Foxy Green Foxbody Build

I tell you what. The internet and AI don't know what the fuck a pcv valve does and now neither do I.

It talks about high rpm and low rpm but I thought rpm doesn't have fuck all to do with it.

Isn't it vacuum and not rpm?

I don't care if the pcv is open at 900rpm and 9" vacuum but it better be closed at 1800rpm with 20" vacuum or my car is going to go lean again
 
PCV valves let your engine do a couple of things, some are useful, some are not. They do help stop the build-up of moisture in your crankcase by letting the engine pull a vacuum in there. But if you get the engine up to temp it doesn't matter. But while doing this you are pulling-in vapors containing oil. What does that do? Coats shit with oil AND lowers your octane rating of your fuel.............

A good breather on each valve cover and don't start/stop the engine all the time and let it get warm, you will have no problems.
 
Mike Beck said:
PCV valves let your engine do a couple of things, some are useful, some are not. They do help stop the build-up of moisture in your crankcase by letting the engine pull a vacuum in there. But if you get the engine up to temp it doesn't matter. But while doing this you are pulling-in vapors containing oil. What does that do? Coats shit with oil AND lowers your octane rating of your fuel.............

A good breather on each valve cover and don't start/stop the engine all the time and let it get warm, you will have no problems.
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I've have a rear main leak that disappeared with vacuum on the engine. In not the only one this happened to so I'd like to run one.

My pcv would be run through a catch can/ oil separator
 
Rear main seals are under full oil pressure, if they are going to leak, they are going to LEAK! Been there done that. Now crankcase leaks, they are another story. Like oil pan, valve covers, timing cover, distributor, etc............

If you use a PCV valve then plumb it through a catch can. That will help capture the oil mist. One valve cover will be pulling vacuum via the PCV valve. the other one will have a breather in it. That cover usually gets plumbed to clean air after the air filter. or just use a breather.
 
Mike Beck said:
One valve cover will be pulling vacuum via the PCV valve. the other one will have a breather in it. That cover usually gets plumbed to clean air after the air filter. or just use a breather.
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On a street SBC I ran a stock PCV hose to the OE fitting on the intake manifold from one valve cover. The engine originally had a hose with a spark arrestor in it from the air cleaner as Mike described to the other valve cover. I Used a different air cleaner so I just plugged that cover. Engine eventually developed a squeak in the timing cover seal at idle under full vacuum. So I replaced the plug with a small K&N filter that fit the hole. 100K miles, zero trouble.
I say the PCV is just a self adjusting contolled air leak. The spring opens it up under low vacuum conditions to allow air to flow out of the crankcase. The increased airflow caused by higher intake manifold vacuum pulls the valve closed against the spring to meter the airflow down close to where it was under low vacuum condition so it doesn't lean out the mix in the intake manifold dramatically. If you pull the PCV out of the valve cover while the engine is idling you'll hear there is only a small amount of air flowing through it. If you think it's causing mixture problems, disconnect it until you solve that. A PCV is not required for proper engine operation. It was invented to replace draft tubes to keep the roadway drier and the engine cleaner by burning the oil vapor instead of just allowing it to leak out wherever.
I've run vac-u-pan extractors into the headers on street cars with zero problems, and so have my friends.
 
89 Fox 427 said:
I tell you what. The internet and AI don't know what the fuck a pcv valve does and now neither do I.

It talks about high rpm and low rpm but I thought rpm doesn't have fuck all to do with it.

Isn't it vacuum and not rpm?

I don't care if the pcv is open at 900rpm and 9" vacuum but it better be closed at 1800rpm with 20" vacuum or my car is going to go lean again
Click to expand...

They're retarded, how would a doohickey hooked up to your valve cover sense RPM?

The orifice of a PCV is less than .100, it's not going to lean your motor like an open hose.

Here's a PCV article:

 
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If you want to keep the vacuum but not sure about having a PCV, another option is to do what I've done and make an inline restrictor to turn it into a calibrated leak. Mine has a barb at each end and takes a Holley bleed jet. The bleed jet is the calibrated leak and the idea was I could change it if needed. From memory I started with a 75 and have never needed to change it.
 
hq308 said:
If you want to keep the vacuum but not sure about having a PCV, another option is to do what I've done and make an inline restrictor to turn it into a calibrated leak. Mine has a barb at each end and takes a Holley bleed jet. The bleed jet is the calibrated leak and the idea was I could change it if needed. From memory I started with a 75 and have never needed to change it.
Click to expand...

