Starting to sound like the ping you get from a blown head gasket? Not a timing issue? Check your coolant or drop some oil, make sure there is only coolant or oil in there and no mix.
2 questions 1. tapping sound?? as in maybe the rocker arms hitting the valve covers?? or something loose?? 2. what compression are you running in the engine...?? if it is a big compression then you may need some octane in it.... jsut a couple things to explore
Set it to 6 degrees as a starting point and increase the idle speed accordingly by turning the idle set screw clockwise. Unless you have a high compression engine, it should not "ping" with 8 or 10 degrees initial timing. The distributor may need recurved or replaced if it's advancing too much...
I have tried 87,91,92 and 112 octane,I have set the timing at 0*-20* initially and no change.It only occurs under load not at idle and only does it from 3/4 to full throttle you can let out of it a bit and it will stop.I have tried switching the plate in the distributor from 30* to 20* and no change. I have thought it may be going lean but the tapping at idle has me suspecting a valvetrain problem but Im unsure if the will cause a ping or sound like one.What should the valve lash be set at? I check the oil regularly and it shows no sign of coolant but I do need to check the coolant.The plugs look pretty good so............
If adjusting timing has no effect, what kind of shape is the carb in? Could be too lean, could be vacuum leak... tapping at idle isn't good... although my dad's 312 knocked like hell, we were sure it needed rebuilding, then I talked him into playing with the timing just for kicks, the knocking stopped.
Have you tried driving it with the vacuum advance line removed and capped? If it does'nt do it then it's pulling in too much vacuum advance. clint
Well dang man. Are you sure that the harmonic balancer has'nt spun making the timing marks be wrong? It spark knocks at a hill with 1/2 throttle or more right? You've backed the timing down to 6 and it keep on doing right? Are you completely sure it's spark knock? Sounds like it is. Any chance it could be the lifters rattling from lack of oil pressure? Sure wish I could help you but I think you've hit the end of my meager amount of knowledge. Don't give up on it, someone will come up with what will probably be something so simple to fix it we'll all slap ourselfs in the forehead. D'oh! clint
This Memorial Day weekend allowed me some time to FINALLY fix the problem I have had, It was the fuel pump making noise!!!! I dont remember who had posted that on here but thanks for the tip it fixed it!! Too bad I have to sell it now
