Ok, so my catch can setup is an odd one. Its a B&R drainback kit, this one,



I modified the top port to a -10 and have it routed to the slash cut in my exhaust, right around the oil pan.

so it drains to the block on the bottom, and vaccum's from the top, baffle in the middle.

Well anyway, it totally works, I can see white blowby spewing from my exhaust when I get on it.

I have a 4" e-cut right off the downpipe, so when I open it all the exhaust is bypassing the slash cut (i would assume no exhaust would go out the back)

The slash cut has a check-valve attached to it, (so exhaust cant go up)

so my question is, while the e-cut is open, would the blowby have enough pressure to push past the checkvalve? so the blowby can actually exit? I dont see any white smoke while e-cut it open. Would it be fine if I removed the check-valve so I know atleast the blowby is getting out.

I tried attaching and removing the slashcut during a dyno session, and it didnt make any hp difference.

 

the check valves arent that strong glove it should be fine. but if i was you i would make it easier for the block to breathe when the e-cut is open