Generation IV Internal Engine - HELP, 418 has to much crankcase pressure, blowing out everywher!!!!

ok i got a 418 ls3, and when you get on it and get the rpms high this thing builds up so much crankcase pressure it was blowing the oil dipstick out and shooting oil every where, we added a catch can and zip died the dipstick down and everything seemed fine until one time I got on it and saw all kinds of smoke out the back, got the car on a lift and looked like it blew oil out the back of the main seal (i dont think it damaged it) so then we added a breather, things seem to be ok from there but then after about 500 miles of strait driving I noticed that oil was leaking out of the breather.

What is going on with this thing, i figure a catchcan and breather would stop excess crankcase pressure from doing this,

I really need help here i dont want my car shooting oil everywhere when I get on it.

You should not use a breather. How is your PCV system setup? If you do not have one, you should. I would do a compression test and see what you come up with there, then a cyl leakdown. I would do the tests cold first then hot. They should tell you everything you need to know.

i wouldnt think it would be bad rings, it did 508 on the dyno,
its not running a pvc system its running a catchcan. the driver side valve covor is running to the passenger side covor then the passenger side has a breather.

then the catchcan runs to the intake and the valley cover

Valley cover port goes to catch can, which goes to intake. I used two breathers on pass cover (One on oil cap, one on vent tube), one on driver cover (rear vent tube by firewall), and it finally stopped blowing oil (429 ls3). An alternative is a big boy valve cover setup with -10 or -12 vents to a catch tank, and a -10 or -12 off of the valley cover.


One breather on the VCs is not enough.

PS breathers only work when there is more pressure in the crank case than is outside the engine. At that point, the oil mist is already about to come out and the pressure has built to more than is acceptable.

There is never a need for breathers on a street driven car IMO. The low pressure system caused by a properly working PCV system will evac the crank case pressure. HMM maybe thats why its called a PCV system? Valley to intake, valve cover/s to the CAI.

But even if it did xxx HP on the dyno, using low tension oil rings and them being improperly setup can cause extreme oil consumption and excessive blowby.

ok so basicly leave the catchcan setup just like it is and attach breathers on everything else

I would not. I would build a proper pcv system that would tie the valve covers together and run into the cai. You can put a catch can on them also if you wish, but the factory valve covers have baffles which help cut down on the oil mist, but its still there.

I have aftermarket valve covers, is there a diagrahm out there for a proper pcv system for a ls3?

btw I think it was running a stock pvc system when it shot the dipstick out, then with the catchan system and then dipstick ziptied oil came out of the rear main seal, and now the breather, its going for the path of least resistence I guess, I got a buddy in town that should be real knowdegle about this and he runs a built 440 I will probably duplicate his setup and see what happens, if it dont fix it then I guess it could be bad rings and theres not much I can do about that.

Well there are a few ways to do it. Most people leave the driver side capped with that Gm rubber fitting and run off the pass side which has the tube running forward.

On yours, I would run a line from the driver cover around back and t into a line from the pass cover, then run them into the tube that should be going into the top of your TB.

Since you have aftermarket covers, they should have a small orifice in them, so there is no need for a pcv valve per se...

ok right now the driver side DOES run into the passenger side cover they are tied in together, NO T however, and the TB is capped off nothing runs to it

so basicly you are saying get T and then run to the TB and see what that does

Well that will help, but based on what you are saying, there is another cause for that pressure. But since it builds so much, you may want another catch can or a dual can setup like the rev kit that Colorado Speed sells. That would prob be most helpful and less clutter.

How big of a line do you have going too the catch can?

I run a single -12 to mine and it is enough.

Tim

everything is 3/8s

That is your problem.

Find a way to get a big line on it.

Tim

what difference does the line make when the metal tubes comming out of the intake and valve covers are tiny?

Don't use the tubes

Add a bigger fitting to the cover or valley plate and run a big line.

Weld in a -12

not sure if thats going to be possible anytime soon

I would not buy into any larger lines are better yet. Just get it going and see if it works better at least.

This thread has the answers to your routing question(s).

http://ls1tech.com/forums/11059703-post70.html

thanks for the info but from what I have looked up my routing is fairly ok and I should not have oil trying to come out of the breather, as much as I hate to say it i think the number one thing is a compression and leakdown test

PS breathers only work when there is more pressure in the crank case than is outside the engine. At that point, the oil mist is already about to come out and the pressure has built to more than is acceptable.

