misterp Posted November 13, 2009 Report Share Posted November 13, 2009 (edited) This last week I've been researching and ordering a TON of PCV valves trying to find one that incorporates a built-in check-valve so boost pressure is not allowed to enter the crankcase. You gotta be a man free of embarrasment to stand at the Oreilly's counter and blow through a bunch of PCV valves as the parts guys are staring at you. Anyways after looking at lots of aftermarket and OEM pieces I have found ONE that for sure seals completely, the Ford OE PCV valve on the supercharged T-Bird, available only at the Ford parts counter as FoMoCo PN E5ZZ-6A666-A for $10; you must get the actual OE FoMoCo valve, the aftermarket Autolite equivalent does have a check valve but WILL NOT seal out boost. I have read that the OE PCV valve used on the Toyota Supra is also a positive one-way PCV valve but I haven't ordered one to give it a test. The FoMoCo valve is a direct replacement on the '03+ LS motors. At present our recommended PCV system configuration for FI/nitrous-equipped LS motors is: 1) replace the empty OE PCV valve with the Ford one; 2) install a catch can between the PCV valve and the intake manifold; 3) remove the fresh air PCV hose (passenger valve cover) and cap both the valve cover and throttle body nipples; 4) use a breather-equipped oil fill cap, allowing fresh air for PCV under vacuum and blow-by venting during boost. These 4 steps positively remove any chance of oil vapor entering the intake manifold provided your catch can is up to the task, and it can all be done for 100-150 bones. This is an essential mod on ANY forced induction or nitrous engine to prevent increased detonation risk due to oil ingestion; on NA motors this will keep the intake manifold and valves from totally gunking up with tar deposits. Installing a catch-can between the PCV valve and the intake manifold is a common mod in almost all gearhead circles; but that's only a job HALF DONE - what most don't realize is the PCV system REVERSES FLOW DIRECTION at WOT on a N/A motor, to be exact the ONLY setup where the PCV circuit will not reverse direction is on a positive-displacement blower (Radix/TVS) where the PCV valve is plugged into the intake elbow, just behind the throttle body and ahead of the rotors themselves (there is always significant vacuum available there). Because of this reversal of PCV flow, instead of crankcase gasses being sucked into the engine via the PCV valve, the PCV valve will temporarily be admitting fresh air and crankcase gasses enter the intake manifold through the throttle body nipple, and the problem will be made worse if there is excessive blowby pressure. If you ever wondered why the hell the back of your throttle body looked like the Exxon Valdez spill, now you know why - because during WOT the factory PCV system reverses and oil vapor pours in from the passenger cover. Likewise, on a turbo/centrifugal application the boost pressiure in the intake manifold is transmitted via the PCV plumbing and pressurizes the crankcase, blowing oil vapor out every gasket & seal & ejecting the oil dipstick, and the bottom-half of the motor gets nasty looking and begins leaving drip spots everywhere you park... DO leave the PCV system installed and functioning, without it your engine oil life will only be 1/3rd of normal and your engine wear will go up significantly due to increased crankcase contaminants. Mr. P. Edited November 13, 2009 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
chpspecial Posted November 13, 2009 Report Share Posted November 13, 2009 I don't know about the front mount kits and how they remedy the passanger side PCV line but the STS kits have a fix for this. In line with passanger side tube goes a two way solenoid and a hobbs switch. As soon as the hobbs switch reads any possitive pressure, i.e. boost >1psi, it sends a signal to the solenoid. The solenoid then closes boost off from entering the valve cover and vents it to atmosphere. Just like your vent cap Idea. IMO this method keeps the PCV system running as originaly designed with out letting boost into the valve cover. And is why STS kits are still street legal Quote Link to comment Share on other sites More sharing options...
misterp Posted November 13, 2009 Author Report Share Posted November 13, 2009 I don't know about the front mount kits and how they remedy the passanger side PCV line but the STS kits have a fix for this. In line with passanger side tube goes a two way solenoid and a hobbs switch. As soon as the hobbs switch reads any possitive pressure, i.e. boost >1psi, it sends a signal to the solenoid. The solenoid then closes boost off from entering the valve cover and vents it to atmosphere. Just like your vent cap Idea. IMO this method keeps the PCV system running as originaly designed with out letting boost into the valve cover. And is why STS kits are still street legal 2 criticisms (not personal, but about the STS kit) - 1) venting *anything* to the atmosphere under any condition is unlawful in all 50-states - not that I agree with doing this, but you're supposed to plumb all venting so it re-enters the intake manifold to be burned STS does carry a CARB number on a couple of their systems so they must be re-introducing this oil blowby back into the intake manifold. 2) the Bosch solenoid is lifted directly from the BMW, and I seriously considered using this idea too but the M-guys just have hell with these valves, they are known to be one of the most troublesome pieces on the whole car, they are not very reliable. Mr. P. Quote Link to comment Share on other sites More sharing options...
