catch cans threads strewn about
http://www.nsxprime.com/forum/showth...=1#post1862819
https://www.evolutionm.net/forums/ev...l#post11872416

oil control and pcv discussions
http://www.nsxprime.com/forum/showth...=1#post1909408
https://ls1tech.com/forums/generatio...-race-car.html

recent crankcase pressure post
https://ls1tech.com/forums/road-raci...l#post20132955

 

Before I picked the car up in May, there were a few misfire conditions due to pushrod length, detected using an infrared gun on the primaries. After testing injectors, moving injectors, swapping plugs, swapping wires, etc, we ended up putting in slightly shorter pushrods on those cylinders, and the gun indicated the problem was resolved. Once the mechanical misfire condition was corrected, I simply put the desensitized misfire tables back to the way they were with the prior motor. After putting the factory misfire tables back to stock as a test a few days ago, I did get a flashing SES once but it didn't feel like it was missing. I didn't have my laptop with me to log at the time. Yesterday I performed the first CASE relearn on the engine even though I didn't ever receive a P335, P340 or P1336. I would have done a relearn sooner but HPT's published directions were incorrect and I also read you didn't need to do it unless you set those DTCs. I fixed my HPTuners misfire charts to work with v4.4, so I'm ready to desensitize the tables again; the method I use to desensitize the tables moves the values just enough to not trip it... it's not blindly setting the cells to 32767. Should I get an infrared gun that supports a certain temp range and recheck the primaries?

The current motor was just built in April 2019; I re-used the same block, parts are new unless indicated otherwise.

Later gen F-body pan that uses the M22x1.50 oil filter thread
Improved Racing crank scraper
Improved Racing oil pan baffle (re-used the old part)
Mahle 930223280 pistons setup with .0031 piston-to-wall clearance (Mahle recommendation is .0025-.0033 P2W for this piston)
Mahle 4085MS-112 ring pack, top gap is .018, second gap is .022, oil gap is .018
Johnson ST2126LSR lifters (axle oiling)
SACCity Billet oil galley barbell
Manton 502 pushrods with .040" restrictors

I provided the shop the SACCity Oil bypass delete part but they preferred not to use it. I technically have 3 pushrods installed on the passenger side that are unrestricted due to a mixup on an additional order with Manton, but I have the correct pushrods waiting to go in.

Whereabouts do you live in FL? I appreciate the chemistry and physics, it helps me understand. The end goal is to isolate this potential problem and if it is truly a problem to worry about, determine what fixes are available to me.

You comment:
"Engine D is losing enough oil to actually get my attention and show up on the plugs."
"Engine E is now obviously having an issue with compression seal. One or more of the compression seals is leaking into the crankcase and pressure is helping the oil pass the baffle in significant amounts."

Yet I am not seeing any oil contamination on a sample spark plug (#2).What can cause high oil in the catch can if it's not showing up on the plugs? Should I still perform both a compression and a leakdown test?

In one of your posts, you mentioned using this crankcase pressure sender. How do I know which size I need? Where would I plumb this in?
https://www.ebay.com/itm/MultipleTyp...PjKGZAIIfkZy0Q

 

thanks for questions
Oil can show up on just 1 cylinder sometimes so be aware when checking 1 that a different one could have oil. it isnt always all of them that gets it.
Theres lots of ways oil can get into a cylinder, like the rocker threads Im sure you know about on some engines. People will 'seal' the threads using thread sealer, which is fine, but just like a rear main or valve cover gasket the thread sealer is a 'pushable seal' that crankcase pressure can work on over time, wearing it down, eventually creating a leak in 1 cylinder for example.

I always recommend compression/leakdown tests, no matter what. Even if the engine is healthy, I still perform those tests frequently (whenever the opportunity arises) because just like performing an oil analysis (blackstone) each month (some of my friends do, I cant afford it though) it gives you an idea of how the inside of each combustion chamber is 'changing' over time. For example 6 months ago it was 150psi, 3 month later 140psi, now its 130psi, something is wrong even though it runs fine. And if you didnt do the first and second test you would have no idea what was happening.
Same idea with leakdown.
With both those tests, sometimes the exact numbers are not as important as their equality, or differences between them. Like an engine that has 170psi on one cylinder and 150psi on another cylinder, but the FSM says 145 is the lower limit... you might be tempted to go "ok its within FSM limit" but the reality is the engine might NOT run smooth if the compression isn't nearly identical in every cylinder. And I don't necessarily mean physically to the driver; at high RPM the feeling might 'smooth out' but in reality its like having one short leg and one long leg, theres going to be vibrations that potentially create wear which may be imperceptible to human feel/hearing.
Knock is the same way (it starts outside of human hearing which is where knock sensors detect it) but thats another story.

