Dat klepje sluit de normale olietoevoer-route naar het filter af, want bij de Speedster gaat die eerst via de slang richting de oliekoeler.
Even wat meer "copy-paste" uitleg over de Z22SE oil flow:
Oil goes up the oil pick up pipe, through the lower block craddle, into the oil pump, out of the pump to the side of the engine
(it would normally go to the oil filter but this route is blocked off on the vx220/Speedster), through the hose, into the oil cooler, out of the cooler into the oil filter, out of the oil filter into the main oil galleries of the block and also through a restrictor into the head.
inside the block it feeds the rear bearings of the balancer shafts, the main bearings, the big end bearings, the front balancer shaft bearings, the balancer shaft chain tensioner and the oil jet
the head oilways feed the main chain tensioner, auxillary drive (blanked off on the vx220), cam bearings and hydraulic lifters