Venting crankcase pressure?
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 5,423
Likes: 43
From: Daytona Beach/ Atlanta---- Good Ol' Florida Boy/ Georgia
Venting crankcase pressure?
I have a ZR1 and when I push it hard it push some oil out of the rear main seal. I'm assuming crankcase pressure is really high. What's the proper way to vent the system? I have one catch can on the car going from valley cover to behind the tb.
Also does this mean the seal is completely shot?
Also does this mean the seal is completely shot?
Melting Slicks
Joined: Aug 2005
Posts: 2,960
Likes: 112
From: New Braunfels TX
What you can do is vent off the valve covers to get rid of the excess crank case. Get Ron and them to weld you a -10 OR -12 bung and run it to a vented catch can inside the fender.
Last edited by JMBLOWNWS6; Jul 8, 2013 at 01:16 PM.
Pro
Joined: May 2007
Posts: 532
Likes: 7
From: north vancouver british columbia
Use a catch can and have the the valve covers vent through catch can to between TB to air filter, at high RPM you should get a few pounds of vacuum there so you actually will get the engine sucking the crank case pressure out, through catch can is best to prevent sucking in oils.
Le Mans Master
Joined: Feb 2009
Posts: 5,169
Likes: 199
From: Your Sister's Bedroom
People go overboard with the size fittings needed. For most those stock elbows will work just fine.
Safety Car
Joined: Dec 2009
Posts: 4,754
Likes: 303
I agree, just vent the valve covers... But a -10 or -12 is nuts. I've used -6 and -8 to 24psi using just the factory nipples on the valve covers in the past and its worked great.
People go overboard with the size fittings needed. For most those stock elbows will work just fine.
People go overboard with the size fittings needed. For most those stock elbows will work just fine.
And maybe it was -12 to -10... I can't remember. Whatever the moroso can fitting is.
Last edited by turbotuner20v; Jul 8, 2013 at 04:16 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 5,423
Likes: 43
From: Daytona Beach/ Atlanta---- Good Ol' Florida Boy/ Georgia
Burning Brakes
Joined: Aug 2009
Posts: 841
Likes: 0
From: DFW Texas
I have a ZR1 and when I push it hard it push some oil out of the rear main seal. I'm assuming crankcase pressure is really high. What's the proper way to vent the system? I have one catch can on the car going from valley cover to behind the tb.
Also does this mean the seal is completely shot?
Also does this mean the seal is completely shot?
Le Mans Master
Joined: Aug 2004
Posts: 5,972
Likes: 48
From: NCM Lifetime#2195 Bulverde, Texas 78163
St. Jude Donor '13
The original setup was holley valve covers w/ a nipple on each running to a small vented catch can. Then a line running from the valley to the intake manifold through a catch can w/ a check valve (what I would consider the typical boosted dual can setup). At 20psi it still pushed oil. I replaced the driver side valve cover oil cap w/ a -14 to -12 adapter and ran a push lock hose to the moroso can. It was the easiest way to do it, and only required 1 hose on one cover. Maybe could have gone smaller, but it was a good fit for repalacing the oil cap w/ an AN fitting.
And maybe it was -12 to -10... I can't remember. Whatever the moroso can fitting is.
And maybe it was -12 to -10... I can't remember. Whatever the moroso can fitting is.
