72 Dart 360 PVC valve issues

-
B

Brandenthepilot

Member
Joined
Mar 24, 2025
Messages
19
Reaction score
6
Location
Chicago
Wondering if anyone can guide me on the proper set up here. Yesterday start having smoking (or steam?) coming from the oil breather you can see it in the video.

The PVC valve is on the driver side cover, when I pulled the valve and only stuck the hose back into the grommet the smoke stopped and seemed to run fine. I put the valve back on and the issue started again. Ran to the store and picked up a brand new valve, and the same Issue persisted.

The current set up if you cant make it out in the pictures, is just an air cleaner, the PVC valve is on the drivers side which the hose runs to the passenger side of the carburetor.
If you have a more efficient set up please let me know. Or if there’s a better pvc valve to use than just the basic plastic one. Thank you

image1.jpg


image2.jpg


image3.jpg
 
I see you have what appears to be a mopar electronic ignition with a hotter coil and possibly no ballast resistor.

Too much advance on the timing can do funny things to your crankcase pressure and the the pcv valve.

Back your timing down 4 degrees. and see if that 100% cures your problem.

Report back, then we can talk about what wide plug gaps can do to your timing with an other than stock ignition system.

If by chance you are running 18 degrees BTDC (advanced) along with the faster burning hotter spark, it's going to be too much timing and you need to back it down so that fireball is exploding in the combustion chamber at just the right time for your layout.


76 LA 843890.jpg




* * * * *
 
George Jets said:
I see you have what appears to be a mopar electronic ignition with a hotter coil and possibly no ballast resistor.

Too much advance on the timing can do funny things to your crankcase pressure and the the pcv valve.

Back your timing down 4 degrees. and see if that 100% cures your problem.

Report back, then we can talk about what wide plug gaps can do to your timing with an other than stock ignition system.

If by chance you are running 18 degrees BTDC (advanced) along with the faster burning hotter spark, it's going to be too much timing and you need to back it down so that fireball is exploding in the combustion chamber at just the right time for your layout.


View attachment 1716383578



* * * * *
Click to expand...
thank you for that info! I havent worked much on this car its been in storage for years. and honestly just started having an interested in the Mopar stuff. Is that ignition something you'd recommend purchasing?
 
Brandenthepilot said:
thank you for that info! I havent worked much on this car its been in storage for years. and honestly just started having an interested in the Mopar stuff. Is that ignition something you'd recommend purchasing?
Click to expand...

Your existing ignition is probably fine. I see they added that red coil over on the passenger inner fender, so that tells me someone has been in there doing things with the ignition system.

You might want to have someone in the know look over your ignition system to see just what you have.

Stock systems have a ballast resistor, I don't see that, and a thin Mopar Brain Box and I don't see that but it does look like a mopar electronic distributor.

If it starts and runs right now that's a good first step.


☆☆☆☆☆
 
George Jets said:
Your existing ignition is probably fine. I see they added that red coil over on the passenger inner fender, so that tells me someone has been in there doing things with the ignition system.

You might want to have someone in the know look over your ignition system to see just what you have.

Stock systems have a ballast resistor, I don't see that, and a thin Mopar Brain Box and I don't see that but it does look like a mopar electronic distributor.

If it starts and runs right now that's a good first step.


☆☆☆☆☆
Click to expand...
Tried attaching a video but cant. It does start and run with no issues, the smoking issue start after about 5 or 6 days of driving it around to feel everything out. Not sure if it was just time of pressure building at the crank or not. I'll try to get it in front of someone that can tell me more about it.
 
Take the oil fill cap off while it is running and put your hand over the hole to see if there is pressure building there.

Don't want a lot of pressure there or it can start pushing oil out the rear main, and that's no fun to fix.


☆☆☆☆☆
 
George Jets said:
I see you have what appears to be a mopar electronic ignition with a hotter coil and possibly no ballast resistor.

