Valve hitting a piston

[stevesLX]

So how can I tell whether or not I have valves hitting my pistons? I have been told that its possible that's my noise and not lifters. I dont see how ecspecially since I had the car up to 120MPH yesterday and the car minus the sound runs like a champ. I had the covers off again last night after driving it and once again I cant move my rockers side to side or up and down so I dont think I have any lifters collapsed or collapsing. I started it back up with the cover off and it sounds like the tapping is up top right there. I checked both with the valve open and closed to see if the rockers were tapping the retainer or spring and its not. So who knows. So how exactly can you find out if the valves are hitting the pistons?

 

[stangjunkie]

put playdough on the piston and crank the motor by hand then pop head off and examine.
or place head on motor without gasket turn over by hand and see if head rises of block.

ever heard of google??

 

[stevesLX]

O.K. how much playdoh do I use? How thin or how thick am I suppose to make it?

 

[GT_Rich]

There's a method for checking P to V clearance with the heads still on the car. Do a search and save yourself a head gasket. I've used the playdoh method, but it was a check during assembly. Did you check clearance before using an F-cam?

 

[85_SS_302_Coupe]

The F303 is only a .512 lift cam, you shouldn't be having PTV clearance issues unless you've had your heads milled down or you've got an '86 short block or some other pistons that don't have much valve relief...unless you're running 1.7 rockers or something.