Lynn,
Thanks for all the oil pump, inlet tube etc. information.  My engine is
a stock RX-8 engine pulled out of a wreck with about 9500 miles.  The
pan and oil pick-up are stock with a 1/2 inch spacer on the oil
pick-up.  The crankshaft oil bypass has been disabled and the oil
pick-up is the stock plastic item.  From the information you sent it
appears I could really improve my oil pick-up system!  On start-up my
oil goes to 85 psi.  After warm-up it is slightly slower.  On take-off
it goes to 85 but as the oil temp exceeds 200 the oil pressure comes
down some.  I will open the filter and check it when I change to Redline
straight 40 W racing oil.  I compared the oil dip stick from a 1997 13 B
and the Renesis.  It looks like the oil level in the Renesis is about 1
1/2 inch lower in the Renesis.

I have never seen the Renesis apart, and have no data about their pickups. I would hope that they fixed everything, but I am often disappointed.

 

The 85 pounds you see at first, is being controlled by the relief valve. So, normal oil pressure is 85 pounds. It may be less than that at idle, where pump output is at it's lowest.

 

Lower pressure at RPM, indicates much thinning from over heated oil, and oil foaming. So the pump looks to be in good shape. If, before the oil gets to full temperature, you can still get 85 PSI, then the pickup must be close to adequate.

 

Racing Beat says 210 degrees is the very highest oil temp allowed. I have been to 200 degrees on a real hot day but never more than that. Oil in the wedge is much hotter than the sump oil temps. So even 200 makes me buy more coolers.

 

Racing Beat says oil foaming can take off as much as 10 PSI. So there is another cause at work as well.

 

Getting the water temp down to 180 tops will help a bunch.

 

Lynn E. Hanover