Low oil pressure 3300 engine with solid lifters
My friend has an old 3300 engine with solid lifters (year 2000 mod.)engine has 1000 hour and we have changed the conrod bearings. When we started the engine after overhaul we experience low oil pressure. 1,8 Bar on 2750 rpm and 0,2 bar on 850 rpm. The reason for changing the bearing was low oil pressure on idle speed 0,5 bar on 850. We have changed the o-ring behind the oil pump base plate and applied loctite 518 we have also checked the suction pipe to oil sump are fixed and no play. We have checked the pressure relief valve are clean and sealing propper to seat. We have tried different oil pumps all with same result. We are running out of options, any idea?
It would be worth getting a different oil pressure gauge or sender and making sure that the reading is accurate... You also mentioned that you've tried different oil pumps - I assume you're using the bigger, 3300 pump and that it's within the wear limits in the overhaul manual? Finally, did the pressure change at all when you adjusted the relief valve?