exhaust system pcv?

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j par

j par

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Bought the jegs kit - two breathers and two weld-in one way valves [ ATTACH ] 1714774828 [ / ATTACH ] the instructions say to install towards the end of the headers? But I have 3 " collectors into 2 1/2 pipes into 2 1/2 cherry bombs into 2 1/2 pipes out the side. I'm wondering if it would be better to put it in the two and a half inch pipe instead of the 3 inch collector maybe before or after the cherry bombs to avoid any back pressure?View attachment 20141210_215325.jpg

View attachment 20140423_145054-1.jpg
I know there's a lot of guys that use the system I've seen it at the drag strip I just am not sure exactly where to put the one way valve?
 
j par said:
Bought the jegs kit - two breathers and two weld-in one way valves [ ATTACH ] 1714774828 [ / ATTACH ] the instructions say to install towards the end of the headers? But I have 3 " collectors into 2 1/2 pipes into 2 1/2 cherry bombs into 2 1/2 pipes out the side. I'm wondering if it would be better to put it in the two and a half inch pipe instead of the 3 inch collector maybe before or after the cherry bombs to avoid any back pressure?View attachment 1714774834

View attachment 1714774835
I know there's a lot of guys that use the system I've seen it at the drag strip I just am not sure exactly where to put the one way valve?
Click to expand...

you must have a very low restriction exhaust system to realize any benefit from the evac system. I don` think it`ll work on your set up --jmo
 
I have that same setup; I installed mine in the collector on a set of Dougs D450 headers. I have always found that you would need to install them IN the collector. I am running Borla mufflers dumped at the axle, and an X pipe, all mandrel bent 2 ½ system. At idle, there was a MASSIVE vacuum on the hose going to the valve cover. As I would increase throttle, the system would stop sucking, and blow backwards. I attribute this to having a slightly “restrictive” exhaust. I do not use the system anymore because it is really meant to be for a very free flowing exhaust. When I run my car open header, it works GREAT. Just my 2 cents worth.
 
:idea1:What about the idea of after the cherry bombs? Or in other words- after any restrictions?
 
It will work fine depending on how the angle cut end of the tube is installed in the pipe.
There are 3 different ways it can be installed, and each way will give different results.
Some people say there is only one right way, but then get no vacuum doing it that way.

Going into the pipe at an approximate 45 degree angle and having the longest part of the end of the crosscut toward the engine will give the most vacuum.
Of course doing it this way could cause so much vacuum as to actually start sucking oil mist out of the engine and causing it to smoke.

Then there is RPM's to consider.
Do you want this to only have a good vacuum at idle, or higher R's?

My advice would be to make your hole for the tube and experiment with the angle and direction of the valve tube end until you get what you want.
Then weld it up.
You may even consider a ball valve in the rubber tubing on each side so you can limit the vacuum volume (especially if you put it in the way I described above, as that way creates the highest vacuum)

I can draw the different ways of installing it for you if you would like, and describe why each install gives different results.

In all three scenarios I would put it at least a few inches after the collector and before the glasspacks.
The highest speed of the exhaust gasses is acheived right after it necks down to the 2.5 pipe.

Of course there are other oppinions on all of this. :)
 

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I want to know (I really do, not being sarcastic) why I'll see a high 11 second car have his pcv in the exhaust, and I'll see a low 10 second car run his off the valve cover?
 
318willrun said:
I want to know (I really do, not being sarcastic) why I'll see a high 11 second car have his pcv in the exhaust, and I'll see a low 10 second car run his off the valve cover?
Click to expand...

Because the guy with the vac in the exhaust was paying more attention to the cool looking stuff, and the guy with it in the valve cover put his resources to being faster. :)

Heck I don't know.
 
I put a set of those in my TTIs. They worked too good at higher rpms. Clouds of smoke while auto crossing too.I had to restrict them and modify the baffles in the vc. Eventually I took them off.
 
I run those in my collectors and I have Dynomax Bullet mufflers. Before I started using them some oil would come out of my breathers while I was going done the track and get on my headers. I was not running a pcv valve. I do not want oily air going in my intake.
I have only installed one so far and it stopped the problem, I may not ever put the other one on.
 
TrailBeast said:
It will work fine depending on how the angle cut end of the tube is installed in the pipe.
There are 3 different ways it can be installed, and each way will give different results.
Some people say there is only one right way, but then get no vacuum doing it that way.

Going into the pipe at an approximate 45 degree angle and having the longest part of the end of the crosscut toward the engine will give the most vacuum.
Of course doing it this way could cause so much vacuum as to actually start sucking oil mist out of the engine and causing it to smoke.

Then there is RPM's to consider.
Do you want this to only have a good vacuum at idle, or higher R's?

My advice would be to make your hole for the tube and experiment with the angle and direction of the valve tube end until you get what you want.
Then weld it up.
You may even consider a ball valve in the rubber tubing on each side so you can limit the vacuum volume (especially if you put it in the way I described above, as that way creates the highest vacuum)

I can draw the different ways of installing it for you if you would like, and describe why each install gives different results.

In all three scenarios I would put it at least a few inches after the collector and before the glasspacks.
The highest speed of the exhaust gasses is acheived right after it necks down to the 2.5 pipe.

it says in the instruction to install it in the manner of the most vacuum. Like in the last picture you showed. I guess this is part of my question to: is when will I need the vacuum to be the most? of course you know the build of the motor and I'll be driving it around a little bit to show friends and a couple of watch this moments or danger rides as I like to call them and probably half of its life or more on the drag strip. The car is for all intensive purposes a drag strip car but, it is street legal and I'll probably be driving it to the track and back hopefully back! Lol
Click to expand...
 
