N1 24U Block Oil Galleries Size?

[ToF]

Hi guys,

Does anyone know if the RB26 N1 Blocks have smaller restricted oil galleries?

I've searched around the web and also this forum but can't seem to find any definitive information on this (Maybe I suck at searching?). Wiki page states:

The engine also received improved water and oil channels within the engine block. (http://en.wikipedia.org/wiki/Nissan_RB_engine#RB26DETT_N1)

But this statement does not provide any sources and is pretty vague.

On another forum it was reported that:

Oil curculation to the head is actually reduced in the 24u. Stock rb26 oil gallery orifice is 2mm, n1/24u oil gallery orifice is 1.2mm. This helps to prevent blow by, oil leak from valve guides and insufficient flow to the crank journals. (http://forums.gtrcanada.com/gt-r-tech/19517-24u-n1-block.html)

But following that claim, the person who had the N1 block actually measured the oil gallery from the top of the block at 2mm.

So are the oil galleries really smaller on the N1 block or not? Is it restricted down inside the block but opened up at the top to match all head gaskets?

Any info would be appreciated.

Thanks guys!

[GTRNUR]

I've not noticed any difference at all between the oil galleries in an N1 vs 05u block.

Head flow galleries are the same size as well. The restrictor size is for the most part irrelevant as everyone tend to knock in a 1.1 to 1.5mm restrictor anyway.

[ToF]

I've not noticed any difference at all between the oil galleries in an N1 vs 05u block.

Head flow galleries are the same size as well. The restrictor size is for the most part irrelevant as everyone tend to knock in a 1.1 to 1.5mm restrictor anyway.

Thanks for the reply. Anyone else want to weigh in on it as well?

I understand the restrictor size would be irrelevant if both oil gallaries are the same. If I was to rebuild I would definitely put in restrictors but I'm looking at buying a GTR with an N1 block and the ad doesn't state whether restrictors were used in the build or not. That's the real reason behind my question.

[GTRNUR]

Only the builder can answer that question, unless its a crate N1 motor.