With a Boosted motor what is the most efficient way to releave crankcase pressures. Is the OEM design PCV system efficent enough for 8,9,1000+ HP?

I had a discussion with my step dad about welding a 3/4" bung into each valve cover and then routing each side with- 12 line to their own breather tanks. He said that wouldn't be enough. You'd need 2 bungs per side and a total of 4 -12 lines to 4 breather tanks to be efficent. I think that is way overkill and a big waste of resources. If thats the case might as well use a vacum pump. What should I do?

 

Don't know how much it is good for. My D1SC setup has two vent lines that go down to the air inlet tube near the air filter to help relieve the pressure. Vented valve covers also will help. Mine does fine and did just under 600 to the wheels.

 

Thanks for the reply. I also have a D1-SC, and I just don't want any problems. Anybody else have any ideas?

 

If you haven't yet, you may want to check out my post about my dyno. Interesting stuff on the new air inlet tube for the D1SC.

 

Yeah I read that post. That's a nice inlet.

 

I run a vent line from the passenger side valve cover to an oil catch can then down to the inlet tube on the blower. This stopped various oil leaks but I get so much blowby that the inlet tube and MAF become coated with oil. Won't be long before I need a rebuild - i'm sure it's gonna pop soon.

 

You see that's what I'm afraid of OIL LEAKS!!!! I want somthing that won't blow any gaskets and no oil will be visable on the outside of the motor.

 

Without the vent the car leaked from everywhere - and I do mean everywhere. You better vent it - IMO

 

With only an A-Trim running 7psi, with a standard valve cover breather (not running the breather hose to the intake tube pre-supercharger) it would blow oil past the front and rear main seals everytime you went WOT. Even after replacing seals, it still blew out the rear main. Now this was on a tired motor that shortly thereafter broke ringlands. I recently swapped in a new shortblock, gone WOT a few times, and it appears its starting to push a small amount of oil past the front main seal. I'm going to install the Crankcase pressure evacuation system from Mr. Gasket. I've heard only success stories with this setup. It was only $40 after shipping from Jegs. Not sure if you've looked into that, but it seems to utilize the massive amount of vacuum created by the exhaust flow, so it seems hard to beat. Maybe something for you to look into...

BTW...there's a ton of threads discussing this on the board...i recommend a search...

 

My impression from what I've read on the Mr Gasket/Moroso kits are they only pull crankcase pressure at higher rpm? Maybe I misinterpreted this info? What about at Idle and cruising speeds?

 

Yep, well high RPM, or high engine load...if you go WOT I imagine it'll be pushing enough exhaust to create a vacuum, how strong at low RPM I'm not sure...Maybe someone who actually runs this setup will chime in. I'm also curious where the best place to weld in the tubes will be for max ventilation...

Woah...I uh just looked at you're car domain and such..and paid attn to you're first post...not sure if any of my experiences /nor info really applys to you're application...800+ hp I imagine is whole 'nother ball game when it comes to crankcase ventilation...good luck...

 

OK I'm the dumb one here and quick to ask. I understand where the 2 breathers go on the VC's w/ the grommets, but where do the 4 remaining pieces go as summit's site is ambiguous w/ the details.
Do you also put small filters on the nipples of those breathers or they're just left open like that?

 

I know on my setup, there is two addtional places to vent on the drivers side of the intake manifold. These two places vent from the intake manifold through two different rubber hoses to the inlet tube to my D1SC. When I get my new inlet tube in there I will definatly also incorporate these vent hoses into my new tube near the air filter. Any ventalaiton you can give your motor, the better off you are. The ones on the valve covers help, but may not be enough to preven leaks, especially on a tired blown motor!

 

Isn't that the kit that you weld to the headers for crankcase evac?

 

Yep, it's my understanding that the "chrome breathers" go into the valve covers with those rubber gromets, followed by those "flutted" looking longer tubes being welded into the exhaust manifold/headers at an optimal angle for max vacuum. Then you take those "mushroom" looking short tubes and thread them onto the long tubes you just welded to your exhaust. Now you take heater hose and connect the outlet on the breathers in your valve cover, to the inlet on each mushroom...I havn't looked into it, but I imagine those mushroom's are just one way valves to prevent exhaust reverse flowing into you're crankcase...

If someone has pics of an installed setup, that'd be nice...