New User.....engine clatter



New to the board here. I have a 68 Mustang that is stock other than
the petronix set up. The engine was rebuilt about a year ago (just before
I bought it) and runs pretty good. I am just starting to work on restoring my stang to its previous glory. My first question....since I am driving this car frequently aside from additives and timing advance/retard what can I do to get rid of the engine clatter when I am accellerating. I can adjust the timing and idle to almost be rid of it but then the car lags. Any suggestions? I also have a webber carb and clifford adapter but have not had time to slap it on.

Sounds to me like you may have hooked your Petronix vacuum advance to an improper vacuum source. Or maybe a ballast resistor is being used where there should be none. Or both. Or something entirely different. :LOL:
I am using the petronix ignitor and a petronix coil. New wires, plugs. Everything else is stock. Runs great other than the clatter.
check and make sure that your exhuast manifold is tightened...i had this occur to me several months ago and thought it was the pistons clinging on the cylinder walls...check that...thats as easy as it might be...
I have had some experience with your problem. First go back to the basics, check your valve train for proper operation. Is there anything loose or improperly gapped. I dont know if you can adjust your valves, mine does & when I properly adj the setting .017 for intake & .014 for exhaust I noticed a definite improvement. Also not to burst your bubble, but when I bought my car I also was told that its engine was rebuilt. Suffice to say it really wasnt. I had the same engine clatter from my "rebuilt engine", after I had a real rebuilt head installed the clatter was gone-hardened seats I betcha! As far as timing with no vacuum advance(disconnect & plug line for this) 12-14 deg BTDC should be right with your strobe light. Check it out & let us know