Cyborg
valve springs all possess a natural frequency of vibration. it's essential that this does not co incide with that coming from the cam design anywhere within the engines normal operating speed range. In olden days this was not well understood at all, but now it's part of the overall design process, and most usually this frequency clash is arranged to be outside of the engines main operating speed range. If you now add a pushrod into the mix, you really do get problems, for the last thing you ever want it for the natural frequencies of the pushrod and the valve spring(s) to clash. It is all so easy to get into what amounts to a can of worms, and the more one tries to push the limits, the deeper into the can one gets. I've been deep among the worms plenty of times !
Greg
you describe exactly the problem that anyone wishing to seriously boost the performance of a Vincent engine faces. Do you stay within the original outward design envelope, and try to make all modifications within the engine cases, or throw away these concerns and modify as and how necessity determines? Obviously it's for the individual to decide, but Classic Racing rules usually require the outward appearance to be consistent with the original engine, so one ends up being as it were, stuck between a rock and a hard place !
Oexing
your measuring jig appears to have all the essentials for you to obtain meaningfull data.
The value of data to 8 places of decimals is certainly not necessary if only the profile of the cam is the sole interest, but it's when the second and third derivatives are to be investigated that the more detailed data becomes a necessity. The standard for measuring cam data is the Adcole system, very expensive but used throughout industry, and can be tailored to suit each individual users requirements. Almost as good, and certainly far less expensive are Performance Trends Cam Analyser, and Audie Technologies Cam Pro Plus. For either of these you would need their monitor and software program, you have apparently the requisite encoders.
John Andrews also had design software, but since he's been taken over I don't know whether this is still available. He marketed EZcam, a software program designed for measuring and analysis of cam data.
For an understanding of the calculations of the pushrod system, you will find very detailed explanations with all relevant diagrams and mathematics in Jeff Williams previously mentioned book