Too much advance on the timing can do funny things to your crankcase pressure and the the pcv valve.

Back your timing down 4 degrees. and see if that 100% cures your problem.

Report back, then we can talk about what wide plug gaps can do to your timing with an other than stock ignition system.

If by chance you are running 18 degrees BTDC (advanced) along with the faster burning hotter spark, it's going to be too much timing and you need to back it down so that fireball is exploding in the combustion chamber at just the right time for your layout.


View attachment 1716383578



* * * * *
Click to expand...
It's running off a MSD system.
 
And just a side note, fix that throttle return spring that's arched around and stuck into that other throttle return spring... LOL
1742854058614.png
 
Now that @318willrun mentioned it, it is running on an MSD Ignition Box, shown in the lower left of this picture, along with the red MSD tower coil.

Red Ignition Box.png


Aftermarket ignition components, not a stock setup.


* * * * *
 
Brandenthepilot said:
Lmao! I didn’t even notice that haha

so could the timing be an issue as @Georgejets said?
Click to expand...
From what you described....
  • I wonder what kind of vacuum you have coming from the carb on the side?
  • Is the hose too big for the PVC valve fitting and leaking around it? Try a hose clamp to see if that helps
  • I mean, we could be talking blow-by
 
Put a timing light on #1 and see if is flashing anywhere near top dead center TDC > Should be like 12-16 degrees advanced, when you point it at the harmonic balancer behind the lower front pullies.
 
318willrun said:
From what you described....
  • I wonder what kind of vacuum you have coming from the carb on the side?
  • Is the hose too big for the PVC valve fitting and leaking around it? Try a hose clamp to see if that helps
  • I mean, we could be talking blow-by
Click to expand...
Lets not bring up Blow-by just yet lol.

I'll get a clamp tomorrow and see what happens. Like i said when i take the valve off and stick just the hose end (i know its not a good thing) it stops.But with the valve in it doesnt do much of anything. Is there a after market valve that might be better to use than just the plastic ones?
 
Brandenthepilot said:
Lets not bring up Blow-by just yet lol.

I'll get a clamp tomorrow and see what happens. Like i said when i take the valve off and stick just the hose end (i know its not a good thing) it stops.But with the valve in it doesnt do much of anything. Is there a after market valve that might be better to use than just the plastic ones?
Click to expand...
there are metal ones... but usually the plastic work ok too
 
George Jets said:
Put a timing light on #1 and see if is flashing anywhere near top dead center TDC > Should be like 12-16 degrees advanced, when you point it at the harmonic balancer behind the lower front pullies.
Click to expand...
I'll grab a gun tomorrow and see what it's reading. Where do you think it should be running? or is the completely unique to each engine/set up.
 
Brandenthepilot said:
I'll grab a gun tomorrow and see what it's reading. Where do you think it should be running? or is the completely unique to each engine/set up.
Click to expand...
each engine will like its own timing. Is there an aftermarket cam in it??? Stock or built?? Could idle anywhere between 8*-20* ... to be honest I've gone all over the place with timing all over my years all over my many cars and not have what you are experiencing happen
 
318willrun said:
each engine will like its own timing. Is there an aftermarket cam in it??? Stock or built?? Could idle anywhere between 8*-20* ... to be honest I've gone all over the place with timing all over my years all over my many cars and not have what you are experiencing happen
Click to expand...
I dont know much about the car. Dad bought it about 5 years ago, it sat in a garage basically the whole time. I just moved back from florida in novemeber so its my "summer car" for the time being and just trying to get it running right. I want to say it was built to a 408.
 
To read the timing correctly you need to pull the vacuum advance hose off at the carb and plug that carb port with a short hose and a golf tee.

Also slow the idle way down so the mechanical advance is not engaging.

Should be somewhere around 12 degrees BTDC advanced initial and 30° degrees maximum when it's reved up to 2500 rpm.

