Header evac. bung...where to weld?

Quote:

---

Just one side, passenger, thinking to avoid trans. linkage.

Eight o'clock on that side and looking at it from the rear?

Thanks...Joe

---

Map out the hose routing and see where it works out
the best... try to split the distance between the end
of the primaries and the end of the collector... if
you keep the check valve in the collector you will
burn it out if you have back pressure from the exhaust
and if you plan on running the exhaust at the track
you better check the back pressure first... anything
over 4"hg it would be a PROBLEM... if the pressure is
to much you will start to pressurize the crank case

Quote:

---

I put it to the outside of the car and you can Tee from both valve covers to draw from both sides.

---

Remember that with this set up your looking for volume..
the crank case is a fairly large area... the bigger the
tube and hoses the better

Quote:

---

Hi guys, need to put a evac. bung in my headers and need some experiences on where it will have the least interference
with floor pan, frame rails etc.

This is on a 70 Charger, 440, Hooker Super Comps. 1-7/8" 727.

Haven't had the engine in yet so don't have a feel for the best location.

I'm going to use the normal PCV to intake manifold for the street
but want to hook PCV to the bung for the track to preclude any
oil messing up my mixture.

Anyone have this set-up or can give me some guidance so I can do this once, correctly??

Thanks,

Joe

---

Despite what some may say, there is no correct way to to combine an open crankcase evac system ( PCV ) with a closed system (exhaust evac system ). The exhaust evac system is not ment to be run with a full exhaust system. No matter how sophisticated it is or where you mount your evac bungs, with a full exhaust system, your check valves will be under pressure most of the time - until they burn through that is. So, the exhaust system will, for the most part, just be going along for the ride. The exception might be at idle or maybe slightly above idle, when the flow past the bungs creates a vacuum greater than the back pressure. With the PCV tied in, manifold vacuum would probably pull the check valves closed anyway. At any rate, for the most part, the exhaust evac system will be pretty much useless and the PCV system will pretty much work as designed. The bad thing is the exhaust check valves burning through - not only pressurizing the crankcase, but possibly feeding hot exhaust gas in to the intake manifold via the PCV valve, which is tied in. In regards to running the combined systems with open headers; you just took a closed system (exhaust evac ) and put a hole in it ( PCV ) making it not very efficient. As far as bung location goes, most suggest an arera right where the primary pipes converge in to the collector and at a 45 degree angle down stream. I actually located mine in the collector extension. At idle with a very scimpy exhaust system, I can pull about 3-4 " of H20 vacuum. Anything above about 1500rpm, the check valves close under pressure and the crankcase starts to build pressure pretty rapidly ( closed system). Mine is a race only application. I only run an exhaust system past the collectors when I am running the engine in my garage at home for some other test purpose. Even at that, I test and once a year replace ) the check valves as a failure there can have bad consequences.

Quote:

---

Water monometer testing my exhaust evac system with a "full" exhaust system installed. Goes under pressure at about 1500 rpm.

---

From the data you show your exhaust is quite restricted
and I assume you did that for the neighbors... I know
my buddies son runs them on the street but I dont
know how high he turns it on the street

Quote:

---

Water monometer testing my exhaust evac system with a "full" exhaust system installed. Goes under pressure at about 1500 rpm.

---

With all the exhaust system hype that goes around, wonder how many actually measure back pressure. A questions for your buddies. Off my 3" collectors my system is 3" to 2 chamber 3" in and out mufflers to turnouts in front of the axle. As I said, any back pressure at all closes those valves and then you got nothing except a pressurized crankcase - often accompanied by lots of oil leaks . In order for the crankcase to vent, it has to overcome the exhaust back pressure. Actually, the PCV system is a very efficient ( and forgiving ) system. It really wasn't designed as an evac system, but an emissions system ( why it often gets a bum wrap). When it's suckin, it does maintain a very slight vacuum in the crankcase. If your motor is a little tired, it will vent to the atmosphere ( breather), or the air cleaner ( inlet side of the carb )at higher rpm's. IMO, the next best thing to running a pcv system for the street is to just vent both valve covers to the atmosphere - via old school.

Quote:

---

Quote:

---

Water monometer testing my exhaust evac system with a "full" exhaust system installed. Goes under pressure at about 1500 rpm.

---

With all the exhaust system hype that goes around, wonder how many actually measure back pressure. A questions for your buddies. Off my 3" collectors my system is 3" to 2 chamber 3" in and out mufflers to turnouts in front of the axle. As I said, any back pressure at all closes those valves and then you got nothing except a pressurized crankcase - often accompanied by lots of oil leaks . In order for the crankcase to vent, it has to overcome the exhaust back pressure. Actually, the PCV system is a very efficient ( and forgiving ) system. It really wasn't designed as an evac system, but an emissions system ( why it often gets a bum wrap). When it's suckin, it does maintain a very slight vacuum in the crankcase. If your motor is a little tired, it will vent to the atmosphere ( breather), or the air cleaner ( inlet side of the carb )at higher rpm's. IMO, the next best thing to running a pcv system for the street is to just vent both valve covers to the atmosphere - via old school.

---

I just run a pair of breathers on the covers on my
Rampage.. its a street mainly car