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First, what ever you push in to the valve covers can't be touching the baffles. Gotta correct that first. Second, if you are racing with a full exhaust ( like you street drive it), the exhaust evac system won't work. Any back pressure on the evac tubes will close off the valves and shut the system off. If you are running a pcv, the crankcase ( other valve cover ) has to be vented to the atmosphere. Having a pcv on one valve cover and an exhaust evac on the other won't work as there will be no vent to the atmosphere that way. Keep in mind all these scenerios can change a little bit based on exhaust back pressure and how much engine blow-by you have. Example: When I test on the street, I run a very minimal back pressure exhaust system. With my exhaust evac system hooked up ( both sides ) I can still pull a small amount of vacuum at idle and up to about 2K ( around 3" of water ). Somewhere around 2500rpm the exhaust back pressure is enough to close off the valves and the crankcase goes to pressure. If I wind it up, it will be enough pressure to blow out a breather so the crankcase can vent. So, if you are running a full exhaust ( quiet enough to be legal ), exhaust evacs won't work. They will work great if you run open headers at the track. If you don't want to play switcharu between the street and the track, just run 2 breathers and vent them to the atmosphere - after you fix the breather to baffle problem. Be prepared to wipe down your fire wall on a regular interval.




I agree with you about the breathers touching the valve cover baffles not being right....Not sure if I should just cut the breather nipple that goes in to the valve cover, or modify the valve cover baffles in some fashion.

I don't think my issue was the valve closing from backpressure- if it was, how was oil getting past the check valve and burning out the passenger side tail pipe where I had the evac tube? Also, my evac hose had quite a lot of oil in it.

I figured that with the pcv hooked up that the other breather going to the evac would be like venting to the atmosphere...I guess I was wrong lol...and when I put a breather in the driver side valve cover, I have the same issue of seeping just not as bad as the passenger side.

I run a full exhaust at the track as I do on the street, with bullet mufflers, and I plan to continue to run it that way as my class requires mufflers.

Thanks for the insight and suggestions so far! I will try to modify my breathers first and see what happens.


Yes, you can cut back the breather nipples 1/8" or there abouts and still have enough "bump" to hold them in. I did that for clearance on my baffles. If you are running a full exhaust, dump the exhaust evac system. It aint gonna work. It sounds like you have excessive blow-by. I run lots of ring clearance on my blown application, but don't have oil in my exhaust evac hoses? It might be time to do a compression test and leak down test to get an idea of engine health. How do the plugs look? Got oil consumption issues? If you are not running a locking dip stick, does it stay in the tube when you make a run. All signs of excessive blow-by. You could hook up your pcv system and, at idle, you should have a slight vacuum ( negative pressure ) in the crankcase. If it's positive, you got excessive blow-by.


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