Turn & Burn
Club Member
I’m currently stripping and modifying my N42 block ready for reboring, perf cam etc. In the Honsowetz book ‘How Tune your Nissan engine’ it talks about opening up the restriction orifice in the top of the block from 2mm to 3mm to increase flow to the cam, especially relevant with a high lift cam without a spray bar fitted. The orifice is located centrally in the rh side of the block top. There is a photo and a diagram that show this.
My block has two orifices fitted, as shown in the photo (washers placed on them for clarity), and this second orifice is not mentioned. As far as I can tell this leads to the cam carriers, so I already have twice the flow to the cam.
I assume others have come across this 2nd orifice? Have u opened them both up or left as is? I can’t find any mention on the internet. Just for info I have a turbo oil pump for the new build.
Cheers
My block has two orifices fitted, as shown in the photo (washers placed on them for clarity), and this second orifice is not mentioned. As far as I can tell this leads to the cam carriers, so I already have twice the flow to the cam.
I assume others have come across this 2nd orifice? Have u opened them both up or left as is? I can’t find any mention on the internet. Just for info I have a turbo oil pump for the new build.
Cheers