Hello Got some major headache here I've rebuilt an rb26 after oil-pump failure But when i start it up with 10-40w oil (20'c oiltemp) i got oil pressure of 2.5bar/1200rpm that drops to 1.5bar/1200rpm after 2mins. After 2mins i tried 3000rpm = 3bar This seems way to low for me. I've measured the pressure with a mechanical and one electrical gauge, not the dash-gauge. I've done the rebuild myself (lot of expereince with 4g63, non with rb26) Oil pump is a good used condition stock case with NEW reimax gears. Main bearing clearences is 0.07mm Rod bearings cleaences is 0.07mm Oil squirters is torqued to spec. Tomei 1.5mm oil restrickor to head. Grex/Trust oil filter relocation and oil cooler kit (hoses connected the right way) Crank is a R33 with good oil pump drive (modded to 0.2mm clearance) I don't really know what it can be