04CHASE Posted November 13, 2009 Report Share Posted November 13, 2009 nice find P , i have to agree on the sts setup to me something less to have to wire up also is nice. i need to figure out what i am going to do with my new setup , i have 2 -10 male fitting on my new covers so im going to have to get a check valve for them or just plum the pre turbo . I also may just run breather and catch can setup on it. well one thing i have is time . cant wait to drive my pos again . i think this year i put less than 100 miles on it. Quote Link to comment Share on other sites More sharing options...
hossram64 Posted November 14, 2009 Report Share Posted November 14, 2009 So your saying cap off the passenger side valve cover and cap off the throttle body port. Then run the drivers side valve cover threw a catch can and then back into the intank. I have a procharger and on there set up the passenger side line runs into the inlet right before the head unit should I just cap this also? If i cap the passenger side do I have to use a breather cap for the oil fill cap? Quote Link to comment Share on other sites More sharing options...
misterp Posted November 14, 2009 Author Report Share Posted November 14, 2009 So your saying cap off the passenger side valve cover and cap off the throttle body port. Then run the drivers side valve cover threw a catch can and then back into the intank. I have a procharger and on there set up the passenger side line runs into the inlet right before the head unit should I just cap this also? If i cap the passenger side do I have to use a breather cap for the oil fill cap? Yes! Yes! And, Yes! You got it! Because Procharger runs that fresh-air line to the inlet of the supercharger, it means that during WOT the boost in the intake + natural blow-by will make its way into the compressor inlet, oiling up your compressor, intercooler, intake manifold, heads, and increasing risk of detonation. Check me on this, remove the inlet elbos from your compressor and see if there is evidence of blowby oil in the compressor... Mr. P. Quote Link to comment Share on other sites More sharing options...
hossram64 Posted November 14, 2009 Report Share Posted November 14, 2009 right now I have the passengers side hose going to the catch can then from the can to the procharger so there is no oiling. When I do cap these and change it around do I need a breather cap or can I just use the regular oil fill cap. Quote Link to comment Share on other sites More sharing options...
misterp Posted November 14, 2009 Author Report Share Posted November 14, 2009 right now I have the passengers side hose going to the catch can then from the can to the procharger so there is no oiling. When I do cap these and change it around do I need a breather cap or can I just use the regular oil fill cap. Installing the catch can was a smart idea; go ahead and continue running 2 catch cans then since it's working for you. Yes, if you choose to remove that line you will need to put a breather on the valve cover (oil fill spout). Mr. P. Quote Link to comment Share on other sites More sharing options...
hossram64 Posted November 14, 2009 Report Share Posted November 14, 2009 thank you for your help and clearing everything up for me. I've been running my catch can wrong this whole time lol I only have one catch can and have only had the passenger side line running to it. I'm wondering if I can splice into the driver side line and have both lines go threw the one can?? Quote Link to comment Share on other sites More sharing options...
misterp Posted November 15, 2009 Author Report Share Posted November 15, 2009 thank you for your help and clearing everything up for me. I've been running my catch can wrong this whole time lol I only have one catch can and have only had the passenger side line running to it. I'm wondering if I can splice into the driver side line and have both lines go threw the one can?? Well, I think a lot is getting lost in conversation; let's think this out visually. Only thing you need to remember - air will always flow from high pressure (boost) to low pressure (vacuum). From what I read, this is how you have your PCV system plumbed right now: And here is what is happening when you mash your foot to the floor: At a minimum, I would install the Ford SVO Motorcraft PCV valve, like so - you'll still be feeding blow-by into your compressor but at least you'll stop pressurizing the crankcase, and it will retain smog-legality: Now, if you want to remove ALL chance of oil ingestion, you might consider re-plumbing and adding a vent: And the operation of the same setup under boost (not emissions legal because of the vent) - Mr. P. Quote Link to comment Share on other sites More sharing options...
AKSSS Posted November 15, 2009 Report Share Posted November 15, 2009 Mr P. Do you have a easy to get ahold of breather cap that twists right into our valve covers? Or just a 1in 1/4 pushin setup or something. Quote Link to comment Share on other sites More sharing options...
misterp Posted November 15, 2009 Author Report Share Posted November 15, 2009 (edited) Dan and I MacGyver'd our own from the original oil fill cap, a small $11 breather at Oreilly's, and the factory PCV valve like so: * scuff the top of the original cap with 180-grit * scuff the underside of the breather (mating surface) with 180-grit * drill a 7/8" hole through the middle of the cap * epoxy the breather to the cap with JB-Weld * modify the original PCV valve, drill a 7/16" hole in the engine-side of the valve * stuff steel or brass wool in PCV valve to act as an oil strainer (make sure it won't ever fall into the engine!) * silicone the modified PCV valve to the breather * replace your re-purposed PCV valve with the Ford SVO one Or, you can pay $40 to Scummit Racing for this breather. Mr. P. Edited November 15, 2009 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
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