. flht99b

    flht99b Veteran Member

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    Agreed. But I cannot tell you how many "pro built hot rods" as well as daily drivers that have the distributor incorrectly installed and the spark plug wires moved to make it work.
     
  7. WiggyB31

    WiggyB31 Member

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    20191001_200302.jpg 20191001_200322.jpg So I got one of the heads off last night (had to work late) and I must say I've see better heads on an older engine. To say there's less than 10 hours of run time on this supposed to have been fresh rebuild there's a lot of carbon on them.
     

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  8. flht99b

    flht99b Veteran Member

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    Looks like it was running very rich.
     
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  9. WiggyB31

    WiggyB31 Member

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    I would say yes it was when it had the dual carb setup on it (like that when I got it) so damage had been done clean them up and start new.
     
  10. WiggyB31

    WiggyB31 Member

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    20191002_183816.jpg 20191002_183831.jpg Ok got the other side off and it's not as bad. Off to the shop tomorrow and see what comes back. May be over kill but I want to make sure it's right. If the check out ok I'm going to pull the cam and fix that 180 out crap too.
     

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