Header evac system to rear intake breather?..

[cjshaker]

Would running a header evac system work ok if it was ran to the rear breather hole on an intake? I know some good baffling would be required, but I think that's do-able. Everybody runs them to the valve covers, but I think the intake would serve the same purpose since the valve area is only open to the lifter valley anyway.

I'm trying to brainstorm an evac system for an engine that would be ran on the street (think Drag Week). My thoughts are to run a regular breather on the rear of the intake that could be quickly popped off and hooked up to the 2 lines for the header evac system. I don't want the added complexity and cost of a vacuum pump, and this would keep from adding cluster to the engine compartment and make valve cover removal simpler and faster. Stupid idea or a waste of time?

[blykins]

I don't see why it wouldn't work.

Some guys also hook them to a fuel pump block off plate, but it has to be baffled REALLY well....

[e philpott]

I been pondering it too for a few years .. front oil fill or rear breather ?or both ?  , since I've been running the smooth F O R D valve covers I lost my Evac hook up and would like to have it functional again

[gt350hr]

   If you ran the valley tray ( many don't) it would help a bit. An additional "surge"  baffle could be added to reduce oil in the area. The vacuum created by the headers is far less than that of a vacuum pump or dry sump pump so it should be fine.
    Randy

[Falcon67]

X2 - you might could cobble up a air/oil separator deal to help, but you won't have near the oil movement out on header evac that you will with a vacuum pump. 10 passes with the dragster at 8 in/hg using a vacuum pump will put about 1/3~1/2 cup of oil in the catch can. 

[JamesonRacing]

I used the rear manifold opening for a PCV pickup on my street car, but, when at the track, about 1/2 track the lifter valley would retain enough oil that I was pulling it into the intake, leaving a smokescreen behind me.  I run a wet-vac pump on my race car and it works great.

[Joe-JDC]

A couple of pointers if you do.  The Moroso evacuation kit has instructions on how to install the pitot in the collector, and if you use their kit, make sure you follow their instructions perfectly.  I tested the pitot at several angles, and depths, also turned it around every way possible, and found the most vacuum was per their instructions.  On my flow bench, I could get the pitot to pull as much as 40" on the manometer.  The whistle depth is critical, and angle needs to be exactly 45*, or as close as possible.  There is a rubber grommet that fits down in a standpipe that has a slit in the bottom which will help with oil separation and loss of oil.  Joe-JDC

[cjshaker]

Good to know it wasn't a stupid idea..lol
I already have the stuff for the evac system, so all I have to figure out is a quick way of connecting and disconnecting the breather/evac lines. That won't be too difficult...I think.

   If you ran the valley tray ( many don't) it would help a bit. An additional "surge"  baffle could be added to reduce oil in the area. The vacuum created by the headers is far less than that of a vacuum pump or dry sump pump so it should be fine.
    Randy

I always run the valley tray when possible, but with the PSE intake, I don't know if it'll be possible, so you bring up a good point. I'll have to come up with a really good baffle system, especially when G forces will be pushing the oil to the rear of the lifter valley. Some sort of homemade "surge" baffle in the lifter valley would definitely help.

...since I've been running the smooth F O R D valve covers I lost my Evac hook up and would like to have it functional again

This is why I want to do it. I am pretty set on keeping the old school look, and I want to use a set of the baldie valve covers, so I was looking for another way to do the evac system.

[cjshaker]

A couple of pointers if you do.  The Moroso evacuation kit has instructions on how to install the pitot in the collector, and if you use their kit, make sure you follow their instructions perfectly.  I tested the pitot at several angles, and depths, also turned it around every way possible, and found the most vacuum was per their instructions.  On my flow bench, I could get the pitot to pull as much as 40" on the manometer.  The whistle depth is critical, and angle needs to be exactly 45*, or as close as possible.  There is a rubber grommet that fits down in a standpipe that has a slit in the bottom which will help with oil separation and loss of oil.  Joe-JDC

Joe, I had done a little research on that and saw their recommended installation guidelines. I'll follow them as you mentioned.

[mbrunson427]

Did this on the drag car, it worked too well. Just as stated above about the smoke screen. If you do this, definitely need to run one of those steel wool buckets underneath the the PCV plate so you don't suck in a bunch of raw oil......still might. You could easily make a restrictor plate.

We abandoned the system entirely because the exhaust dump was in front of the tires and it seemed like an extra bad idea.

[Barry_R]

Tried it in the valley and it really tossed up a lot of oil - did not work even with baffles.  Seems like there is a lot more oil action in that area than you would expect.  Tried running a vacuum pump at the fuel pump mounting boss once - same problem - apparently the chain throws a LOT of oil out sideways at higher RPM.  There is a good reason that 90+% go through the valve covers....

[afret]

Won't work well at the back of the intake.  When the car launches, a whole wall of oil gets pushed to the back under the intake.  It ends up like sticking a straw into liquid and oil will go straight into the evac line even with good baffling.  Great for killing mosquitos.

[cjshaker]

Ok, I'll have to give this some more thought. Maybe an air/oil separator will do the job, like Chris mentioned. They seem to work good in modern engines for the PCV system.

[e philpott]

Those clear Valve Covers with the breather installed might be my ticket , lol  , I'm thinking Blair told me that there was a lot of Oil back there a few years ago like these guy's are saying , I wonder how the front Fill Tube would work in that case ?