Hi All, just wondering if there is any reason why i shouldn't drill extra holes through the head gasket where some of the coolant galleries are blocked by the gasket or only have very small holes punched? Seems restrictive and the holes could be made bigger to allow more coolant flow through from the heads to the block. Any problems with this?
Do not modify the head gasket, the holes are sized and placed to allow coolant to flow to the desired parts of the engine at the correct flow rates. Some say you can drill the gasket and cylinder heads at the front and rear where the block has a coolant gallery but nissan did not do this for some reason and I am sure they invested alot of time and money into getting it to work properly as is.
UAS seem to be the only people doing this mod. You may be limiting flow through the turbos if you do this.
yeah Thanks guys! I had this idea after looking at the old head gasket but i pulled out the new head gasket after writing this and noticed that the holes were a bit bigger and besides that it is a commetic gasket and there was no way i'd consider modifying that. Cheers for the info anyway guys :thumbup: Next question though.... does it matter at all whether i install the cams etc on the heeads before i bolt them to the block or better to do this after? i don't think it really matters either way as long as i make sure the pistons are at TDC. But if anyone has an opinion on the easiest / best way then i'm happy to hear it
I find that you say that interesting. Just wondering if you have any thoughts on why it is that cylinders 5 and 6 are usually the first to fail? I'd thought it was because they ran hotter due to being the last in the fuel rail and not getting enough cooling due to the blind coolant galleries (which I understood to be a casting residue defect). I dont have an opinion either way, just curious..
I have also read that 5 and 6 are the first to go with lower compression as the a/f is higher than cylinders 1,2,3,4. Due to the design of the plenum as the air is kinda rammed down to the back, if that makes sense
