Hello I’m trying to install an adequate pcv system in my Hemi. I am using a Mopar Performance efi manifold with a 4150 flanged throttle body. The pcv port is located directly under the fuel rail with only enough clearance for a tiny Toyota plastic valve. I’d like to plug that hole and make a hole in my plastic valve cover, but I’m not sure if that’ll work correctly. Thoughts?
Hemi Pcv
- Thread starter lefty70
- Start date
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Suggest post a photo of the area.
Camshaft, idle vacuum..kinda,tells us basic....
I can, my question is could I relocate the pcv. There isn’t enough room for one in the existing hole. There was an install kit available for the intake at one point, no longer available. Imagine the hole directly under the RH fuel rail with about 3/4” clearance. It’s a stock 2003-2008 style crate motor.
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famous bob
mopar misfit
I don`t see why u couldn`t install it between the rockers for clearance, and add a splash plate.
The red arrow shows the small pcv hole. It directly inline and covered by my Arrington fuel rail.
famous bob
mopar misfit
wow, sounds like a well thot out piece. maybe a special pcv for it ??
Yeah they had an install kit. No longer available. I work at a dealer and have looked at every pcv for possible fitment. I’m thinking I could also install a 90 degree elbow then use an inline pcv, maybe?
Hellcat Cuda
Well-Known Member
That manifold was used on the first MP 5.7 crate motor. I had one for the start of my build (evolved to a 6.2 HC). I'm pretty sure it had a 90 degree nippled fitting for an in line valve. I'll find my original paperwork that came with that engine. There's pics, etc.
Awesome!!!
Hellcat Cuda
Well-Known Member
So I could only find about half of my documentation from the MP 5.7 crate I had. I was able to find only one, very clear picture of the manifold that shows that port. However, it the carb version of the manifold but should still help. There is a straight, pressed fit, nippled fitting in that port for a hose with in line PCV valve. I remember a similar, but 90 degree fitting in the one I had.
I think if it were my manifold, I would tap the hole and screw a 90 degree brass fitting in there and then put an in line PCP in there. Hope this helps.
I think if it were my manifold, I would tap the hole and screw a 90 degree brass fitting in there and then put an in line PCP in there. Hope this helps.
Hellcat Cuda
Well-Known Member
This port goes into the head area that is exposed to the crankcase. It's not a vacumn port.
That's the same decision I've made. I'm going to take the manifold off to tap it. I can't think of a way to keep debris from not getting into the crankcase without. thanks for looking into this sir.
Buschi340
Well-Known Member
true. It goes straight down into the pan. I put there a hose to an " Overflow bottle with breather "
1973Barracuda
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Any pics of that ?
Map63Vette
Well-Known Member
I know this is a pretty old thread, but hoping someone might still be listening. I suspect I might have an issue with the PCV system I rigged up on my ModMan intake. It has some tiny 1/8" NPT ports for the breather similar to the Mopar manifold, but I had no idea what valve to use. I grabbed something from the parts store for a similar sized engine thinking that might be a good start, but I'd be curious to see what the original Mopar kit looked like if anyone has pictures or part numbers. I would like to use something more like an inline valve, but wasn't sure how they might work as I believe a lot of valves are orientation specific and require gravity for them to close properly. Would be nice to know what valve was included with the Mopar kit to see if I could adapt it to my setup.
DionR
Well-Known Member
Map63Vette
Well-Known Member
Yeah, I don't have a stock intake anymore. It sounds like Mopar made a kit to work with their carb manifold at one point, which I think I could probably adapt to work with my setup, but I can't find part numbers for it anywhere to even see what was in it or how it went together. Was hoping I might be able to use it for reference at least.
DionR
Well-Known Member
I run a modified catch can. The pcv valve is plugged into the top of the can,the vacuum supply for the valve goes to upper intake manifold fitting. It pulls crank vapors from the fitting under the fuel rail to the side of the can. I learned early on not to put direct pcv vacuum on that port. It will suck oil right off the exposed valvetrain. I installed a breathable oil cap and a vent from the oil fill tube to the air intake tube. Using a prefix single plane 4150.
Map63Vette
Well-Known Member
Hmmm, I never thought about putting the valve on the can itself.
To give some context, when I first did the engine swap I just ran a breather on one of the intake ports and plugged the other. It worked, but it was always messy around the breather. I later decided to put in a DIY catch can (a stainless steel water bottle with some fittings screwed in and steel wool stuffed inside), but still didn't have a PCV valve initially (I'll admit I didn't fully understand the system at the time). So it would have had a fresh air line to the back intake port from the air cleaner base, then other port to the can and from the can to the throttle body base plate. Latest setup just added a PCV valve between the intake and can.
Jumped on the throttle the other day and saw oil pressure drop. Checked the dipstick and it was low. Changed the oil and only pulled ~3.5 and change quarts out of what is likely closer to a 6 quart system. Catch can was totally full. The tough part is trying to piece together the timeline as until recently the car was only driven sporadically, so not sure when I put the PCV in relative to the last oil change. I know my catch can was garbage, so that doesn't help, but still not sure how it filled the whole thing up.
Did a little playing around on it yesterday and found that the idle vacuum with the base plate port fully plugged is similar to the vacuum with the PCV plugged in and open to air (crankcase end of the valve not connected), so I think the valve is working correctly. I got rid of my catch can for the time being because I know it's not designed right. So at this point I think my system is "functional", but guess I won't know for sure until I put more miles on it to see if it uses as much oil. Strange part is that through all of this the car never seemed to smoke or smell like burning oil, despite me seeing oil puddles on the backs of valves when I took the intake off a while back.
To give some context, when I first did the engine swap I just ran a breather on one of the intake ports and plugged the other. It worked, but it was always messy around the breather. I later decided to put in a DIY catch can (a stainless steel water bottle with some fittings screwed in and steel wool stuffed inside), but still didn't have a PCV valve initially (I'll admit I didn't fully understand the system at the time). So it would have had a fresh air line to the back intake port from the air cleaner base, then other port to the can and from the can to the throttle body base plate. Latest setup just added a PCV valve between the intake and can.
Jumped on the throttle the other day and saw oil pressure drop. Checked the dipstick and it was low. Changed the oil and only pulled ~3.5 and change quarts out of what is likely closer to a 6 quart system. Catch can was totally full. The tough part is trying to piece together the timeline as until recently the car was only driven sporadically, so not sure when I put the PCV in relative to the last oil change. I know my catch can was garbage, so that doesn't help, but still not sure how it filled the whole thing up.
Did a little playing around on it yesterday and found that the idle vacuum with the base plate port fully plugged is similar to the vacuum with the PCV plugged in and open to air (crankcase end of the valve not connected), so I think the valve is working correctly. I got rid of my catch can for the time being because I know it's not designed right. So at this point I think my system is "functional", but guess I won't know for sure until I put more miles on it to see if it uses as much oil. Strange part is that through all of this the car never seemed to smoke or smell like burning oil, despite me seeing oil puddles on the backs of valves when I took the intake off a while back.
The PCV valve can be located anywhere in an appropriately sized manifold vacuum hose. You can even put it IN the hose itself. As long as one end has manifold vacuum and the other is in the crankcase, you're good.
When I first did mine I ran a straight valve from the port to the back of the intake elbow (I use an elbow to mount an oval tb facing forward)it sucked so much oil it saturated the base gasket and started weeping at the seam. Now,maybe a half pint in 2 years. The prefix intake was available with a fill Tobe that uses a stock 6.1 oil cap. Breathers.com had a replacement cap with a replaceable element on top
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