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Hey my mate recently blew up his R33 engine. Noting the basics its a Rb25 block, GTR crank, GTR rods and 92mm pistons. Anyhow when he took the pistons out there was a cutout up the side of the piston and when u look down the cylinder bore from the top where the head would normally sit there is a squirter nozzle there which appears to squirt oil onto the underside of the piston. My question being, is this a standard item on RB engines? We havent seen inside one b4 so wouldnt have a clue. The cutout in the piston is on the same side as the oil squirter like its been cut out to clear the nozzle? Anyone got ideas?

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yes as said b4 they are std in most nissan engines due too japan having the knowledge that you cant get enuff lubrication .....

the oil squirters are for bore lubrication on the thrust side due too the high friction point of the bore just too add an increase of less friction ...if you know what i mean ...

i was glad that my engine had them due too my after market rods having no oil squirter through the centre of the rod so the oil squirters will do the work ....

hope i was of help ...

  • 3 weeks later...

The oil squirters are for piston crown cooling. The rod squirters are for bore lubrication. It is interesting that many aftermarket forged rods dont bother with the bore lubrication holes, not even cut outs on the thrust face of the big end, as some other manufacturers do. Argo are one such company I've enquired about this. They said they have never had any failures attributable to no bore lubrication. Obviously the cloud of oil mist in the sump normally must provide adequate lubrication for this, although it then raises the issue as to why OEM manufacturers bother with it.

hehe i do get you mate, but the angle of my oil squirters do not meet the angle too the piston ..... im saying that oil squirters may also be there for a dual perpose too also lubricate the bore as well my squirters are not on a 90 degree angle but about 35 degree there for when the piston is at top dead center it would lubric8 the bore then when piston comes down near bottom dead center they would cool the piston crown...... get me ....

im not in for a debate im just telling you that not all squirters are the same,

im not just a young enthusiest mate im an engineer as well .

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