Quote Originally Posted by gsimpson View Post
I was reading the article and why would you make the holes in the head gasket so much smaller than the passages in the block and head?

Also wouldn't make the engine run cooler with increased head gasket passages?

Wouldn't you drill them out to match the ports in the block and heads?
There are a lot of engineering principles involved with coolant flow and heat transfer. The various holes in the head gaskets are sized to allow a prescribed amount of coolant flow. The size of the coolant passages in the head/block are the size they are for at least a couple of different reasons.... 1- Manufacturing ease and core cleanout. 2- To control coolant flow.

This is why the article was written.... Wannabe vendors just can't decide on their own to change coolant flow without some sort of dynamic testing on a fully instrumented engine to measure the effects of any change. The vendor data should also be published so it can be verified.