GS023

I am working on a C5 that was set up for track usage. The car has the vent lines from the valve covers routed to a can to catch oil. From what I understand this is normal for an LS motor. The owner can go out for a 30 minute session and we dump 1/2 quart of oil from the can. Is there a better resolution for this? Any help would be appreciated.

kelp

You need a restrictor to draw vacuum, but no volume.

davidfarmer

you can get Smith Brothers pushrods with restrictors in them, to reduce all of that high-rpm oil being pumped to the top of the motor. I've never had a car pump that much oil out of the valve covers, but it does seem to be pretty common.

If you are losing oil out of the crankase ventilation system, you likely have a leak bad seal on the bottom of the valley cover, under the intake. If the silicon seal is bad, oil can get into the separator.

GS023

Thanks for your help.

GS023

Took the car out to MSR yesterday. Took out about 1/2 quart per session. I like the pushrod idea and hope to talk the owner in to that. One other issue is after a few laps we started to loose oil pressure in hard turns. Never went to 0 but always lifted when light came on. Light comes on at >20 psi. David, (or anyone) is this feasible? We are pumping so much oil in to the valve cover area that were filling it therefore pushing it in to our recovery can and at the same time emptying the pan. We added oil every session usually 1/2 to 1 quart over full. Thanks for your help.

C66 Racing

The catch can is definitely preferable to the oil going back into the intake, messing up your air filter as it drains back down the intake after you shut the car down, and fouling your plugs. I seem to have this issue the most in long, high G, high rpm left hand turns. Seems the oil pools up in the passenger side under the valve cover and then gets sucked into the intake via the vent tube that goes back to the intake.