The oil pump is the engines heart. Oil is its blood.  Carrying good stuff to all the parts in the engine, taking bad stuff away.  If the heart fails, the engine fails.  In the case of an RB26, when something goes wrong, you normally have a rod exit the block. When that happens, you end up with a lot of scrap metal. To avoid large, expensive pieces of scrap metal, you should read though a few of the items I have posted below.  
  • Oil pump
  • Oil restrictor
  • Oil pan baffle plates
  • Oil pan modifications
  • Oil pickups
  • Oil drain back
  • Accusump
  • Cam Cover
  • Dry Sump - Street car 
 

Oil pump

A cool fact about the oil pump, its not generally possible to replace in the car due to the oil pump relief valve being in the way. Also to get the oil pan off, you need to drop the subframe. When you drop the subframe, nothing supports the engine. Its a much easier job to take the motor out. A few people have changed them in the car. I have changed them in the car, but after the rig supporting the motor slipped one time, I will never do that again. 450 lbs of motor crashing down on my head is not how I want to die.
  • Stock
  • N1
  • Nismo
  • JUN
  • Broken Jun gear at the flat
    •  
  • Greddy
  • HKS
  • Reinik
  • Tomei
  • Dry Sump

YouTube Video

Oil pump drive

There is an early and a late oil pump drive.  The early drive only very minimally engages the flats on the oil pump gear to drive it.  You can see when Nissan went to the later style pump that the width and engagement about doubled. If you have an early crank, you should think about swapping the crank out for a later crank, or purchasing a crank collar.
Early oil pump drive
Early drive- Notice how much smaller it is than the late drive. Also notice the small shiny spot. That area is the only part that actually engages the pump. 
Late oil pump drive
Late drive - Notice the wear on the flat spot. Compare the width here to the early drive shown below.

YouTube Video

Oil restrictor

Located in block. Limits the amount of oil that flows to the head. As the RB26 is solid lifter, it does not need as much oil up in the head as a hydraulic lifter RB25. Stock 2.0mm N1 1.2 mm Tomei 1.5 mm

Swinging oil pickup

  • Special Nismo part
  • Was used in the Super Taikyu spec motors

    Oil pan baffle plates and modifications

    Stock RB26 oil pan. Front differential is on the right side.

     

    Tomei baffle plate

    Extension on left side of the pan.
    Extended sump on Australian GT-R

    Oil Drainback

    Some people modify their RB26 to return oil that accumulates at the back of the head directly back to the oil pan. Some will return to the oil drain, others to other places on the engine.

    Accusump

    .
    The Accusump is an oil accumulator that stores a reserve of oil under pressure. Under conditions of a drop in oil pressure, the oil that is in the Accusump pressurizes the oiling system. Once the oil pressure comes back up, the Accusump fills back up

    Cam Cover

    The cam covers, or valve covers in an RB26 have breathers at the back of the engine.  An RB26 moves a lot of aerated oil around in the engine and though the top of the engine. An oil catch can, and baffled breathers are important to prevent oil contaminating the intake air. Stock valve cover baffling at the top. Nismo N1 baffling at the bottom.

    Dry Sump

    Dry sump on a street car R32 GT-R
    Dry sump pump