Whats the differance between a closed deck block and a semi closed deck block?
I have a 93 wrx which as far as I know has a closed deck block is this better than a semi closed block?

cheers Paul

 

something to do with better head gasket sealing. wouldnt know which one is what though

stew

 

a closed deck block has more material around the cylinder walls so theoretically it will be stronger. However people on here are running over 400bhp with the semi closed block. If you do a search you will find some pictures and it will become clear