Catch cans... I never use unless the engine is hurt. If I see one on a mostly stock engine I assume the engine is hurt or the owner has no idea how crankcase systems work.
When is it advantageous to use a catch can? If you built an engine but blows oil for some reason, even with a properly setup crankcase system, and you don't want to rebuild the engine again so you just let it blow oil.
Oil blows out motors two basic ways:
1. crankcase pressure
2. crankcase oil seal failures/cracks, improperly designed oil baffle for the application, improperly mated oil control surfaces, physical deformations in materials, etc...

To this end I suggest getting a handle on the crankcase pressure FIRST (because its a very simple and overlooked system to implement) and THEN if you still have oil control issues to look at the baffle and oil seals directly modifying them as necessary.
If the engine has a turbo I recommend putting that sensor right on the line that feeds the compressor from the crankcase. If you don't have a turbo then put it on the line that feeds the crankcase from the engine's air filter. In both cases that line needs to stay free from oil at all costs so it's a good place to assume there wont be any oil to interfere with the sensor. If you see any oil in that hose it means that there is a serious problem, so I keep that hose handy and check it often for oil, its like the engine's life line. I assume you have no such hose yet so this is a fair warning to set one up if you want oil control at WOT and don't have a dry sump/vacuum pump.

Lets look at a paint diagram I drew rapidly for mostly stock engines
we always start with the stock stuff because it teaches us how the factory intended these systems to work in the first place. If you jump right into some high performance **** it gets confusing what is the purposes of all those hoses and cans?

This stock type of setup is ideal for good pcv suction during light load, cruise, idle, high vacuum.
Note that the intake manifold suction orifice is as SMALL as possible, and that we are going 'slightly large' on the fresh air vent tube.
Setup like this, a factory vehicle will often achieve in the range of 88-94KPA in the post air filter tract (using a dirty, stock paper filter) at WOT.
The factory intended this on purposes because that low pressure area then pulls on the crankcase at WOT, which is generally over 101KPA at WOT.
So you see air flows from area of high pressure to low pressure, we have created a PCV FLOW DIRECTION towards the engine's intake manifold at WOT using this method.
This allows the intake manifold to scavenge crankcase blow-by gasses and puts a slightly negative pressure in the crankcase during WOT which helps control oil seepage, leaking, keeps it from gradually working its way past oil seals (front & rear mains, covers, etc)
It will cost some power of course, which is why this method is not favored among the highest output crowds. So this method is for people who are willing to give up some hp in order to better control over their oil systems.

Okay, the baffle system next,
In the valve cover is an oil control baffle. Every engine uses one but they are all different, even between years. The oil baffle's job is to simply separate oil from air so the pcv can pull mostly air into it's hoses instead of oil.
When do we need to modify the baffle?
The engine's output character or application changes dramatically sometimes the baffle is no longer adequate. Its really hard to tell if the baffle is the problem when you don't have access to crankcase pressure logs- because high crankcase pressure will simulate a poorly designed oil/air separator problem.
There are different ways a baffle can be inadequate. One is oil pooling, liquid oil collecting in the head when the engine's rpm exceeds factory expectations or when the high rpm constantly seen on a track pushes a bunch of oil into the head, and it pools in or near the baffle, and basically submerges it to the point that the oil is pulled out out o the baffle in liquid form. Some engines merely need their baffles drilled (On honda-tech I read this is a solution to some S2000 motors that are used on a track) to facilitate drainage. Others need to be cut open , modified and re-welded closed. Sometimes a tube is added to return oil to the oil pan from the baffle (this is done on several OEM engines btw such as sr20det before 1995 when oil baffle tech was 'low')
Another way a baffle can be overwhelmed is what the shaking/flurry/whipping action of an engine exceeds factory expectations. Imagine shaking up a drink cup full of oil, with the lid not really that tight, the more you shake the more oil spills out. This again requires baffle modifications but drilling holes and adding tubes that connect the baffle back to the oil pan won't help any because the issue isn't just a liquid component that is collecting somewhere, its a physical splashing/splattering of oil that is gradually working through the baffle.

