Is this RB Head Gasket cooling mod OK?

[TurboX]

On my RB20DET new standard head gasket from Nissan there are the circular holes through the gasket where the water jackets come through the block to the head.

But these Block/Head water jacket holes are semicircular and at least 4 times the area of the single round hole in the gasket.

This is probably OK for a standard RB but I am looking for 200+ AWkW!

I am inclined to cut the holes in the gasket to the same size as the jacket holes for more flow on my fairly well modded RB20 to improve cooling flow.

Anyone got any advice on this mod?

[SteveL]

Be careful....I've noticed that with genuine RB30 head gaskets (and I think RB25...have to check) the holes vary in size from front to back - bigger at the back, smaller at the front. I think the idea is to promote even coolant flow in the block. It's possible by just opening them all up you could end up with hot spots, particularly at the back of the block. RB20's could be different, but check to be sure.

[sweetr33]

i wouldnt tamper with a genuine headgasket, i would leave it the way it is. the cooling system will doa fine job. upgrade to a gtr waterpump, i would imagin they bolt up to the rb20!!