I found a car with a 15L engine and I am planning to build a racer/speedster because only the mechanical part is worthwhile. I am looking for information on the camshaft/tappets specifications and valve overlap. I found that the tappets do not have a plane surface at the bottom, that surprised me. The only related information that I found is the Valve Timing Diagram in Fig 39 in the Repair Manual, Four Cylinder Models (1929). In this diagram the is not valve overlap and most probably in the 15L is similar. I would like to find information for the 14L/15L engine and try to see if by modifying the curve in the tappets surface I can manage the valve opening time and overlap. Thanks in advance

Where Are You From? Argentina

Do You own a car built by Durant? yes, D65