There is never a need for breathers on a street driven car IMO. The low pressure system caused by a properly working PCV system will evac the crank case pressure. HMM maybe thats why its called a PCV system? Valley to intake, valve cover/s to the CAI.

But even if it did xxx HP on the dyno, using low tension oil rings and them being improperly setup can cause extreme oil consumption and excessive blowby.

Obviously a stroker motor has excess crank pressure. :gay:

@ The op, add a breather on every tube (3 total), and run the PCV as I stated. Your problem WILL go away. It's what I had to do on MY big inch ls3, which has even more stroke then yours. I can add a picture if you like. Short of going to a big boy vent line (-12) it's your only option

^^^^^clown^^^^^ :jest:

That is what I'll be doing as well, hopefully tuning in 2 weeks.

sure show me a picture


Obviously a stroker motor has excess crank pressure. :gay:

@ The op, add a breather on every tube (3 total), and run the PCV as I stated. Your problem WILL go away. It's what I had to do on MY big inch ls3, which has even more stroke then yours. I can add a picture if you like. Short of going to a big boy vent line (-12) it's your only option

Maybe you are wrong Diet Coke. Well partly wrong. They may have some pressure, but I am dealing with a stroker as well in case you have not seen the thread......check out the 427 ceta in the dyno section. It has NONE of these problems and a properly operating PCV system. I can also say that the inside of his intake has NO oil filth inside of it. It has very little staining, but nothing of any residue.

It is NOT normal nor is it ok to live with any sort of pressure like what is A) going on in this thread B) what is normally experienced with most stroker apps.

well il find out in about 3 weeks, it obviously is burning oil because the oil light came on finally, even though I didnt notice any drop on the dipstick, It will be getting a compression and leak down test but first Im still going to race it and drive home on it next week, I figure if the rings are bad its not ganna affect anything by still driving it.

Oh yes it will and can cause other problems. I would scan it while you race to check for detonation. Remember, oil, esp at a mist, is combustible as well and it not accounted for in any sort of tuning parameters save for knock.....

I just ran my 408 for the first time and had a massive leak(s), looked to be coming out both ends. I have a single breather on the valley cover, but it's a 1 3/8" circle track style breather. The motor never had a drop of oil anywhere on it while on the run stand or after installing it in the car, but after running it at speed (5-7500rpm) the front of the motor and everything at the rear is covered. Would adding a second breather on the valley cover and a PCV line from a valve cover to the intake help my problem? For pics of my set-up check out the carburated section and the LS for circle track thread.

I believe by now that everyone knows my views on breathers. They will allow crankcase pressure to build until it is more than the pressure outside, then they will work in some sort of way......maybe.

Follow that link and run a proper PCV system and you should have no other problems after you fix the issues that are wrong now. Too much pressure can blow seals out enough to where they will not seat again.

If you still have too much pressure and do not want to set up a PCV system, then you may want to look into a crankcase evac system if your events will allow it. Last resort for me would be a downdraft tube/exhaust system tube or a breather.

I had the same problem with my LS2-402 after a few thousand miles.
My solution was a GZ Motor Sports VP101 Vacuum Pump.
The link below has a couple old pictures.
https://skydrive.live.com/redir.aspx?cid=1c63f3b4d3d1add7&resid=1C63F3B4D3D1ADD7!169&parid=1C63F3B4D3D1ADD7!168&authkey=!AM-VT4gM_NmalAI
I found the engine more responsive and better running after the installation. The pump pulls 6-12lbs. of vacuum and can pull more with a different size pulley.
Here's the link to GZ Motorsports. They have several LS kits.
http://www.gzmotorsports.com/

Good Luck!