If it's got a big cam in it, it won't idle very well as they turn on over 1500 rpm.

Pull one plug and see what it's gapped at, .035 ths or .050 ths. If its .050 ths this can make an additional 4 degrees advance as to what the timing light is telling you because of the wider longer plug spark burning the air/ fuel faster.

It makes a difference, and it's easy to get too much advance causing problems you don't need.

A white chalk mark on the TDC groove in the front balancer will make it easier to read with the timing light.

Marking where TDC is on the timing cover helps also.

The dial back timing lights work nice, as you can dial back the timing so it shows TDC on the balancer, then you read how many degrees BTDC it is showing on the dial pointer.

Easier than trying to read the BTDC degrees down on the timing cover.

☆☆☆☆☆
 
Last edited:
Ign timing is not going to change, or stop, fumes exiting the breather unless the ign timing provides a large change in idle rpm. This is not an ign problem.
It sounds like the engine is worn & you are getting more crankcase blowby, which shows up as fumes exiting the breather.
At idle, the PCV is only able to suck in a small amount of the fumes, & the rest shows up as fumes at the breather. By eliminating the PCV & putting the PCV hose directly into the grommet, you will suck out a lot more fumes & less fumes will be seen exiting the breather.

Even though the engine is worn, it can run ok for years to come but might be down some on power, foul spark plugs etc.
 
I’ve yet to see where is the pcv hose is going to? Carb or intake manifold port.

Not sure of Brandan’s skill level. So far it seems knowledgeable. I’d be less concerned about blow by if the engine is starting well and runs well. Ignition timing is a bit more advanced of a skill for most people- not commenting on the Actual ignition timing.

As for the PCV- I’d prefer to see a mopar PCV unit on there vs an auto parts store one hanging from advanced auto. But honestly if there is one on there that is a good thing. There are high cost adjustable pcv units available.
If the car is not consuming oil at an alarming rate…. 1 to 1-1/2 quarts per 3000miles, I’m also not alarmed. (That statement will bring controversy I’m sure- it’s a guide line…. That’s all)
 
Syleng1 said:
I’ve yet to see where is the pcv hose is going to? Carb or intake manifold port.

Not sure of Brandan’s skill level. So far it seems knowledgeable. I’d be less concerned about blow by if the engine is starting well and runs well. Ignition timing is a bit more advanced of a skill for most people- not commenting on the Actual ignition timing.

As for the PCV- I’d prefer to see a mopar PCV unit on there vs an auto parts store one hanging from advanced auto. But honestly if there is one on there that is a good thing. There are high cost adjustable pcv units available.
If the car is not consuming oil at an alarming rate…. 1 to 1-1/2 quarts per 3000miles, I’m also not alarmed. (That statement will bring controversy I’m sure- it’s a guide line…. That’s all)
Click to expand...
I work on airplanes and an LT1 out of my 97 fire bird was about the latest engine ive ever touched. lol I have a decent understanding of engines, but yes i have never worked on timing, I've used a local shop for all of that but right now they kind of seem to be refusing to touch this car. Not sure why.

Not sure why i said carburator, it runs to the passenger side of the intake. Sorry about that.
 
Bewy said:
Ign timing is not going to change, or stop, fumes exiting the breather unless the ign timing provides a large change in idle rpm. This is not an ign problem.
It sounds like the engine is worn & you are getting more crankcase blowby, which shows up as fumes exiting the breather.
At idle, the PCV is only able to suck in a small amount of the fumes, & the rest shows up as fumes at the breather. By eliminating the PCV & putting the PCV hose directly into the grommet, you will suck out a lot more fumes & less fumes will be seen exiting the breather.

Even though the engine is worn, it can run ok for years to come but might be down some on power, foul spark plugs etc.
Click to expand...
Man, I'd really like to see the car running at it's best. Wanted to avoid a rebuild but if it calls for that then I'm willing to do it.
 
You must log in or register to reply here.
-

Back
Top