I don't have any problems with contact. I also doubt if the plate would deflect enuf under normal temps to cause contact. I tried to be reasonable about closing up the clearance to avoid just that scenario.
A mechanical engineer can chime in here... but I'll bet that pump efficiency is VERY sensitive to small changes in gap; max efficiency at very small gaps and efficiency probably decreasing very quickly with small changes, i.e. the pump will probably be useless at a gap greater than .3" or so.
Since the vane tips have higher pressure, and the center hole has lower pressure, it doesn't take much of a gap for the fluid to take the short path around the vanes instead of flowing out to the block. Would be nice to have some hard data......
I'm looking forward to reports from yourselves to confirm or deny my results.
George
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"...out to my ol'55, I pulled away slowly, feeling so holy, god knows i was feeling alive"....written by Tom Wait from the Eagles' Live From The Forum
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