i just finished rebuilding my 76 w/302 and i seem to have a problem called valve overlap. a mechanic told me this.almsot as soon as my intake valve closes the exaust valve starts to open. is anyone here familiar with this problem and does anyone know of a solution???any advice will help. thanks ladies and gents..sparky

Camshafts are all designed with a certain amount of degrees of valve overlap.

yes i understand that to be true but there has to be a problem if one valve is barely closed when the next one starts to open.this would mean that during the compression stroke the intake valve would still be closing resulting in no compression or the exaust valve is opening causing the same problem of no compression right??

Hi. <br> You have it backwards. Your ex valve is closing when your intake valve is starting to open. This is actually a good thing, it creates a vacuum of sorts and helps to pull air and fuel into the cylinder. Is your problem iwth no compression or what? Hope this helps to understand overlap. <br><br>Paul

If the valves are staying open TOO long,then you have a problems.Someone cranked a rocker down too tight,a valve is bent,a spring is weak,carbon or some physical piece is stuck under a valve head,a valve is burnt and cracked open,a lifter is pumped way up and wont "bleed" down......many possibilities.