Or you can do the whole AIR pump with the racetronix biz also. I have heard mixed results out of those though, but they are not mechanical rather electrical. Some guys use the wilwood vacuum pump or the CVR pump also as far as electrical, but the Racetronix wire kit comes with a hobbs switch so that it does not run all the time, just under certain conditions. Neat setup.

they also make a crank case evap kit that runs off exhaust presure and a check valve. it works by pulling all the presure out of the block.

http://www.ebay.com/itm/Moroso-25900-Crankcase-Evacuation-System-Steel-Gold-Iridited-Universal-Kit-/330712951780?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d00072be4&vxp=mtr

And into your exhaust where it will possibly put up a rather large cloud of smoke and/or contaminate your cats and O2 sensors, depending on where you put it. Those are so old, God used them on his hotrod, and I mentioned them earlier.

Maybe you are wrong Diet Coke. Well partly wrong. They may have some pressure, but I am dealing with a stroker as well in case you have not seen the thread......check out the 427 ceta in the dyno section. It has NONE of these problems and a properly operating PCV system. I can also say that the inside of his intake has NO oil filth inside of it. It has very little staining, but nothing of any residue.

It is NOT normal nor is it ok to live with any sort of pressure like what is A) going on in this thread B) what is normally experienced with most stroker apps.

Oil in the intake has little to nothing in common with crank pressure. His problem is caused by crankcase pressure, as was mine. Your results have little to do with it. As installed, the catch can on his car (and mine) is a pcv restriction, however it does keep oil vapor out of the intake, which necessitates breathers. Seeing as the case is ALWAYS going to try to equalize itself with ambient, you saying a breather is going to magically pressure an engine's internals is laughable. It's going to suck when it wants, and blow when it wants. Thats why they're called BREATHERS. Meanwhile the valley cover through a catch can still acts as positive vacuum evac.

Crank case pressure can sure cause alot more of that buildup in there. Excess pressure will blow the oil vapor into the intake if that is the PCV path. Otherwise it will vent to the atmosphere when the pressure inside the crank case is more than the pressure outside it is.

I installed some Mr Gasket "breathers" on my 88 GMC. Needless to say it is a worthless engine anyway, so there is no way I would ever be able to tell if it made it leak worse or not because like most GMs of its time, it marks it territory. They leave a nice oily film all over the valve covers.

Recently I saw what happens when a breather setup on the oil fill cap shoots oil out of it due to boost in the crankcase. It started to smoke and made a nice show. The oil FLOWED out of it. I know we are not talking about boost in this situation, but you get the point.

The results that this stroker has not a single problem with either excessive crankcase pressure like you say strokers do, and that it has no "normal" oil vapor problems in his intake say alot about a proper system.

If I have an opportunity, I will actually check the crankcase pressure at wot with a gauge with the setup that he has.

I guess if the OP still has problems after the breathers, then what?

... but first Im still going to race it and drive home on it next week, I figure if the rings are bad its not ganna affect anything by still driving it.
I had a customer that had a similar issue to what you're seeing. He ran his car with the dipstick mechanically secured in place, similar to what you've done, and from what i heard through the grapevine, he caught his car on fire. Apparently he blew a PCV line off a fitting and spewed oil on a hot motor, and poof.

I had a customer that had a similar issue to what you're seeing. He ran his car with the dipstick mechanically secured in place, similar to what you've done, and from what i heard through the grapevine, he caught his car on fire. Apparently he blew a PCV line off a fitting and spewed oil on a hot motor, and poof.

Similar to quite a few instances I have seen and heard of.

Crank case pressure can sure cause alot more of that buildup in there. Excess pressure will blow the oil vapor into the intake if that is the PCV path. Otherwise it will vent to the atmosphere when the pressure inside the crank case is more than the pressure outside it is.

I installed some Mr Gasket "breathers" on my 88 GMC. Needless to say it is a worthless engine anyway, so there is no way I would ever be able to tell if it made it leak worse or not because like most GMs of its time, it marks it territory. They leave a nice oily film all over the valve covers.

Recently I saw what happens when a breather setup on the oil fill cap shoots oil out of it due to boost in the crankcase. It started to smoke and made a nice show. The oil FLOWED out of it. I know we are not talking about boost in this situation, but you get the point.

The results that this stroker has not a single problem with either excessive crankcase pressure like you say strokers do, and that it has no "normal" oil vapor problems in his intake say alot about a proper system.

If I have an opportunity, I will actually check the crankcase pressure at wot with a gauge with the setup that he has.

I guess if the OP still has problems after the breathers, then what?

Then he needs to go to bigger breathers or have a -12 bung welded to his valley cover and run it to a -12 catch can.