D-50394 said:
I run those in my collectors and I have Dynomax Bullet mufflers. Before I started using them some oil would come out of my breathers while I was going done the track and get on my headers. I was not running a pcv valve. I do not want oily air going in my intake.
I have only installed one so far and it stopped the problem, I may not ever put the other one on.
Click to expand...
see this is exactly my same problem. I had breathers- three of them and one filler cap. oil is going all over my valve covers. & I didn't want to run oily air into my intake so this could be the compromise to only use one and not both?
 
AJ/FormS said:
I put a set of those in my TTIs. They worked too good at higher rpms. Clouds of smoke while auto crossing too.I had to restrict them and modify the baffles in the vc. Eventually I took them off.
Click to expand...

I'm thinking maybe it was the whole autocrossing thing? I'm sure my car will be on as smooth as roads as possible and hopefully in a straight line as most mopars iv owned don't like to go around CORNERS . LOL
 
318willrun said:
I want to know (I really do, not being sarcastic) why I'll see a high 11 second car have his pcv in the exhaust, and I'll see a low 10 second car run his off the valve cover?
Click to expand...
I'd really like to know that trick and how you answer everybody's post all in one post? So for now I'll just have to answer individually.
I'm a little confused on this question straighten me out please? I would be using the vacuum from the exhaust to pcv through the valve cover?I know you weren't being sarcastic but I'm having trouble and it's probably just me understanding the question?
 
j par said:
see this is exactly my same problem. I had breathers- three of them and one filler cap. oil is going all over my valve covers. & I didn't want to run oily air into my intake so this could be the compromise to only use one and not both?
Click to expand...

You could start with one and a breather on the other side of the engine at first and see how it does.
The PCV is normally for low/mid RPM, so I would put it in like they say, and then be ready to limit the vacuum volume in case even one pulls too much.
A ball valve in the rubber line to the engine, or even a restricting orifice works for this.

Keep in mind that if you end up using both of them that you will still need a fresh air inlet.
I like to do this at the air cleaner so the fresh air inlet is filtered air.

This how I did mine for filtered fresh air.
I used a brass fitting with a small ring of PEX tubing (because I had it laying around) on the fitting first and then put the elbow through the base of my air cleaner, and another ring of the PEX and crimped it with a copper ring.
The tied wire is insurance against it slipping off and falling down the carb throat. (just drilled it and tied it)

It worked great because when I crimped the ring on it spread the PEX and sealed nice and tight to the air cleaner base, but still able to swivel for installation.
 

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TrailBeast said:
You could start with one and a breather on the other side of the engine at first and see how it does.
The PCV is normally for low/mid RPM, so I would put it in like they say, and then be ready to limit the vacuum volume in case even one pulls too much.
A ball valve in the rubber line to the engine, or even a restricting orifice works for this.

Keep in mind that if you end up using both of them that you will still need a fresh air inlet.
I like to do this at the air cleaner so the fresh air inlet is filtered air.

This how I did mine for filtered fresh air.
I used a brass fitting with a small ring of PEX tubing (because I had it laying around) on the fitting first and then put the elbow through the base of my air cleaner, and another ring of the PEX and crimped it with a copper ring.
The tied wire is insurance against it slipping off and falling down the carb throat. (just drilled it and tied it)

It worked great because when I crimped the ring on it spread the PEX and sealed nice and tight to the air cleaner base, but still able to swivel for installation.
Click to expand...
first I better shoot you a picture of my carburetors & filter-View attachment 20140630_175154-1.jpg
I was thinking a valve cover breather on one side and the pcv on the other side?
 
Just get a couple nice K&N filtered breathers and forget about all the pcv stuff. IMHO it isn't needed. Others will disagree.

One thing you said was that there is oil all over your valve covers. Are there baffles under every breather? You'll also want a baffle under the pcv valve if you decide to run one.
 
TrailBeast said:
It will work fine depending on how the angle cut end of the tube is installed in the pipe.
There are 3 different ways it can be installed, and each way will give different results.
Some people say there is only one right way, but then get no vacuum doing it that way.

Going into the pipe at an approximate 45 degree angle and having the longest part of the end of the crosscut toward the engine will give the most vacuum.
Of course doing it this way could cause so much vacuum as to actually start sucking oil mist out of the engine and causing it to smoke.

Then there is RPM's to consider.
Do you want this to only have a good vacuum at idle, or higher R's?

My advice would be to make your hole for the tube and experiment with the angle and direction of the valve tube end until you get what you want.
Then weld it up.
You may even consider a ball valve in the rubber tubing on each side so you can limit the vacuum volume (especially if you put it in the way I described above, as that way creates the highest vacuum)

I can draw the different ways of installing it for you if you would like, and describe why each install gives different results.

In all three scenarios I would put it at least a few inches after the collector and before the glasspacks.
The highest speed of the exhaust gasses is acheived right after it necks down to the 2.5 pipe.

Of course there are other oppinions on all of this. :)
Click to expand...

For the system to create a vacuum, the tubes must be facing rearward. The last diagram with the tubes facing forward, it would force exhaust pressure up through the hoses and create a positive pressure in the crankcase. tmm
 
toolmanmike said:
For the systeis create a vacuum, the tubes must be facing rearward. The last diagram with the tubes facing forward, it would force exhaust pressure up through the hoses and create a positive pressure in the crankcase. tmm
Click to expand...

I think on all of the diagrams the exhaust is moving right to left.
 
toolmanmike said:
For the system to create a vacuum, the tubes must be facing rearward. The last diagram with the tubes facing forward, it would force exhaust pressure up through the hoses and create a positive pressure in the crankcase. tmm
Click to expand...
the valves are one way, the pressure cannot get back up the evac tubes
 
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