Tomei Oil Gallery Orifice Nissan RB26DETT

Tomei began operations in 1968 as a race car tuner in Japan. Over the last 40 years Japan has emerged as one of the leaders in automotive research, racing, and culture. Tomei products have been utilized in nearly every motor sport imaginable. Tomei’s racing heritage means their research and design team have first hand knowledge of the extreme demands racing puts on an engine. Using only the highest quality materials means that Tomei’s products can handle the intense strain and heat a purpose built engine will experience whether it be on the street or the track. Tomei’s attention to detail is second to none. All of their products are thoroughly researched and engineered to achieve optimal efficiency. Because of even miniscule differences in measurements can cause catastrophic engine failure, all Tomei products fall within strict tolerances. Tomei machines all of their engine components to enhance airflow and ensure proper fitment and seal.

The Orifice controls the amount of oil flow that is delivered to the head to lubricate the parts in the cylinder head and to cool down the engine assembly. However the stock oil-gallery orifice has a hole that is too large which allows too much oil to be delivered to the cylinder head which will cause various problems such as too much blow-by gas, blowing engine oil, leaking oil through the valve guides, insufficient oil delivery to the crank journal, and allowing air pockets into the system when the oil pan is under horizontal G-Forces. Tomei’s oil gallery orifice was designed from the experience and data they obtained from the development of their N1 endurance and drag racing engines. By restricting the diameter of the orifice to 1.5mm (Normally 2.0mm) Tomei succeeded in securing enough lubrication to the camshaft and valve while maintaining the correct amount of oil in the oil pan, resolving the common lubrication problems. (For added Blow by prevention, we recommend using the TOMEI 3D Profile pistons.)