At what point do you address the real problem? After waterhose size line takes over the engine bay?

There is nothing to address, you are simply delusional to the fact that a tight ring package WILL create excess crank pressure the necessitates a large PCV or breather setup on a large stroke ls3.

I refuse to accept that this is a problem inherent in these engines, esp when I have seen quite a few without this problem.

It should not be accepted nor should it be seen as the norm.

If this instance of spitting the dipstick tube out were on an SBC it would be laughed at and considered a wrong build, but on an LS engine its "nothing to be addressed"? Even with 5 breathers and water hose all over the intake, that should not be seen as acceptable for a street driven car.

On this part we can disagree, that way the argument is ended with both of us being right in our own minds.

I refuse to accept that this is a problem inherent in these engines, esp when I have seen quite a few without this problem.

It should not be accepted nor should it be seen as the norm.

If this instance of spitting the dipstick tube out were on an SBC it would be laughed at and considered a wrong build, but on an LS engine its "nothing to be addressed"? Even with 5 breathers and water hose all over the intake, that should not be seen as acceptable for a street driven car.

On this part we can disagree, that way the argument is ended with both of us being right in our own minds.

Whether you want it to be correct or not, breathers ARE the solution to his problem. Now go away.

^ sorry I will not bow down to you because your post count is higher. Ill stop arguing with you though because it is detracting from the thread now. And because you have no valid argument over what I say.

There is nothing to address, you are simply delusional to the fact that a tight ring package WILL create excess crank pressure the necessitates a large PCV or breather setup on a large stroke ls3.

A few finishing remarks.

BTW nice ninja edit. I totally missed that you added the entire part after There is nothing to address. I should have quoted you first.

Tight ring pack.....hmmm....whatever you say. I never said it would not make more pressure, I am saying the pressure that you quantify as normal is not normal.

What is the diff between your LS3 427 and the LS3 427 that I am currently working on? The main diff is, yours has some blowby or "excess pressure" issues that necessitate the need for breathers, and this one works with a standard 3/8 size PCV line. One from the valley to the intake and one from the pass cover to the TB. No catch can.

Please tell me what you mean by "tight ring pack" also. I am interested in this.

i have breathers on my 383 and its pushed oil out them since it was built idk either!

Ding Ding.

Op just try the breathers first and please let us know how it turns out.

82cetuner,
I would be curious as to what the short-block builder has to say about this. All too often it seems they pass the buck and put the blame somewhere else. IE.: Wrong oil, bad break-in, broken PCV, etc.

A few finishing remarks.

BTW nice ninja edit. I totally missed that you added the entire part after There is nothing to address. I should have quoted you first.

Tight ring pack.....hmmm....whatever you say. I never said it would not make more pressure, I am saying the pressure that you quantify as normal is not normal.

What is the diff between your LS3 427 and the LS3 427 that I am currently working on? The main diff is, yours has some blowby or "excess pressure" issues that necessitate the need for breathers, and this one works with a standard 3/8 size PCV line. One from the valley to the intake and one from the pass cover to the TB. No catch can.

Please tell me what you mean by "tight ring pack" also. I am interested in this.


The catch can off the valley cover restricts pcv,
The catch can off the valley cover restricts pcv
The catch can off the valley cover restricts pcv
The catch can off the valley cover restricts pcv
The catch can off the valley cover restricts pcv, did you not see me say that more then once already in this thread? My engine doesnt push any oil without a catch can, it does WITH a catch can. That is why I have to use breathers. :gay: Pay attention.

Also, there was no ninja edit, else it would have said post edited. WTG.

You can see all 3 3/8" breathers here. Additionally, a vented catch with a one way valve may assist with ventilation even farther.

http://i304.photobucket.com/albums/nn163/GhostRL/DSC04760.jpg

holy snap i just relized something the catchcan routing I have is OPPOSITE of yours in that picture the top tube on my catch can runs to the intake and the bottom tube runs to the vally cover, so is mine wrong?.

P.S. my breather sits at a angle, could it be possible its just mist hitting it then collecting and pooling then leaking out?.

on a side note though I think I am losing a descent amount of oil more than i would think normal. i belive quit a bit is comming out of the breather its not forcibly comming out or anything but just leaking down the breather

holy snap i just relized something the catchcan routing I have is OPPOSITE of yours in that picture the top tube on my catch can runs to the intake and the bottom tube runs to the vally cover, so is mine wrong?.

