Piston to Valve (PTV) clearance check with clay
| Those of you doing a head and cam swap or building a complete longblock for that matter would be wise to check for piston to valve clearance. It should be REQUIRED as I would never build an engine without testing the clearances and neither should you. It is very easy to make one mistake, and then have a bunch of bent valves as the result. To clay for PTV you simply get some PlayDoh or Silly Putty at the toy store, install a thin 0.1" piece of it over the top of the piston where the valves would contact. Install the heads with an old set of head gaskets, install timing chains like the real build up would have, rotate completely, and measure the thinnest portion of the clay. If its less than 0.030" and the last adjusters are not pumped up with oil you have a serious problem that needs correcting first. It is both a lot easier and CHEAPER to correct before you start the engine than after. |