Enter the oil can
If you didn't want to give up the hp used to drive the PCV action at WOT, you might need a catch can. It depends how much blow-by the engine creates and how good the baffle is to begin with, and how much you feel like modifying the baffle, etc...
catch cans are band aids. I would do everything i could before using one, but in the end sometimes it is necessary.
Essentially the steps are:
1. control crankcase pressure
2. update engine oil seals
3. verify crankcase pressure is ideal during the 'oil problem situations'
4. update/modify existing baffles to better separate oil/air
and finally
5. install an external 'baffle' (a can on the outside of the engine which further separates air from oil)
notice the catch can is essentially doing the job of the engine's internal oil baffle. They are practically the same thing when used properly.
The reason you don't want it external is because generally adding volume to the crankcase reduces the effectiveness of the entire PCV system.
for example imagine you added a 5quart catch can to the crankcase and tried the above method for WOT crankcase pcv suction to the intake... It would now have to pull on that entire 5quart can in order to drop the pressure inside the crankcase.
So the best way to use an external can is to use the smallest possible unit volume you can afford, and if possible it should contain a drainback to the engine's oil pan in order to prevent stagnation, oil mixing with water/condensate after shutting off which is typically seen in blind-end catch cans. You should think of the catch can as an extension of the engine's crank case, therefore, the oil quality inside the catch can needs to be as good or better than the oil inside the crank case, at ALL times, because the two are exchanging oil while the engine runs (oil vapor, suspended liquid and also gaseous state lighter hydrocarbon chains of oil are present especially at typical engine oil operating temperatures).

This is turning into a book so I'll let you ask more specific questions I guess
I live in south florida but frequently drive to orange city/orlando and also down to miami

 

The shop did say they performed a compression test after the motor was built, and said the number was above 200psi. I don't know if they checked all the cylinders. I'll have to track down an independent tech I can trust for the leakdown & compression checks, to make sure they dot their I's and cross their T's. Yes, I'm familiar with the rocker arm bolt seals; my tech who moved up north says that none of my rocker arm bolts protruded into the ports during assembly. They're supposed to be unported stock heads, but they are milled.

I don't have a turbo, dry sump or vacuum pump, so "put it on the line that feeds the crankcase from the engine's air filter." Your diagram doesn't quite match my hose routing; mine looks like the diagram immediately below. The passenger valve cover is attached to the throttle body, not in the tube between the MAF and the TB. Is that fine?



Here is the stock PCV system that came on my original LS1 motor (I have an LS3 now):



My concern about the A/O separator draining back into the oil pan is if the can is capturing **** I don't want back in the pan...moisture, etc. How do you prevent that? I live in an Orlando suburb, feel free to contact me if you plan to be in the area.

 

you say "except mine goes from X and Y" but it looks exactly like the picture, So I don't know what you meant,

I am in orlando right now but leaving tomorrow lol

Here is some things to consider:
I see you have one of the valve covers blocked off, I wouldn't do that. Use every available hole when it comes to performance PCV to your advantage.
Make that valve cover baffle work in your favor by using it to help fresh air vent the engine if nothing else. By dividing the flow between them it will reduce the chances of oil aspiration.

I see you are using valley cover for intake manifold suction, but it goes through a can. And you said the can is collecting oil.
There are two kinds of PCV action, lets call them passive and active.
The intake manifold suction is an active suction. Its very powerful since engine vacuum can reach negative 13-14psi (massive vacuum such as during decel).
Notice in my diagram it says 'use the smallest orifice possible that still generates adequate idle/cruise crankcase pressure' and then it gives the typical ranges to shoot for.
This 'active' side of pcv system should NOT pull any oil, ever, never ever, even on a blown up engine, because there is VERY little blow-by while an engine is at idle or cruising. Usually when people have an oil related issue on this side of the pcv system it is because the check valve orifice is TOO LARGE, or, the orifice on the passive side is TOO SMALL (the one in the diagram that says to "oversize" for this exact reason)
Another potential issue is the baffle inside that valley cover might be inadequate. I refused to run the LS6 valley cover after I saw it in person for a variety of reasons; I recommend for the time being, just temporarily to disable it and utilize the valve covers ONLY to see if that dramatically helps with oil issues. I say that because its basically free to test/try so why not.
To way to do this properly is install a factory PCV valve in one of the valve covers, then PRESSURE test the intake to ensure it is working properly (pressure test vid coming).
Then, Run THAT line to the catch can and back to the intake manifold suction. It wont matter if there is another pcv valve in the can ( I assume/hope there from looking at the picture)
The factory PCV valve orifice will limit the flow to an acceptable amount (since you do not currently have a pressure sensor to adjust it manually), therefore eliminating the possibility of that being the issue. The can will catch oil if it still pulls from the valve cover for some reason.
Make sure you clean the can out completely so you can see if any oil is "new" inside it.
If it does pull out of the valve cover, maybe you are using the wrong valve cover port. I notice one of them has two. I am unfamiliar with that engine; on my engine there is only 1 hole on each valve cover and both are identical; So be sure you have a factory pcv valve in the factory location of the factory valve cover. If it will even take one.
Either way, pressure test to ensure the system is working properly. Without the pressure test its 50/50. A high quality check valve is usually an essential item on high performance engines using boost, it wouldn't hurt to use one in general. The factory pcv is just for testing. You can buy a superior quality unit online.

