Good points, Claude.
With the Mystic non thermostat cover I'm seeing an outlet and inlet. I was thinking the oil must flow through the Mystic radiator all the time?
I was
thinking that without a filter element in the oil filter cavity, oil would flow straight out the 'out hole' in the cover, through the remote filter and then back through the 'in hole' in the cover, which joins/seals? up with the long tube in the centre of the oil filter cavity, and onwards through the gallery.
Does the mystic cover even work like that??
I think I could also do it with the thermostat, without a filter element. But it depends how good the seal is between the thermostat, and the centre tube. If it seals well, I think the thermostat housing could take the full flow of oil. The white o ring and shim would still be used.The thermostat 'piston or valve' would need to be permanently pushed into the fully open position by a long bolt, which is what I do in summer anyway.
I think it could be done with the piston removed actually.
All comes down to a good seal between the thermostat housing and the long tube, and if there was a leak at that point it would pass unfiltered oil from the cavity into the tube and on through the gallery.
My RS long tube has notches in the end, maybe that's the bleed off so the cooler doesn't get all the flow. If thats the case, I'd need a tube without notches to fully seal with the cover.
In my imagination, anyway.
Maybe I could use similar to the Z89A from the Chrysler 4 litre six. Not toooo big and handles molasses.