I have a high compression 13.5 gsr does not smoke runs good tune on e85 but if I go beat on it one good time or ever so often its okay but if I turn around and do it again the second time it will spray oil out of the breather on my catch can I have one line from the back of the block to the catch can and the other comes from a vibrant oil cap breather. Did a compression test and its 280 across the board but have not done a leak down test

if I take the oil cap off while The motor running it has some crankcase pressure but is not smoking Out of the oil cap just clear air with a little oil splash

 

Did you use the plug on the back of the block near the oil pressure sensor (timing belt side) ? If so, that could be the reason why. I had the same problem and i have heard other people recommend not to use it. So a quick fix for me was to turn the catchtank upside down (lol) so the oil can go back the way it came from instead of filling up the tank and make a mess in the enginebay. But now i use a return hose to the oil sump and i use both plugs on the back. (an10)

 

The block plugs are notorious for pushing too much oil into the can. A large capacity can with a drain back does work. But I prefer to keep the oil in the engine. One or two -10 AN on the front of the valve cover works a lot better.

 

absolutely spot on!

i used to have to empty my can every 2 passes when vented from the block. i swapped to 2 -10 off the valve cover and i can make 3 passes without coming close to emptying it at all

 

Yep, sadly the valve cover fittings add clutter in direct view but its very effective. The ports on the back of the block have large amounts of oil drainback from the head, moving crankcase pressure through that path creates issues.

 

If the catch can is too small then you will get blow back from the ports in the back. but if you are running atleast 2 valve cover ports and the lines to back of the block for drain back and for the air to flow thru it should equalize and flow nicely. locash makes a really nice kit with the cnc an fitting plugs for the back.
http://www.locashdyno.com/store2/ind...roducts_id=297

 

thanks for all the help Itook the other plug out of the back of the block and put a fitting in the valve cover behind the baffling and now I have no issues