I'm losing around a quart of oil every 1500 miles. If I'm reading the plugs right it's being burnt off. I'm running quite a bit of overlap on my cams. Vacuum is what's needed to help keep negative case pressure correct? With a lot of over lap you lose vacuum pressure? I have the stock breather box on the back of the block and its a little wet with oil around the nipples where the hoses go. Would an aftermarket breather setup work better? Its a ls/VTEC. Thanks.
Edit: the build has around 4-5k miles on it.

 

Yes they do help with oil consumption but only by relieving crank case pressure. If you have an oil control ring issue or a valve seal issue a breather tank will not help. They also work great at keeping the oil out of the intake system. Endyn makes a nice vent tank. I used their setup but with a different vent tank.

 

the crankcase will never have vacuum. if it does, something is wrong.
more valve overlap typically reduces intake manifold vacuum at idle, totally different system.

but as neal said above, the only way a breather box reduces oil consumption is if you run a high power setup that gets a lot of blowby and would typically create positive pressure in the crankcase. an aftermarket setup using a larger vent hose or multiple hoses allows more airflow thereby eliminating positive crankcase pressure.

 

Crankcase is supposed to have vaccume that's how the pcv works, the box on the back of the engine is supposed to seperate out the oil vapor in the pcv line

 

I'm using royal purple. I've done some reading and some say it burns quicker than some other oils.

 

no, the pcv is a one way check valve, the intake manifold is supposed to have vacuum, and sucks air through the pcv from the crankcase to use any unburnt fuel vapors that reside in the crankcase. the crankcase is only supposed to have vacuum if you cover the vent hole with your finger. the vent hole is there to provide the air supply to allow for the air movement though, and is designed so there is no vacuum or pressure when not plugged by your finger.
plugging the vent and feeling vacuum while the engine is idling is just how you know the pcv is working and the engine is in somewhat decent condition. but if you were to somehow install a vacuum/boost guage to the crankcase, under normal conditions you should never see any vacuum or pressure. if you see vacuum, that means the vent is clogged. if you see pressure, that means the engine is wearing out.

 

^^^ that is correct.