Gosh Cranky my man, it seems strange for a gashole to be contributing to a Cranky tech thread, but never mind, here goes:
My layout is simlar to Roscoe's, cept that I use an
oil take off sandwich plate with the filter on it. The thermostat is incorporated into that plate. All the parts are Mocal.
I had some severe issues with the
oil passages within that plate -they were very restricted - my die grinder worked overtime on it, both around the take-off ports, and also in and around the thermostat opening passages.
I spoke at length with Mocal about this - they admitted it was an issue, and were supposedly adressing it.
I also ran all the lines in dash 12 (3/4" id equivalent) aeroquip hose and fittings to ensure as low a pressure drop as possible. Some aeroquip (cheaper) fittings are to be avoided - they restrict flow. The non return valve to ensure the Accusump only feeds to the "in" side of the filter is a proper flap valve job, suitable for the line bores I used, and with negligible "forward"
oil pressure drop. It alone ran to $150. SInce it is directly in the oil flow when the thermostat is open, I thought this worthwhile. There are other cheaper alternatives, but they offer far worse restriction to flow.
If you use the thermostat shown above I would recommend you open it up and satisfy yourself that the internal passageways are OK. Especially since you are talking about a road race engine here.
In fact I have issues with a lot of aftermarket oil system equipment - serious engine builders should not view it as "fit and forget", rather as "examine carefully and think about it".
My oiling system works fine on the highways and on the track, so I guess I must have done something right.
HTH