"..and from there a tube runs up from this baffle into the lower housing of the super charger beneath the by-pass butterfly as you can see in jcthornes pictures."

"(as we capped the tube under the SC)"


Is there a picture of this hole or tube that needs to be plugged/capped?
Where is it located?

 

Some info here:
https://www.corvetteforum.com/forums...post1590293763

 

Co speed is cool and got my stuff to me quickly and knows his stuff!

 

Excellent. I would look at either the new about to be released Elite E2-X and the Coloradospeed system. Both equally as effective and the only true solutions I have seen to date. (Oh, so all know I am NOT in sales with Coloradospeed, just tech support. I was hired for this subject).


The sooner you stop the ingestion the better. If over say 10k miles, then the intake valves are already on their way to being deposit laden, and using a solvent based upper induction cleaning can clean some, but be wary if the deposits are large enough using these seafoams, BG, CRC, etc. can cause scouring of the cylinders and pistons as these deposits bake on hard and are very abrasive unlike the old thin soft carbon on Port injection engines, and there are always some particles that are forced between the cylinder and piston during the process. If 15-20k miles on ANY GDI engine, I don,t ever recommend using them as the risk outweighs the reward. Then a manual crushed walnut shell blasting is needed.

Yes:



Detailed instructions are emailed with any that choose these.


Now, let me go onto other popular cans (and please, some that run these will be offended, this is NOT an attack on any, just stating fact as to why and how they do and do not work well):

Most cans if cut apart and inspected are nothing but empty "catchcans" originally designed to capture over flow liquids to prevent them from spilling onto a track, etc. so these work no better than any empty container you could add a few fittings to and install. Due to the fact that condensation will take place, these all will catch some of the oil mist, but on average only 5-10% allow the majority to pass through, so no help period other than a "placebo" feel good effect.

These have tons of brand names on them, several well known, but inside they are all empty. Avoid these if your goal is to stop the ingestion.

Next come the very nice looking, extremely well machined higher priced, usually with "billet" in the name. Only 2 machine shops make the majority of these, and in some of my other threads/posts I have posted the long term test results over months and thousands of miles to show they range from 20-40% effective depending on the size. The larger, the more effective just due to the speed of the flow through them. The smaller a can is the more difficult to prevent any liquid from being pulled up and out from the Venturi effect. The flow must slow enough for not only liquid droplets that are condensed to fall from suspension, but to also prevent liquid already present from being pulled out. You can look inside most of these varying sizes and see the outlet barb may be as close as 1" from where the droplets are falling, so all but the largest drops will be pulled out with the outgoing flow. Other will have (and these are the most common with dozens of brand names etched in, all similar or identical as they are made at one of the two shops mentioned) the coalescing media right tight on the outlet opening as shown here. Now to test this at home, simply take a wet wash cloth and put it to your mouth (clean water!) and suck. What happens? Now the flow of the average PCV system is far greater so what happens to the oil saturated in the media? You guessed it, pulled right through and out of the can. Here are pictures so you can see how this occurs:









Note how there is no designated inlet and outlet, so what is trapped in the media on the side used as the outlet will always allow most to be pulled right out. Take that with the small internal chamber, and the flow cannot slow to the point of not pulling oil through. Anyone with one of these that has any doubt, just buy a cheap glass inline fuel filter from any auto parts store and install between the outlet and vacuum source on your IM You will see in very few miles the oil getting past. These also have only one evacuation suction source, so when ever you are accelerating no evacuation takes place, and pressure is allowed to build, eventually backing up out the cleanside and ingesting oil through the intake tube, or CAI. To properly maintain constant evacuation and avoid pressure ever building you need 2 sources of evacuation suction, the intake manifold for idle, cruise and deceleration, and an alternate for when the reversion pulses caused by cam lobe overlap cancels out the IM vacuum. Only dual outlet cans provide this.

Then we will touch on the systems, very high priced, that should NEVER be used on a street driven car, and I will list the reasons. (And I always get push back on this, but I will provide all the data needed for anyone to verify). These are the vented, or breathered systems.

These all have a few things in common, most defeat all evacuation and removal of the damaging compounds the PCV system removes and is critical for engine life, and they vent pressure through a breather(s) mainly designed to allow pressure to first build, and then vent VS evacuated (pulling vacuum/suction on the crankcase at all times), and this allows almost all the damaging compounds you must remove as soon as they enter as blow-by to settle and mix with the oil and coat the internal parts of the engine. Once these settle and mix, only a portion of the water and un-burnt fuel will "flash off" again to become suspended, but as these systems do not evacuate they settle back again and add to the contamination. The abrasive soot and carbon particles and the sulfuric acid are the most damaging if left in the crankcase. Only the larger particles can be trapped by the oil filter (thus the darkness oil turns) so engine life is greatly shortened unless you change that oil after every run session. Then the issue of crankcase pressure. If left to just build and vent, this will cause instability to the piston rings and cause ring "flutter" which prevents proper seal, and over time will wear small "divots" into the cylinder wall further compromising seal. Vacuum is essential to properly draw rings to seal correctly, so this is an issue that for track use, a belt driven vacuum pump is the only proper solution. With open headers you can utilize collector evac diaphragms to pull vacuum, but any back pressure from mufflers will cause them to fail.

A proper system will always pull vacuum on the crankcase, even if slight to avoid these issues. Then even a vented can that does allow evacuation will disrupt the accurate data the MAF sensor sends the PCM causing short term fuel trims to hint to correct the information received by the MAF, MAP, and upstream O2 sensors. All air that eventually reaches the intake air charge must be metered (measured) by the MAF, so when it is vented, this provides inaccurate data to the PCM so it cannot adjust for proper A/F ratio at idle and cruise. Only at WOT when it defaults to speed density is this not a factor.

