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fatbass · 04-12-2023, 01:35 PM

Way back in the early '80s I helped rebuild the Quadrajet on the 366 big block in the company's '71 C60 drill rig. We placed it on the engine and had the throttle cable on backwards somehow so that when we started it up it went straight to redline and started knocking loudly.
We thought for certain it was a rod so we jacked up the engine enough to get the pan off and the bottom end was as tight as ever. So we pulled the carb off and noticed one of the base screws on the underside was missing. Must have forgot to tighten it is all we could think was the cause.
We pulled the passenger side head off and that screw was smashed flat in the top of #4 piston right between the intake and exhaust valve reliefs. We pried it off the piston (leaving an imprint of the screw), penetrant inspected the piston in place, no cracks!
Slapped the engine back together with a new head gasket and had no further issues for the next year I was there.

04-12-2023, 01:35 PM	#29
fatbass Registered User Join Date: May 2012 Location: South Ogden, Utah Posts: 172	Re: help, dropped nut into intake Way back in the early '80s I helped rebuild the Quadrajet on the 366 big block in the company's '71 C60 drill rig. We placed it on the engine and had the throttle cable on backwards somehow so that when we started it up it went straight to redline and started knocking loudly. We thought for certain it was a rod so we jacked up the engine enough to get the pan off and the bottom end was as tight as ever. So we pulled the carb off and noticed one of the base screws on the underside was missing. Must have forgot to tighten it is all we could think was the cause. We pulled the passenger side head off and that screw was smashed flat in the top of #4 piston right between the intake and exhaust valve reliefs. We pried it off the piston (leaving an imprint of the screw), penetrant inspected the piston in place, no cracks! Slapped the engine back together with a new head gasket and had no further issues for the next year I was there. __________________ '71 C/20 350/T350.