DIRTYLSXSS

what the best way to vent a carbed motor. I see some with nothing, some with breather on fill cap, some with catch cans.

whats the best way or does it need it?

Doug G

I had both valve covers Teed to the rear of the intake like a SBC would be...unsure why, but the dip stick was pushed out spraying oil everywhere on it's 1st track pass....not fun.
I have now added a breather to the oil cap, and teed both valve covers to a oil/air separator which is vented to free air by a breather on top of it.

No issues since.

TTur1996

We have a Mighty Mouse catch can. It is set up just like Doug's, but has another line that goes above the carb. We run an air cleaner and have a spacer that goes between the carb and the air cleaner, that has been drilled and tapped for a AN fitting. It pulls enough vacuum, that after driving it around for a half hour or so, you will have to empy it. It is full of water. It also has a breather on top of it. So if for any reason you get excessive pressure that the vacuum can't handle, it has a bypass valve that opens and exits the pressure through the breather. Its hard to believe how good it works, getting the moisture out of the motor. They call it a draft setup. There are three different ways you can set it up. One is with a pcv valve. One is draft, and I can't remember the other one. Very versital. But to answer you question. Yes I would put something on there for sure.

jimmyp3353

iTrader: (3)

I have PCV on drivers valve cover going to the rear of the intake, and a breather where the oil fill is.

homemade87

I use a ls6 valley cover with the built in pcv . I run it to the intake . Then I put 2 small breather/filter on both valve covers . Air in at the valve covers pulled thru the valley cover . I found if I put a hose on the valve cover and hook it to any part of the air intake system it will pull oil out of the valve cover . This has controlled oil consumption for me . No catch can . 3 motors this way .

ZONES89RS

iTrader: (25)

Going with catch cams from now on like what Doug has. The mike Norris cans work well for running to the intake. But I want something bigger with more capacity. Used to run a air water separator but it I wasn't enough.

fast89stang

iTrader: (2)

Crankcase evac to headers. Custom modified ebay valve covers, no oil out pipes and will suck a dollar bill thru fill cap when running. If you don't pull the fill cap when draining oil, it will take forever. It also is the easiest, cheapest way to increase et.

DIRTYLSXSS

ty for the replies think im going homemade87's way to start with and go from there.

this thing is going in 1/4 miles circles not straight

TTur1996

We never get any oil in our catch can. Only water. We have never pushed any gaskets or dipstick or anything either. And that's at 14:1 compression too. I'm not sure what you mean by (controlled oil consumption). Leads me to believe you are either pushing or pulling oil into the intake and burning it. Our motor has 0 oil consumption. I have read many instances where people push oil into the intake the way you have it. That's why after doing a lot of research we went with this method to evac. So I guess what ever works for you.

TXsilverado

iTrader: (18)

I ran a small vent to the driver's valve cover and a LS6 valley cover pulling vacuum from the intake.

Pop N Wood

iTrader: (1)

Same here

fast89stang

iTrader: (2)

mine picks the car up a tenth a second. I don't know about any other way, but 30 bucks for cheap horsepower.

imma_stocker

iTrader: (19)

Had a small engine fuel filter from local parts store inline from LS6 valley port to manifold port for vac source. Filled it with oil after test drive around the block at partial throttle. Since then I've added a basic catch can and no more oil collecting in the small inline filter.

It goes: LS6 valley port -> catch can -> inline filter -> manifold port. No check valves needed so far. LS6 port spits oil, not as clean outlet as some think so it needs filter, catch can, or separator.

Both valve covers have a small air filter. Visible oil vapor comes out of the filters at idle.

TXsilverado

iTrader: (18)

I'll bite. how does venting the crank case to the exhaust increase hp?

pdxmotorhead

Check valves allow the pressure to go into the exhaust, the exhaust actually creates suction, the vacuum in the crank case helps with lowering windage and helps the rings seat at high RPM.

The down sides:
you need to make sure you vent after the cat and O2 if you have them or they can oil-foul.

Similar to adding a crank case vacuum pump. (Or a dry sump) but some places don't allow the exhaust extractors at tracks because if you roll and the engine runs it can blow flaming oil out the back..

Doug G

Headers and an E-vac kit I thought was reserved for low tension rings and creating a better seal ? (and this is what "made" HP)

fast89stang

iTrader: (2)

My rings are stock. But on my last 4 engines that have been in my car, it will pick up a tenth. One 302 I had in it, we got to track late after I installed the kit. I got no time trials. I dialed the car almost a tenth faster than it normally ran just to be safe.....I made it to 4 cars that day, as the tenth worked out about perfect. I don't know if its the same since my exhaust is ran all the way back now, but with bullets straight to collector, it works. I know it still has good vac at valve covers, at idle it will hold a dollar bill, rev it and it will try and suck it in the oil fill hole.

TXsilverado

iTrader: (18)

is it a kit that you use? what does the check valve do?

Doug G

Yes, I'd like some info too.
I could take the filter off the air/oil separator and run a line to the header from it since I have bungs on each header and only run 1 O2 sensor

EDIT:
http://pitstopusa.com/c-131849-engin...n-systems.html

So do you have a vented cap or stock cap ?

fast89stang

iTrader: (2)

The kit is just a generic jegs 30 dollar kit. The check valves keep the exhaust pressure from getting into the motor. But the pipes in the header need to be welded in at a angle, with the slash cuts a certain way, and they say it wont work well if you have full exhaust or any kind of restrictive exhaust. I have full exhaust, but have the mini bullets. Also, some people run them without check valves with no problems. Its just a check valve from a a.i.r set up from the mid 80s smog era cars. I don't guess I should give out all the secrets, and others may work well, but its the cheapest tenth Ive ever gained.