Ok so here is the problem. I have a 2002 GMC RCSB that had a 4.8 in and recently switched it out to a forged LS2. My problem comes with the procharger and building pressure in the crankcase. I do have the Procharger Red race valve (open) Currently I have the PCV setup like it came from the factory but I'm still building pressure in the crankcase and I think its pushing oil out of my pan when I build boost. I was wondering if you guys could give me some opinions on what to do. I was looking into blocking off the PCV all together and then putting a filter on the oil fill neck? Does anyone else have a suggestion that might work better. I am looking to up the boost more, but want to get this problem licked before I do. Any opinion is greatly appreciated and thanks in advance.

 

Easiest way is to vent both covers to atmosphere. How you have it now, with the intake connected to the driver side cover, it is pressurizing the crankcase.

 

So unhook the PCV at the intake and drivers side, and block the port on the intake? Do I just leave those ports open or do I rig up a mini filter on those open ports? Or maybe run a catchcan with a breather?

 

I put a filter on the passenger side filler tube and a catch can with a breather on the driver side and blocked off the intake port. The good side about this way is its very easy, and doesnt pressurize the crankcase. Bad part is it doesnt pull fumes out of the crankcase while under vacuum.

Having it not pressurize the crankcase and still pull fumes under vacuum requires a couple check valves.

 

Is it bad to have fumes in the crankcase while in vacuum? I don't mind the extra work because I want to get this right before I change out the gaskets and turn up the wick. I'm assuming you tied your catchcan to both ports on the covers? Does the catchcan need to be hooked up anywhere else since it will be venting both heads along with the filter in the oil fill cap?

 

No I just have a hose from the driver side cover to the can and the can has a breather on top...basically a remote mount filter.

Well, it can lead to some acids forming in the top of the engine and shortening oil life....I change my oil pretty often so im not worried about that. There is power to be had by pulling a vacuum on the crankcase since you are basically sucking down the piston on the intake stroke.

 

So almost like having a vacuum pump might be a better option? If I could really have it, I would like to rig it up and not have to worry about it, and just be able to change the oil every 3K or after a couple months. This isn't my daily driver, but I do occassionally make some long drives in it.

 

Exactly, but from what ive heard vacuum pumps are tempermental, need to be rebuilt often, and are basically just finiky. I would just do the 2 breathers. If you get an oil smell (I dont) then you can put in a catch can between the filter and procharger, and the driver side cover.

 

So block off all the ports and put a breather on each valve cover? Do you happen to have a pic of how your's is setup? I appreciate all the info its definitely giving me ideas.

 

You can see both breathers in this pic.