P.S. my breather sits at a angle, could it be possible its just mist hitting it then collecting and pooling then leaking out?.

on a side note though I think I am losing a descent amount of oil more than i would think normal. i belive quit a bit is comming out of the breather its not forcibly comming out or anything but just leaking down the breather

If your routing is opposite mine, then you would definitely be doing it wrong :cheers:. Swap the lines, that will help. The better (more) breathers you have, the less pressure each one sees individually, and the less likely you are to push oil. None of mine do.

The catch can off the valley cover restricts pcv,
The catch can off the valley cover restricts pcv
The catch can off the valley cover restricts pcv
The catch can off the valley cover restricts pcv
The catch can off the valley cover restricts pcv, did you not see me say that more then once already in this thread? My engine doesnt push any oil without a catch can, it does WITH a catch can. That is why I have to use breathers. :gay: Pay attention.

Also, there was no ninja edit, else it would have said post edited. WTG.

The orifice inside the valley cover restricts the pcv system if you want to call it like that. Its a metered orifice since GM no longer uses a valve for it. I am not sure what kind of restriction you think a catch can does, but ok.

Why dont you take the catch can off and run it normal instead of running a catch can and 3 breathers? Doesnt make much sense.

And I know what you put at the beginning of that post. It ended after the there is nothing to address. Now you go back and edit the rest of your posts. You only know the argument after the other side has given their rebuttal then you change it just a tad.

86 the breathers. They will cause you nothing but problems in your situation. If you are pushing oil out of them now, I have a feeling it will just get worse.

FYI if you are not careful you can pull unmetered air into your engine through the breathers too. This was brought up in another thread.

well wouldnt the air comming threw the catchcan also be unmetered and it goes directly into the intake, and its like that from factory.

I dont understand your statment how can air from the valve covers ever make it into the combustion chamber even if they are sucking air?? it would have to connect to the intake somehow like the catchcan does

well wouldnt the air comming threw the catchcan also be unmetered and it goes directly into the intake, and its like that from factory.

I dont understand your statment how can air from the valve covers ever make it into the combustion chamber even if they are sucking air?? it would have to connect to the intake somehow like the catchcan does

The short answer to that question is it doesn't, even though there is a LONG roundabout path to get to the CC by valve cover ----> lower end ---> valley ---> valley cover pcv ----> catch can ---> intake.

Catch can air is metered in a stock setup because the factory pcv draws air from behind the MAF, so the air has already been read and can be recycled indefinitely.

However due to pressure differentials inside the engine, the amount of air that does get in isn't measurable and does not effect AFR. Breathers (venting in general) are a good thing, gectek is mistaken.

Case in point, put a vacuum gauge on your intake manifold. Now take your oil fill cap off. Notice the vacuum doesn't change. Same concept applies to breathers, the air never makes it to the intake or combustion chamber, they simply allow excess pressure or vacuum in the lower end to bleed off.

im ganna swap the catchcan around and see if it still leakes if it does I will add a breather to the driver side valve tubing. my goal is to stop losing oil I dont really care how I do it as long as the compression test and leakdown test are ok.

Here is to hoping I dont have to do a rebuild!!!!!!!!

The higher flowing air inside your intake system actually creates a low pressure system that the higher pressure inside the engine is drawn to. The air does not push its way into your engine via the PCV system. That is how the PCV system draws excess crank pressure and oil vapors from your crankcase and into the intake stream for it to be reburned and relieved. Any air that is taken in by the PCV system is not accounted for in the standard VE calculations, that is why they have orifices on the valve covers and for the valley cover. So they can slow down the amount of transfer. This is how a downdraft or exhaust tube works also. The higher the pressure is, the faster it works.

You are mistaken on how a pcv system works in the first place. If you are running your engine at idle with the one pcv hose running from your pass valve cover to your TB and you take the cap off, you should notice some odd things. That is unless when the car was tuned you already had breathers on it. Then the airflow readings will be skewed in the wrong direction to try to take into account that unaccounted for air.

