Spockwerks;
Quote:
"On another note, you can easily force twice as much oil through any orifice of given size, it shows up as higher pressure at a higher flow rate."
What you're saying is only true, if the orifice was originally designed to allow the 100% extra flowrate. Yamaha designed the oil system (oil galleries/oil orifices) on the XS650 to match up with the stock oil pump flowrate, not a pump that can pump twice the stock flowrate.
There is something called the System Curve, when dealing with pumps, that pump a liquid through a system of piping or orifices. Because an orifice has a fixed amount of resistance to flow, the actual flowrate must follow the System Curve.
The next 2 paragraghs, and Fig 6 picture, are taken from a pump manufacturer's web site. They are talking about running 2 equal pumps in parallel, which is the same as doubling the flow capacity of a single pump. This is a good example of what happens when its assumed that doubling pumping capacity, will double the flowrate. The S curve for the XS650 will be more "steep" than "flat", and therefore I suspect the Mikesxs HP pump may increase flowrate by 15% to 20%, certainly not 100%.
Flat system curves
When the system resistance is relatively flat (not much friction), operating additional pumps in parallel will produce a useful flow increase. Incorrectly, many operators expect that flow will double if two pumps are running in parallel. This cannot happen because, when added together, the combined pump curve intersects the system curve at a higher head due to increased frictional resistance and hence each pump will be operating at a higher head and lower individual flow than when operating alone.
Steep system curves
Refer Fig 6.
When the system curve is steep (mostly friction) this steep increase in friction head as system flow increases, means that each pump will be running at a significantly higher head and the individual pump flows will be much less than in single operation. Overall, the change in flow will be small when additional pumps are switched on.