Post by peterl78940 on Jul 17, 2010 0:07:10 GMT -5
does anyone know how to interpret the "VALVE DIAGRAM" on page 101.
where do the dimensions "0.134-R Travel Circle",
and the "0.055-R Lap Circle" come from,
I have found that 0.055" is the "overlap", the amount the valve has to slide before the intake begins to open, by studying the dimensions of the valve slider and the dimensions of the ports on the top of the cylinder,
and that 0.134" is approximately the half-travel of the valve slider in full-gear, in other words { 0.078 port width + 0.055 valve overlap + 0.001 overtravel } => 0.134, with the minor glitch that the overtravel is supposed to be in the range .004 ~ .008
given those two inputs, and evidently the "travel circle" and the "lap circle" are concentric with center of the diagram, what else is input information, and then how is the diagram constructed, and finally what is output information...?...
what are the clear portions of the circles, what are the shaded portions of the circles, what defines the arc in the lower circle, its radius is not given anywhere...
I am now guessing that this diagram does not show the effect of changing the "gear", since one of its primary inputs is the valve travel in "full-gear", and an entirely new diagram would have to be drawn for an "intermediate-gear" position of the gear lever...
I was expecting this diagram to somehow relate to the Walshaerts mechanism connecting to the cross-slide via the combination lever...?...
any information would be appreciated, as I did a google search a couple years ago and only found qualitative not quantitative descriptions of "lap" etc... (in fact, most of the descriptions and definitions I found were downright confusing by using more jargon to define the jargon they were trying to explain).
if someone knows of some website that has a clear explanation for this type of diagram that would be great, so far I have not even seen another copy of this diagram anywhere on the internet...
many thanks in advance,
Pete Lawrence.