Let a newer dodge run then take the oil cap off it and see what happens.

You know how I know that? Because I did it.

Do not worry yourself Diet Coke, I will def test this whole theory out this coming week.

What I dont understand is that if your engine was running so good without a catch can, then why would you spend the extra money and cobble up your engine bay with a catch can then 3 breathers. Maybe there is something else you just arent saying.

The higher flowing air inside your intake system actually creates a low pressure system that the higher pressure inside the engine is drawn to. The air does not push its way into your engine via the PCV system. That is how the PCV system draws excess crank pressure and oil vapors from your crankcase and into the intake stream for it to be reburned and relieved. Any air that is taken in by the PCV system is not accounted for in the standard VE calculations, that is why they have orifices on the valve covers and for the valley cover. So they can slow down the amount of transfer. This is how a downdraft or exhaust tube works also. The higher the pressure is, the faster it works.

You are mistaken on how a pcv system works in the first place. If you are running your engine at idle with the one pcv hose running from your pass valve cover to your TB and you take the cap off, you should notice some odd things. That is unless when the car was tuned you already had breathers on it. Then the airflow readings will be skewed in the wrong direction to try to take into account that unaccounted for air.

Let a newer dodge run then take the oil cap off it and see what happens.

You know how I know that? Because I did it.

Do not worry yourself Diet Coke, I will def test this whole theory out this coming week.

What I dont understand is that if your engine was running so good without a catch can, then why would you spend the extra money and cobble up your engine bay with a catch can then 3 breathers. Maybe there is something else you just arent saying.


The catch can is to keep oil out of the intake.... the standard reason for using one. There is no hose from the VC to the intake tube. It got replaced with *gasp* a breather! I don't understand why this is so hard for you to comprehend

The setup I am talking about needs neither. Maybe its just a freak then. Or properly put together.....

This thread isnt about your engine. Surprise!

This thread isnt about your engine. Surprise!

Its not about yours either, and it not MY engine. Its one of my friends. No need to be mad and throw a fit. Ill lay off you for now.

The fact of the matte is, his car should still not be pushing oil through the breather that he has also. The air should be filtered either way and have the same restriction by routing it through a catch can from top out the side or in the side and out the top. Unless it has a check valve, which most do not.

OP how much oil does your catch can have in it after running it around for a day or so?

i havent even checked it yet bit i got about 1500 miles of interstate driving on the car

Hey look who is being a know it all dick... in this thread you do make some valid points but it looks like your know it all ego is getting in the way again.

The most effective way of pulling crank case pressure is using a vacuum pump and NOT recycling it into the intake stream. The oil will burn and will cause knock.

While the factory PCV does okay at best on a stock engine. It does a poor job once the cubic inches/piston speed increases, blow by from low tension or larger gapped rings and power adders. The factory has installed a PCV system due to emissions first and foremost and it does decrease crank case pressure to some degree. So it was a win win for the OEM.

Now ask your self why your PCV system is pushing oil. It is because the system isn't adequate and there is an airflow restriction. This is where breathers or a vacuum pump comes into play.

Now lets talk about this unmetered air you reference when running a breather. The engine will pull air from the path of least resistance. If it happens to be either through the PCV or the breather, it does not matter! It is all unmetered! I have tuned my fair share of LS vehicles and I have yet to see any noticeable changes in fueling error just by adding a breather.

Things can be simple and work... KISS- Keep It Simple Stupid. In all different motor sports from 2 stroke to 4 they run breathers... Why? Because it is simple and it works.

James like we talked about on the phone... Compression and leak down test. This will tell you where to look for your problem. While a breather can band-aid an issue. The real question what causing the problem to begin with.

yeah i gotcah I just dont know when I can get it in to get a leakdown and compression test right now shes my daily driver, all in all it dont seem to be doing to bad, I think since the breather is sitting at a 45 degree angle may be why oil is leaking out of it im sure its getting misted with oil and its just pooling and leaking out not actually blowing out.

