The Nitto RB Oil Gallery Restrictor and Block-Off Kit is a simple yet highly effective modification for controlling oil flow and pressure within Nissan RB-series engines. Proper oil management is critical in high-performance RB builds, especially when using upgraded oil pumps and operating at sustained high RPM.
Nitto oil gallery restrictors are precision-machined components designed to regulate the volume of oil supplied to the cylinder head, helping prevent excessive oil accumulation in the valvetrain area. By limiting unnecessary oil flow to the head, this modification helps maintain proper oil pressure at the crankshaft and rod bearings—where it is needed most.
This upgrade is widely considered one of the most cost-effective reliability improvements for RB engines, particularly in engines equipped with high-flow oil pumps or built for motorsport use.
RB Oil Gallery Restrictor & Block-Off Guide
Note:
These sizing recommendations are general guidelines and may vary depending on engine build specifications, oil pump selection, and intended engine usage.
Nitto oil gallery restrictors are used to control oil flow and pressure, reducing the risk of oil pooling in the cylinder head that can occur with high-volume oil pumps and high-RPM operation.
RB26 Applications
RB26 with Tomei or Nitto Oil Pump
• 1.1mm Front Feed Restrictor
• Rear Feed Block-Off
RB26 with N1 Pump (Upgraded Internals)
• 1.3mm Front Feed Restrictor
• Rear Feed Block-Off
RB20 / RB25 Applications
RB20 / RB25 with Nitto or Tomei Oil Pump
• 1.3mm Front Feed Restrictor
• Rear Feed Block-Off
RB20 / RB25 with N1 Pump (Upgraded Internals)
• 1.3mm Front Feed Restrictor
• Rear Feed Block-Off
RB25 Neo Applications
RB25 Neo with Nitto or Tomei Oil Pump
• Open VVT Feed
• 1.3mm Front Feed Restrictor
• Rear Feed Block-Off
RB25 Neo with N1 Pump (Upgraded Internals)
• Open VVT Feed
• 1.3mm Front Feed Restrictor
• Rear Feed Block-Off
RB26 Head / RB25 Block Hybrid Applications
Nitto oil gallery block-offs are also used when installing an RB26 or Neo cylinder head onto an RB25 block. Because RB26 and Neo heads utilize a solid lifter design, the RB25 VCT oil gallery must be blocked off to ensure proper oil system function.
- Trim:
- GT-R
- Trim:
- Non GT-R
