Oil puking out the breather

[n9rracing]

Hey guys need some suggestions. Ran our season opener last night and we started puking oil out the breather real heavy. I figured we broke the top of the piston. We took the head off this morning and the pistons look good. We have been running this combo for three years. All we did this winter is roll some bearing in it with no other changes other than gaskets. Other than a broke piston what would cause this. Just getting some opinions before we pull the motor the rest the way apart.

[Milford Motorsports]

I would check the rings,sounds like you may a few that are broken or not sealing properly.Did you pull the pistons when you changed the bearings?Only other cause would be if the crankcase vent is blocked.These engines were designed from the factory to vent from the block not the valve cover.Too much oil flows from the cam to allow venting only from the top.

[supertruck57]

do you by chance run a crankcase breather? we ran one and everytime i would let off the gas at high rpm entering corner the pressure had nowhere to go cause the valve would close and pushed oil out the valve cover breather. unhooked it havent had problem since

[n9rracing]

No we didn't pull the pistons when we changed the bearings. The compression was good and the cylinder walls looked great so we didn't touch them. As far as the vent I run a braided #10 hose to the breather tube on top of the valve cover. I've been running it that way for years with no issues. I don't know if the case vent is blocked yet cause I havnt takin the pan off yet. I'm thinking that the piston might be broke between the rings. I'll find out tonight. Thanks for the input

[n9rracing]

Well we pulled the motor the rest of the way apart last night and we find anything wrong with the pistons or the rings. Cylinder walls look good and there wasn't anything wrong with the crankcase breather area. I'm out of ideas. Need your guys advise.

[supertruck57]

My dad said if everything internally is fine, then your crankcase breather itself can be plugged up. A spider from over winter time could of made a Web or something make a nest and clog it.

[dannyracer6]

Is the block breather hole baffel still in place. It has to bein there or you will puke oil.

Dan