I emptied the catchcan and with about 1500[1700 miles on it it had about a teaspoon to tablespoon of oil in it. I also switched the lines from the catchan to how they look in the other posters picture, mine were reversed from that. I think I need a 45 degree neck on that breather and see what happens there, I did notice that there is some blackening on the exhaust tips and it might be suckin some oil threw the intake as well. we will see what these changes doo, I may add another breather just for measure. Josh I still plan to have you take a look at my tune and some other stuff on my car when I can actually afford to have some down time on it, right now I cant and I am going on leave next week also and will be driving it. since the breather though it hasnt pushed oil out anywhere else so maybe this is just something simple and nothing major. but I am still going to do a leakdown and compression test since this engine has never had one while in my posession

Things can be simple and work... KISS- Keep It Simple Stupid. In all different motor sports from 2 stroke to 4 they run breathers... Why? Because it is simple and it works.

:cheers:

@ The op, the breathers I run can be found at any parts store. They're made by spectre, like $10 each.

:cheers:.

:chug:

il do the breathers, but I need to get a 45 degree elbow to get hte one on the valve cover to be strait so if mist does get in the breather it wont leak everywhere.

ok i got a 418 ls3, and when you get on it and get the rpms high this thing builds up so much crankcase pressure it was blowing the oil dipstick out and shooting oil every where, we added a catch can and zip died the dipstick down and everything seemed fine until one time I got on it and saw all kinds of smoke out the back, got the car on a lift and looked like it blew oil out the back of the main seal (i dont think it damaged it) so then we added a breather, things seem to be ok from there but then after about 500 miles of strait driving I noticed that oil was leaking out of the breather.

What is going on with this thing, i figure a catchcan and breather would stop excess crankcase pressure from doing this,

I really need help here i dont want my car shooting oil everywhere when I get on it.

HI-Same Motor with catch can -experiencing exact same issue! My 418 is still at break-in period. :corn:

Thanks

stock logbock ls2,33k miles,carb. car has been running for weeks and i just hooked up a breather/catch combo today. no oil anywhere before it was installed, both valvecover tubes were wide open, no hoses,breathers,or pcv.

both hoses go into an aluminum catch can (one into each side) with a breather on top. done and done.


those diagrams someone posted in a link are the most rube goldberg crap ive ever seen. does it make your coffee too?

im just going to run a breather on each valve covor on the tubes and put the oil cap back on I dont think I am really blowing oil I think its just the fact thers no oil cap and its covering up the breather on oil then leaking out, cause it dont start leaking until its been running a while

So you are still having some sort of problem with the system? You still running the catch can?

Just bought one of these on ebay to go with my oil catch can, hope it works w/o having to do leak down test or buy a vacuum pump $$. Stay tuned.

Thanks 1N_Only for sharing your expertise on PM :)

http://www.ebay.com/itm/290689914020?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_593wt_700

i got a catchcan and breather on each valve covoer now and put the oil cap back on I think it will do the trick but havent put many miles on it

http://www.jdpmotorsports.com/rx-performance-oil-breather-cap-2010-2012-camaro-ss-rx-camss-b

I ordered this because it only vents out and it has a valve that won't let unmetered air in just out. So we'll shall see lol

Ok guys let me help you out. Running breathers or not breathers only does one thing. It allows the engine to breath out the breathers instead of the dipstick,seals,or gaskets etc. There is nothing wrong with having breathers and all engines must have some sort of them. Some systems that breath are called pcv systems. Personally I like a pcv system as I want filtered air going throught the crankcase on cruise and I don't want to smell the venting oil on WOT. The proper way for it to be setup is to make sure that the vents coming to your catch can or oil seperator are baffled which they are on the pass side v/c. The lifter valley line should enter the bottom of the catchcan/seperator. The v/c line ahould enter about half way up the catch can. The pcv line should come out of the top of the can and go to manifold vacum. Now on the drivers side v/c You should have a line that is larger (#10-12) that is either baffled in the v/c or uses an external baffle like an after market breather that has a hose barb not a breather on it. That line should go the the throttle body between the filter and the throttle plate.

At cruise you have manifold vacum that pulls crankcase vapors through the engine crossways using filtered air that comes from the line on the driver v/c. At med throttle the engine is allowed to vent into both the pcv system and out the drivers v/c which then burns it in the engine. At WOTthe pcv valve closes and the system vents all the gases out the driver side v/c to be burnt in the engine. You should not have enough blow by for the short periods of WOT to actually pump a large amount of oil into the engine. If you do you have engine issues. Once you return to cruise the system reverses and cleans all the vapors back through the enigne and pcv system. Once you shut the vehicle off the oil from the catch can drains back into the engine. We have run theis system on good engines at WOT for periods of up to one hour without issues.

