text: RB30DET Nissan did not produce this engine. It refers to a turbocharged engine using an RB30E short block with the twin-cam head installed from another RB series engine. A common hybrid in Australia and New Zealand (referred to as the RB25/30 or RB26/30) uses an RB30E bottom end mated to a RB25DE, RB25DET or RB26DETT cylinder head and turbo (RB20DE and DET heads are not used as the bores are different in size (RB30  RB20 ); but were originally modified and used on the Tommykaira RB30DE as the RB25 engine did not exist at the time). The RB25DE cylinder head from the A31 Cefiro C33 Laurel or R32 Skyline (aka: Non VCT) can be used. The RB25DET (from the R33 Skyline or C34 Laurel or Stagea) head is also used, however an external oil feed must be fabricated for the variable cam timing (VCT) on the RB25DET, and the oil galleries at the front of the engine are misaligned. The variable cam timing may be disconnected altogether. It may be necessary to reduce the size of the oil restrictors in the block and machine a full face oil pump drive collar onto the crank, (to prevent it shattering at high RPM), with the use of a twin cam oil pump.