Piston Crown Valve Pockets
All of the two-valve or four-valve cylinder head design programs within this software suite (4-Valve Head Layout, 2-Valve Head Layout and Side Valve Head Layout) calculate either any valve clashing, or any valve head intrusion into a piston crown, during the valve overlap period.
Those programs compute the depth and location of this valve head intrusion but only in terms of a valve head with the dimensions of its valve seat and only with valves which are angled with respect to the roof angle of the relevant combustion chamber but only with the valve orientation as parallel with the cylinder axis.
This program complements all of those programs but permits the input of the geometry of the size and location of the actual valve head within the cylinder and which also can be simultaneously canted with respect to the cylinder axis and at right angles to it.
The intrusion of a valve, which has known actual head geometry, from a location in three dimensions above and into a moving piston crown can now be computed with accuracy.
The program permits the dimensioning of a machining cutter to manufacture this valve pocket with specified side and axial clearances over the intrusion created by the valve head and to provide the orientation and location of this cutter for the manufacturing process.
The program also gives an output of an amended valve lift profile which would not require a pocket to be machined in the piston crown, the so-called 'piston-chasing' valve lift profile, and this output is automatically formatted so that it can be immediately fed back to the '4stHEAD valve lift design' programs for an attempt to be made to precisely design-in that feature.
Many of the pictures which illustrate this program here on the website are culled directly from the on-line help files of the software. The symbols on the sketches directly correspond to those of the input and output data values that you see on the screen snapshot, also shown here, of the main working input/output/control page. Like so many of the programs in this suite, the computation is conducted dynamically and graphically on the screen so that the user can actually observe the valve head intrusion and the piston motion but in all three dimensions simultaneously.
©Prof Blair & Associates