will putting a block guard in my b16 block allow me to run more boost, i have rods, pistons.... yadah..yadha..yadha, and want to run 18psi, will the cylinder walls take this with the block guard??

 

Your stock sleeves can easily hold this amount of boost. The block gaurd prevent the sleeves from "walking" or shifting under the increased pressure of combustion. When cylinders walk, head gaskets blow. It sucks having to change your head gasket every time you turn up the boost. If you plan on running more boost though, you whould think about just having the block sleeved. Ductile iron sleeves = OEM reliability under high boost applications.

 

Well stated.

 

What about 10 psi? Will block guard work well for that or are sleeves still recommended?

 

You should be fine up to 1 bar.