PLATINUM RACING Nissan RB Series Oil gallery restrictor - 0.9mm
Oil issues with the RB Series engines have been well documented, but as always, Platinum has the solution
Platinum has been supplying smaller oil restrictor for the RB26s top end
Extensive R & D over the last 10 years have proven they are a reliable modification, one example is a tested drag car that did prove that during one quarter-mile run an RB can spit out 4L of oil from the rocker covers into the catch can
Furthermore, 90-percent of that accumulative volume waste is a top end that's over-oiled, let alone the oil that actually makes it back to the sump
There is an argument for valve train being cooled, and too much oil does not hurt, but there is sufficient oil in the valve train system, and although too much oil does not hurt the valve train the catch can will fill, and you have less oil in your sump, you only need to lose oil pressure for a split second to detrimentally damage a bottom end.
The only oil source to the top end is a 1x2mm restrictor, up until now commonly replaced by the Tomei 1.55 restrictor, which can still be way too big
Thankfully, Platinum has more proactive 1.5mm, 1.3mm and 1.1mm and now .9mm (we have tested down to .7 with acceptable results thus far)
options available perfectly matched to your set-up.
Also available are blanking plugs to be used in an RB30 given the second hole has to be blocked regardless to meet with an RB25/26 head
Put simply, whether you return to the sump or not, theres too much oil up top on an RB, with way too many band-aid solutions on the market
Fixing the issue itself is key, which is why the widely used Platinum restrictor is a must.
Oil pressure remains constant. Its simply the flow that is restricted, meaning your top end (and wallet) are safe