I just replaced the head gasket on a 1989 CRX HF. There's a small aluminum orifice piece that sits in the top of the block. What is it for? What will happen if I run the engine without it?

 

if you run the engine with out it
you will run the engine with no oil pressure
and all your bearings will become bad bearings in a matter of about one minute

what this little peace does is it keeps oil pressure in the block and limits the amount of oil going up top

im talking about the peace circled in red



if you forgot to put this back in
sadly you have to remove everything again
and install it