Valve cover breather leaker tinker

Hello fellow Mazda enthusiast, I recently rebuilt my 2.2 motor bored over .40 w/ a pacesetter and a Weber carb.
I have a breather filter attached to the valve cover but she seems to leak oil (kinda bubbles out after a short drive @ freeway speeds?). My question is 1. I have seen a picture or two where some members have simply capped off this orifice. What are be the repercussions if this is done? 2. How do I fix this oil leak issue if this breather needs to be in place?

I've done some research and it seems as if this is an issue people have put with...my oil has gone down so much in the 6-8 miles that I had to add oil.....it just seems excessive....

lil help please....

thanks for your 2

Purchased an oil catch can from ebay. thanks for looking.

dont think thats right, you should only be getting a small bit of oil out of it, do you know if the splash cap is still on the inside?

Yes, the splash deal is in place. Wtf?

Does seem odd to be getting that much oil out of the valve cover breather. I believe the main purpose for the breather is to let IN some air to the crank case and the PCV valve is there to make sure the crankcase is NOT pressurized by exhaust gases. Which leads me to ask is the PCV valve working correctly?

Yes, I initially thought the pcv was the underlying issue, so I just replaced i it ($3dollar cheap insurance) along with the hose.

Anyone else?

engine blow by. When exhaust gets past the piston rings, the excesive crankcase pressure pushes oil out the breather. Did you make sure your ring gaps were staggered during the rebuild?

I remember staggering the rings during the build. I have read about performing a compression test. does anyone know what would be the right numbers with a .40 over and 86mm bore? Also, what would be the acceptable oil pressure?

thanks guys...

With or without the .40 over the compression numbers should be 120psi or better. More importantly is all 4 readings should be within 5% (i.e. cylinder 1=121psi, cylinder 2=123psi, cylinder 3=120psi, cylinder 4=122 psi). Typically when I do a compression test I remove all 4 spark plugs and open the throttle wide open.

As for the oil pressure a good rule of thumb is you should have at least 10# of pressure per 1,000 rpm. At idle you really should be able to maintain 15#. On the highway you should see around 40psi.