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Oil spray out of block vent tube

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Hopefully this makes sense and someone may have an answer.


i just rebuilt my l28. Just a re-ring, hone and clean up. The car is converted to carbs so the PCV on the valve cover and the block tube are both vented to air. I finally got the engine running well BUT when I spin her up above about 4500 rpm the block side tube starts puking oil with what seems to be hard carbon deposits. Any idea what would cause this? 


Oil in in the pan is still clean, no leaks anywhere. Oil level isn’t too high. No pressure issues. I don’t see how oil can be running up that high unless I have a blocked passageway elsewhere?



 Engine is running a tad rich but nothing crazy.


let me know what you all think.


thanks in advance!

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You'll have excess blowby during the break in period until the rings seat.  The oil gets thrown by the crankshaft.  Did you remove the internal screen that covers the side port when you had the engine apart?  Might be throwing the oil directly in to the tube.


Since you're not using PCV you could just block that tube.   Then the excess blowby will just come out the hole in the valve cover.


Also, make sure that you didn't overfill with oil.  Too much oil is bad, it will froth and foam.

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The internal screen was not removed. I don’t know why I wasn’t thinking blow by.... engine oil is filled to spec, minus what I have lost making sure the oil spraybar was functioning properly and what has fired out the breather. 


Sounds like ill I’ll just cap it off and leave it at that.


thank you for the input!

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