The D while in the engine code stands for dual overhead camshaft (DOHC). This can be accomplished by fitting an RB25DE or RB26DETT cylinder head and or turbo to a normal RB30E/T block. The RB25DET isn't ordinarily used.is a strong engine, powering more than 3 generations with the Skyline GT-R. The famous RB26DETT is respected across the globe for i