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Old Dec 29, 2017 | 11:10 PM
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Default engine knock

1984 c-4 w/cross-fire injection and hyper-tech chip when I jump on it , engine has hard knock like valve or lifter would , but its not. where to look next?
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Old Dec 30, 2017 | 04:23 AM
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Default engine knock

Assuming you've ruled out a rod or lifter going bad have you taken a look around the engine bay? Possibly some bracket or bolt has loosened and under acceleration with the twist of the motor something is moving/hitting ?

Last edited by ls777z; Jan 1, 2018 at 12:12 PM.
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Old Dec 31, 2017 | 04:16 PM
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check and dobble check timing , pull nr one spark plug and find tds. se if the timing mark on the damper match !

Last edited by corvettenorway; Dec 31, 2017 at 04:16 PM.
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Old Dec 31, 2017 | 09:17 PM
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Does it knock with the stock chip in?
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Old Jan 1, 2018 | 12:14 PM
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Default engine knock

Just throwing out another suggestion. What octane fuel are you using?
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Old Jan 1, 2018 | 05:36 PM
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Are you confident that the outer ring on the harmonic damper has not shifted? The rubber can deteriorate over time and miles. Then the ring shifts and the timing mark moves making your static timing off. The ring can also move in or out on the hub. If it moves too far in it will hit the timing cover and knock (bang) on that and if it moves out, it will hit the rotating stuff. Just a thought.
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Old Jan 4, 2018 | 10:44 AM
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If it doesn't seem to be tied specifically to RPM, a bad motor mount caused a knocking (more like a clunking) sound on one of my cars (non-Corvette). Just a thought.
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