Now you're speaking my language.
Fabrication ✅️
Adjustability ✅️
Cool story ✅️
Functional ✅️
More time and effort vs simple ✅️

Got any pics?

I would need to adapt a 3/8 ID hose to 10-32 bleed screw back to 3/8 ID hose

Really fuck it off and use a fuel regulator with a vacuum gauge on it and adjust to the percentage of leakage I want.

Use a shark bite fitting with ball valve like it's a cold water line for a sink and close it as much as needed.

Maybe they make some kind of valve that closes under vacuum 🤣🤣
 
I haven't got any photos handy but it is basically just a double end barb with one barb tapped to take a Holley bleed jet. Bleed jet is smaller than the hose ID from memory. You could also get some 10-32 set screws and some number drills instead of the expensive Holley jets.
 
89 Fox 427 said:
Now you're speaking my language.
Fabrication ✅️
Adjustability ✅️
Cool story ✅️
Functional ✅️
More time and effort vs simple ✅️

Got any pics?

I would need to adapt a 3/8 ID hose to 10-32 bleed screw back to 3/8 ID hose

Really fuck it off and use a fuel regulator with a vacuum gauge on it and adjust to the percentage of leakage I want.

Use a shark bite fitting with ball valve like it's a cold water line for a sink and close it as much as needed.

Maybe they make some kind of valve that closes under vacuum 🤣🤣
Click to expand...
Now this sounds like some down south Yankee ingenuity
 
ResurrectionJoe said:
Install one of these off each valve cover to the firewall mounted as high as possible and then shove your pcv valve or whatever dumb shit you have hooked to your carb contaminating your fuel charge with oil misted air up your ass where it belongs.

Click to expand...

You could try to be a little more romantic about it.

But you forgot the sucky sucky part of the equation
 
Yoyodyne said:
Yeah, yeah, that's the ticket! Maybe you could make them and sell them!
Click to expand...

Seriously though if they'd make a 3/8 barb to 3/8 barb pcv that was fairly inexpensive that would be nice.

Due to the already drilled valve cover I'd prefer to run it on the other side of the catch can so no junk clogs it up.

I found 10an ORB to 3/8 barb that's about as close as I can get to being plug and play with my junk
 
89 Fox 427 said:
Now you're speaking my language.
Fabrication ✅️
Adjustability ✅️
Cool story ✅️
Functional ✅️
More time and effort vs simple ✅️

Got any pics?

I would need to adapt a 3/8 ID hose to 10-32 bleed screw back to 3/8 ID hose

Really fuck it off and use a fuel regulator with a vacuum gauge on it and adjust to the percentage of leakage I want.

Use a shark bite fitting with ball valve like it's a cold water line for a sink and close it as much as needed.

Maybe they make some kind of valve that closes under vacuum 🤣🤣
Click to expand...
Isuzu, Honda, inline types but not sure of hose sizes.
 
hq308 said:
I haven't got any photos handy but it is basically just a double end barb with one barb tapped to take a Holley bleed jet. Bleed jet is smaller than the hose ID from memory. You could also get some 10-32 set screws and some number drills instead of the expensive Holley jets.
Click to expand...

A Holley jet screws right into the inside of a -6 AN fitting.
 
89 Fox 427 said:
Seriously though if they'd make a 3/8 barb to 3/8 barb pcv that was fairly inexpensive that would be nice.
Click to expand...
97132


$7.49 at NAPA. Cheap enough?


But whatever you do, don't connect it backwards, or you'll explode your nitrous bottle and your interior courtesy lights will violently burn out.
 
I put a glass fuel filter in my pcv hose because all the Pontiac guys said the hole/pcv was in the wrong place and was going to suck oil. Its in the valve cover not the valley pan per factory. Been there for 3yrs or better and you can see a SMALL amount of oil trapped in the filter. A pcv just doesn’t seem to be the oil sucker that everyone makes it out to be
Just my experience
 
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