Welcome to the Nissan Patrol forum. To post a question and to see less adds on the forum then you will have to register
first. We are an easy going friendly forum so join in the conversations and feel free to ask any questions.
Become a forum sponsor for only $20 and see no adds with faster page loading times and many extras benefits.
hi all ive been searching around and cant find any info on this one. im putting a new head on my tb42 and i noticed that the water journals on inlet side of the old and new gaskets are much smaller than the journals in head and block while the exhaust side holes in the gasket are fully opened up to the size of journals in block and head. any ideas why this is? and should it be or should i open the holes up to the size of the journals in block and head? i thought maybe its to increase flow on the hot side of the head, but wouldnt max flow all around be better? IMG_1397.JPG
you can see some of the holes are completetly closed on the old gasket. surely this is not right. the block and head have matching journals shouldnt the gasket match those?
any thoughts or previous experience would be greatly apreciated
From what I've heard, the coolant passages are made that way to make the water flow a specific way through the head. I recently had the head off my tb42 and thought exactly the same thing as you. I opened up the water passages on the head gasket, not really knowing why they were sized the way they were. But the engine runs the same temp as before and I haven't noticed any adverse effects so all good.
cheers for the info Parksy
After looking at it the new gasket and thinking about it for a while i might just leave the gasket as it comes as it appears it pushing water to the back and the exhaust side progressively to increase the pressure and flow further away from the water pump. its a bit of an odd way to do it rather than just designing the journals to naturally flow even pressure across the head.