The passive side of the pcv (fresh air tube) is where you get oil when the engine is hurt, or the engine has massive blow-by, or when the line becomes clogged (pressure builds up in the crankcase as a function of time). If you are not seeing oil here, this is a blessing and completely NORMAL for good engines, it means you should have NO problem with preventing oil from getting into the active side as well. Basically, traditionally, catch cans are used on THIS side of the pcv system to band-aid blow-by.
Your issue of intake suction pulling oil is not related to blow-by.

 

I think I wrote something here and here about the oil return options
https://www.evolutionm.net/forums/ev...l#post11871298
https://www.evolutionm.net/forums/ev...l#post11872416

https://forums.nasioc.com/forums/sho...5&postcount=99

 

I just meant mine connected to a small orifice on the side of the TB instead into the tube between the MAF and the TB.

I think I could make time tonight if it was convenient for you.

My can looks like this inside:
http://www.mikenorrismotorsports.com...atch-cans.html

I believe the original LS1 had different valve covers and it definitely had a different PCV system than the LS3. It had a PCV valve inline somewhere on the passenger side of the TB. If I remember correctly, it was discontinued when they implemented the PCV inside the valley cover. I've seen some LS3 PCV diagrams using a U-tube to directly connect the valve cover with the intake manifold.

I'm inferring the passive/fresh side is the clean side, i.e. the tube between my passenger valve cover and my TB? I had the TB blade exposed the same weekend I last dumped the oil out of the can, and the only thing unusual in front of the TB blade were minor brown flecks on the bottom of the TB bore, nothing on the blade itself.

 

I would NOT use a tube near the throttle body. Take the fresh air from just after the air filter. After the maf if you have a maf, I guess.
That tube needs to be near atmospheric pressure to work properly (to feed the crankcase) and when they are near the TB its so close to intake manifold vacuum I would be worried it won't see atmosphere when it needs to. Most OEM intake tubes have a nipple after the air filter, never near the TB.

Thinking about the valley cover, I'm worried it isn't suitable for intake manifold suction.

Thats the thing with the pcv system, a little error here, a little trouble there, and suddenly you have oil going places.
I'd use the valley cover as part of the fresh air vent tube if it doesn't have a check valve (my LS6 valley did NOT which is why I decided not to use it at all)

Test the valley cover for check valve action. If you can 'blow' through it both ways- there is no check valve. that means it isn't really intended/ideal for intake suction. It would complicate things, having a 'second' check valve there.
Mine wasn't.

Also I would not rely on anyone to do a compression test. OR leakdown especially. I mean, if you have to, skip the leakdown, just do a solid compression test.
The rule is, never use a rental. And if you do, use two or three different ones, especially if you get bad results. They are often BAD. If you leave air 'inside them' without releasing it, it will ruin the tester, thats how the rentals die. Also don't rely on a cheap one. Use a high quality tester, and also another one, always get 2x different testers because... most of the time one of them is bad and it will have you rebuilding the engine, laughing.

As to the valve covers. Pay close attention to which 'holes' are for fresh air, and which ones are intended for intake suction. Look in the service manual or whatever.
For performance it helps to have 2 or 3x fresh air vents, but you only need 1 intake suction with a check valve.
Never run more than 1 check valve (keep it simple) and never run more than 1 hose for intake suction on the crank case (simple).

sorry Ive been out all day with family. Sister is going off to college and stuff. Not sure there is anything I can really do anyways, besides look it over up close.
If you are near 17/92 orange city, like around New york avenue and Hamilton, just happen to know this area? PM me and ill send address. I was going to leave afternoon but its no rush.

 

was thinking about a couple minor updates about the sensor,

first the sensor in the auction is poor resolution range for measuring crankcase pressure. I only suggested it because it was cheap and the only one I could find short notice. The more into 'racing' you are the better your equipment needs to be, so I wanted to update with what an 'ideal' sensor would be.
Since we are measuring pressure certainly in the range of -3psi to +3psi for wet sump, you would want a sensor in that range. There are hundreds out there I am sure, they are just hard to 'sift' through if you don't regularly do that sort of thing. In other words there are hundreds of random map sensors for use on pcb that will measure in that range its just a matter of knowing where to buy them, Ebay isn't always the best option. And I don't have any off hand in mind, but during projects at school I've seen the lists of those sensors and there are probably thousands.

Next a word on placement, I said the fresh air vent tube but I thought I should mention that it needs to be near the engine, as close as possible. In fact you could almost just put it in the valve cover. But I wouldn't want it to get much oil on it, so keeping it just a few inches from the cover might be a good idea. Just be sure not to put it too far away because the closer you get to the air filter the higher pressure will be at idle, and lower at WOT, so it will affect the readings in an adverse way.