So I have a B20 block with a B16 head running a small turbo on low boost. Do I need to vent the block (from the back two plugs to a oil catch) or is the breather in the head good enough?

 

you have 2 choices (and no, the breather is NOT good enough!):

1. Vent it through the block like you said to a catch can
2. Weld some bungs on the valve cover and run to a catch can with an oil return line to the oil pan

you are using a block from a motor that normally vents through the head, with a head from a motor that normally vents through the block. see the problem? you need to vent your crankcase pressure somehow or you will blow that thing

 

i got the same problem.

im running a b20 bottom with a b18 head and have been trying to figure out how to vent my crank case. i was about to use the endyn catch can set up and then i started hearing about how bad it is, that it pukes up oil through the top filter. i have heard mixed opinions about running a catch can through the valve cover. but it is necessary to vent the crankcase pressure especially wen in high rpms

 

I already have the plugs for the back of the block, but I could only get one of them out. I seem to have stripped the other one. So I dont think I can get it out until I take it in to get a dyno tune. Should I be ok just running one of them to a catch can and leave the other one blocked for now? I need to get the vtec working before I go in for a tune.

 

bump