Cylinder Head Gaskets Water Jacket Inquiry

[Gregski]

Gentlemen I hope I can explain my question properly as it pertains to the 350 Small Block Chevy (SBC).

How come the water jacket holes in the cylinder heads are so big, yet the gaskets we buy for them have this restricted hole in them the size of a hole punch in your binder paper.

Seems like deliberate / built in restrictions.

Why make the openings in the cast iron so big, if you are going to restrict them with a gasket?

[Gregski]

Same goes for the engine block, the block has three holes the size I could put my thumb through, yet the holes in the gasket are only big enough for my pinky.

[burban nate]

I would guess that the holes only need to be as big as the gasket for proper operation. However, the holes in block and heads needed to be big enough for the sand cores to be extracted after they were cast.

Nate

[Blessed66]

I was gonna say restriction.

Part of what helps water and antifreeze keep these engines cool is the water being there long enough for it to pull heat from the cylinders (or other hot things). If it flowed freely, it wouldn't leech heat away from the engine like it's suppossed to.