Breathers are a band-aid, you need to address the true issues. I have tried and removed breathers on LS1 and LS3 motors. they all leak oil. You need to get a properly set up PCV system and find out why you have excessive pressure in the crankcase, and fix it. It is not normal, and any good builder will tell you that. Also NEVER do any autox/ RR with breathers. the sustained cornering and high RPM fill the upper motor with oil that then FLOWS out the breathers a onto hot parts. Most competent tech will bounce you for having a breather on a LS motor

Breathers are a band-aid, you need to address the true issues. I have tried and removed breathers on LS1 and LS3 motors. they all leak oil. You need to get a properly set up PCV system and find out why you have excessive pressure in the crankcase, and fix it. It is not normal, and any good builder will tell you that. Also NEVER do any autox/ RR with breathers. the sustained cornering and high RPM fill the upper motor with oil that then FLOWS out the breathers a onto hot parts. Most competent tech will bounce you for having a breather on a LS motor

Bringing logic and experience back into this thread is uncalled for.

ok problem is officially solved I put the oil cap back on replacing the breather and then I added a breather to each valve covor on the 3/8 fitting.

just to be clear the breather DID solve the blowback issue with the dipstick and rear main seal, the problem was oil was misting or getting shot up into the breather, pooling in it and then leaking out. i put the oil cap back on and added a breather to both covors so now the oil would have to fight gravity to get out, and no no more issues not a single drop and engine running perfectly fine.

ok problem is officially solved I put the oil cap back on replacing the breather and then I added a breather to each valve covor on the 3/8 fitting.

just to be clear the breather DID solve the blowback issue with the dipstick and rear main seal, the problem was oil was misting or getting shot up into the breather, pooling in it and then leaking out. i put the oil cap back on and added a breather to both covors so now the oil would have to fight gravity to get out, and no no more issues not a single drop and engine running perfectly fine.


:usa: Haters gonna hate. Glad it fixed your problem.

My engine blows oil and the dipstick out sometimes when on the bottle. I have a valley PCV going into a catch can then into the intake behind the t-body. The pass side cover has a small breather and the drivers side is plugged. What do I need to do?

My can is really an air and water seperator. Its like an air comp. type. It catches maybe a tsp or less when I drive it.

i would suggest try adding a breather to the driver side covor if that dont fix it then you may need to look into the piston rings, breathers should solve the problem if its just regular blowback and if your not running a stroked engine and having those kids of isues then it very well may be the rings

i build custom pcv/catch can/breather valve set ups for some guys with the same 'problem' bigh hp/ FI / loose n/a if you wanna pm me.

you guys went in an impressive circle on this thread ill give you credit!

This was my solution, two -10 breathers, i welded an alloy fitting in the rocker cover, i am going to put a -12 in the valley plate with a baffled catch can that recycles back into the sump also.
I am revving this to 7500rpm on the strip, on the rollers i can see it smokes a little after it hits 7k+, so hence i am going with a breather directly from the Crank case.
I dont rev it that hard on short circuit stuff, but only when i quarter it as i need to rev out in 3rd.

Forsome reason the last builder used a vally pan with no vent tube! SO in this case what do i do ?


I have breather on the oil cap
After market valve covers with a tube by oil cap and one in drivers side in the back !
I went and bought two small filters and some tees and a 3/8 nipple to drill a hole in driver side front and add nipple ! I was then gona run two filter between two line and leave system how it is
I have oil issues at high rpms where its pushing out rear seal and motor only have 23 miles on it !


So vent on oil cap then rear driver side hooked into catch can and then out of catch can to intake right before it goes into the intake there is a small pcv valve then goes into intake ! what i was gonna add was another nipple to front drivers side then take the unused nipple on passanger side and connect it to new front drivers side and put two small filter in that line !
God i know makes know since but would it help?

jrp that sounds remotely right but i got lost about 2/3 thru it.
you can do all that but as long as you have an open element on the oil fill, while you wont push your rear seal, you will also not have any real pcv.
are you in va by chance? i see you know steve.