Questions About Valve Cover Breather, And Coolant Overflow Bottle

[fivespeedsteed]

almost done with my hci swap and have a few questions

the breather hose that goes from the valve cover to the throttle body, is that necessary or can it be capped off at both ends. I do have a pcv valve and all in place, but have read about the motor maybe needing air from that fitting. is this true? i don't want air sucking past seals or whatever the downside of that is. if it is necessary, why? and can i do a vented catch can setup?

ive put in a silla 3 core alum. radiator, and mishimoto dual e fans. i cant seem to find an overflow that will work in this situation. i would like one because i need to park on driveways i cant leak on, and i dont want to run a hose to the ground just straight from the radiator. i bought a canister style one from JD's performance but i think it wants you to weld a tab onto a frame rail up front to bolt it to. i have relocated the battery to the hatch, so the stock battery location is open, does someone make a nice looking setup i can self taping screw into that area? the only way to hang it off the radiator would be from one of the 4 nuts and bolts that holds the fans to the rad, and im trying to avoid some parts store plastic one if i can.

any suggestions?

 

[mikestang63]

To answer your questions

1. Yes you need the vent breather tube for a n/a setup
2. yes youy need the PCV unless youy have a breather/catch can setup
3. You can use the cannister style overflow tank. They normally come with L shaped brackets or simply fab up some

Very bad pic but you can see how I have min on the driver side of the radiator next to the taurus fan

20140808_111327[1]

• mikestang63
• Aug 8, 2014

]

 

[Sharad]

almost done with my hci swap and have a few questions

the breather hose that goes from the valve cover to the throttle body, is that necessary or can it be capped off at both ends. I do have a pcv valve and all in place, but have read about the motor maybe needing air from that fitting. is this true? i don't want air sucking past seals or whatever the downside of that is. if it is necessary, why? and can i do a vented catch can setup?

ive put in a silla 3 core alum. radiator, and mishimoto dual e fans. i cant seem to find an overflow that will work in this situation. i would like one because i need to park on driveways i cant leak on, and i dont want to run a hose to the ground just straight from the radiator. i bought a canister style one from JD's performance but i think it wants you to weld a tab onto a frame rail up front to bolt it to. i have relocated the battery to the hatch, so the stock battery location is open, does someone make a nice looking setup i can self taping screw into that area? the only way to hang it off the radiator would be from one of the 4 nuts and bolts that holds the fans to the rad, and im trying to avoid some parts store plastic one if i can.

any suggestions?

Here are a few parts to look at-

Stock style catch can. You could splice this in between the passenger side valve cover and the throttle body
http://www.uprproducts.com/mustang-billet-oil-catch-can-seperator-79.html

Breather tank for aftermarket valve covers. This is a race style setup, but it can be done as a bolt on setup with valve covers which have ports for breathers
http://www.uprproducts.com/billet-breather-tank.html

Universal coolant overflow
http://www.uprproducts.com/billet-coolant-overflow-tank.html

 

[fivespeedsteed]

so i cant just block off that valve cover port and call it done? does it need to recirc into the tb or does it just need to be able to push or pull air through it?

i have a pcv system on it already, i know i want that.

 

[Chuckman]

the breather hose that goes from the valve cover to the throttle body, is that necessary or can it be capped off at both ends. I do have a pcv valve and all in place, but have read about the motor maybe needing air from that fitting. is this true? i don't want air sucking past seals or whatever the downside of that is. if it is necessary, why? and can i do a vented catch can setup?

the point of that fitting is to let fresh, filtered, metered air into the crankcase that can then be vacuumed out the pcv valve. you do need it if you're using a stock-style pcv system, as just putting an open-air breather there will let un-metered air in through the pcv, basically creating a vacuum leak.

for my rad overflow, i used one of the plastic summit overflow bottles/tanks, and used an L-bracket from the hardware store and mounted it on the drivers frame rail under the battery. keeps it kinda out of sight. before that, i ran one of the basic parts-store pos ones, wont go that route again.

 

[Sharad]

^^I respectfully disagree. The intake manifold pulls air out of the lifter valley via the PCV port in the lower manifold. And it's pretty common to block off the valve cover port on boosted applications where the throttle bottle port is blocked off. I guess I'd say "there's more than one way to skin a cat" when it comes to positive crankcase ventilation on the 5.0.

 

[mikestang63]

^^I respectfully disagree. The intake manifold pulls air out of the lifter valley via the PCV port in the lower manifold. And it's pretty common to block off the valve cover port on boosted applications where the throttle bottle port is blocked off. I guess I'd say "there's more than one way to skin a cat" when it comes to positive crankcase ventilation on the 5.0.

n/a and boosted applications are apples to oranges. Putting a breather element on the VC on a n/a setup will allow unmetered air into the crankcase and can cause a lean condition. It may not be severe but nonetheless will lean it out and as stated causes a vacuum leak. You won't know what your AF ratio is until you put a wideband on it.

open breather element ? | Mustang Forums at StangNet

I dont get why he just doesnt leave the breather tube on and call it a day rather than trying to rethink Ford engineers. The stock PCV system works fine for 99% of n/a setups.

 

[Chuckman]

^^I respectfully disagree. The intake manifold pulls air out of the lifter valley via the PCV port in the lower manifold.

which is replaced via the v/c hose. and since its circulating fresh air into the intake (and then into combustion chamber) it really should be metered with the rest of the air going in, which is why its pulled AFTER the maf in the stock setup.

And it's pretty common to block off the valve cover port on boosted applications where the throttle bottle port is blocked off.

youre right, most forced induction setups are probably better off NOT using a stock-style pcv setup since you dont want to force more pressure into the crankcase and force the seals to leak. this is where an open breather or vac-pump setup comes in. afaik though, the OP is not f/i, and says he's using a stock-style pcv.

 

[fivespeedsteed]

Im trying to cap it because I cut the baffle out of my factory valve covers to clear my roller rockers, so im thinking oil will get up into that barb fitting and then get into my throttle body and gunk things up. Not to mention the explorer tb I got doesnt have the elbow in it at all so id need to hunt for one wothq the elbow for this breather. I dont want blow by oil vapor getting in the tb anyways but your all saying that the pcv valve will cause that fitting to suck air not bleed it?

 

[fivespeedsteed]

so it looks like im either going to need to run a catch can between the valve cover and throttle body or im going to need to find some valve covers with the proper baffle. unless i can find some baffled oil cap somewhere.

anyone know what valve covers will clear my crane pedistal to stud conversion with crane RR's but wont hit my manifold?

 

[mikestang63]

Have you tried using the double thick cork VC gaskets for clearance?