[Rikarus]

SO my friend has a 73 Challenger, 440 engine, 4 speed, he had it restored.....didn’t do the work himself and cant tell me much about the motor except it was built by a racer...(weak I know)


It's a strong 440 and runs like a madman, I went in and played around to make sure the timing is on, or reasonably close as I can guess not knowing cam/compression, etc.


When he lets out it will backfire in the exhaust pipes after it's warmed up. It's like some unburnt a/f mixture is getting in there and when it accumulates enough....BAM!

He is running a carter carburetor, and stock ignition.


I am brainstorming a bit to figure out what would be the cause, timing, ignition system, valve lash, the crappy (I mean Carter) carburetor, any thoughts?