When I was at the track I saw a few solid axle gasser type cars with their headers exposed. I noticed lines on both valve covers going directly to the header.
I assume this works like some sort of vacuum suction function to pull crankcase pressure or a PCV type of system.
Do they do this because they can't run a breather/PCV setup?
or?
I get alot of hydrocarbon contamination from blowby, and alot of oil spill from my breather. I run a PCV on the pass side, and an open breather on the drivers.

This seemed like a sort of interesting freebie going on here, even if its not the best looking thing.
After I saw it, I took a closer look at some other cars, and noticed more of this.
Can any of the more hardcore drag racing guys fill me in on why they do this, etc etc?

Just curious..

Matt

It will only work on an open exhaust car. As you can imagine any sort of back pressure would cancel the effect.

Steve

Didn't think of that part of it Steve.

Guess that cancels any "bright ideas" I had for the day..
I wonder what I'd pick up with open headers anyway, other than a headache..

Matt

An old trick was to use the Chrysler vacupans on the street. Run into the header they work fine, just won't pass emissions so dropped.

I can personally vouch for the "won't pass emissions"...I had a 340 Duster set up with pan evac, and sold it not long after I moved to SLC, and the guy that bought it couldn't get to pass the smog test. I told him to try removing the pan evac system, and she passed just fine. graemlins/beers.gif