And finally, the "Open Hoses" to the ground. This is the most alarming as this brings us back to the old road draft systems, except these I see with 2 hoses, so one will most likely become a vacuum at speed as the Venturi effect will never be equal between both, and one will create more suction that the other from the air passing the openings causing the other to act a s a vacuum cleaner sucking up dirt/dust/water/ etc. directly into the tank, and further into the crankcase.

You can identify those systems as they will take the clean and dirty sides of the PCV system and run those lines into one tank, defeating all evacuation and flushing. They do stop the oil ingestion, but at the sacrifice of the engine. And if anyone running one doubts any of this, at your next oil change, simply collect some of that drain oil and send it off to Blackstone or better yet, one of the other labs that goes even further in analyzing the content and you will see the higher than average contaminates and wear caused by this. Why are there so many different approaches to solve a few issues? The functions of the PCV system are no longer taught in today's tech training. The emphasis is on reading a diagnostic code and swapping that failed part in as little time as possible as the flat rate schedules leave little time for manual diagnostics, and many here have experienced the "no trouble found" or "could not duplicate problem". Not tech wants to work fr free, and very few systems are taught in depth the past 20-30 years and few "old timers" are left any more, and most performance shops are run by talented power builders that have never learned all of these detailed system functions, but are great at quality power builds, etc. In fact, unless you come from the professional race industry you will only think of the PCV system as a pollution control device, and will only look at venting crankcase pressure instead of robust ways to pull vacuum and evacuate. I will go further and make the statement that most have never been taught what the compounds entering the crankcase as blow-by are, and how they cause damage as through the years I have talked to, visited shop after shop and only on a few occasions has any of the techs been able to explain or name them much less think of the PCV system as anything but a pollution control device.

I can post many more pictures of different cans and their make up, but most should be able to follow this and determine what they have, or what they need, and realize almost NO cans on the market came from an actual automotive engineering stand point but were just marketed to meet a growing demand from those becoming aware of the issues related to oil and other compounds ingested via the intake air charge.

And for those that doubt any of the DI issues are still a big concern, simply google "direct injection intake valve coking" or similar, and click on images to see contributions by techs from every auto maker in the world dealing with these and see although great efforts have been made to combat it, in practice very little has helped no matter what the PR people claim. I invite ANY PR spokesperson to meet at a neutral location and select any GDI vehicle they claim does not suffer greatly from these issues and remove the intake manifold and inspect the intake valves with others present to document all, and further I will perform an intake valve cleaning and show before and after dyno runs to show the extent of power loss due to this not mentioning valve guides wore out of tolerance by as little as 20-30k miles and more.

Only 2 brands I can absolutely endorse for the LT4, Elite Engineering and the Colorado Speed systems (or the original RX systems, but they are no longer available and do NOT be confused with the cheap Chinese knock-off's being marketed under the RX brand and logo).

Ask any questions and I will do my best to answer. This is a subject that has so much mis-information floating around you must become educated on and learn the details to make an informed decision, and you have all invested a great deal in what is the most amazing US production car to date IMHO.



Jason.

 

^^^
Thanks for the pic....looks like a tube sticking up. Why not a cap over the tube sealed with some high temp epoxy?
Looks like the only way to get to it is with some long nosed pliers?

 

That would work, but if not perfectly cleaned of all oil residue, an epoxy will eventually be in danger of coming loose, and we don't want anything that could damage the SC rotors if it did. That tube can be filled with RTV or permatex Right Stuff, and as it comes up from this baffle located underneath the valley cover:



so it could be later removed if desired.

Here is the Delrin high temp plug:


Put some sealant underneath, around the plug, and after seating it properly you spread more over the top to ensure no leaks. If any would come loose, it would not cause any damage and would get trapped on top of the intercooler bricks.

For those that have not been following the details between port injection of the previous generations of the LS engines VS the GDI versions, valve coking was not an issue as the detergent fuels would constantly spray the backsides of the intake valves keeping them cool and deposit free, even after several hundred thousand miles:



Where the direct injection does not introduce fuel behind the valves but does so directly into the combustion chamber during the very final part of the compression stroke, so it never touches the valves (new attempts at variable fuel timing events to get some to touch the valves have not been effective in stopping this) so not cleaning OR cooling takes place:


Audi just patented a new design that places the injector between the valves in an attempt to also have some fuel contact, but that undoes the reason why these can run at 11.5:1 CR (10:1 for the LT4) as any fuel present prior to the main injector event can and will cause detonation at these high CR's. The reason GDI engines can run such high CR (which gives more power, cleaner burn, better MPG) is there is little chance of pre-ignition (detonation) as the fuel is only present for milliseconds and combustion almost instantaneous.

Audi can bump up to 19:1 CR with this new design!!! Crazy! But, will have to see what happens with the intake valve coking issue.

Now, let's get some discussions on the different type of approaches and systems others are using. Anything technical on all of this that would help clarify cause, effect, solutions, and pluses and minuses of each.

And any running the latest RX prototypes please share your results on how this has stopped the ingestion.

 

Starting E2 catch can install. I lost about 8 ounces of oil after 7k. I know where some of it is. Looks ugly!

 

What is next after plugging the hole?

 

 

Jason, thanks for this very educational thread, and all of the other good info you have posted in otehr threads. To add more clarification about direct injection engines, do you have experience with boat motors, because they don't seem to have this issue. I'm guessing their PCV system is completely different, and they also run under load most of the time, with very little deceleration.

Not to derail this to be about marine engines, but they seem to have most their DI related issues worked out, and they tend to be more severe duty usage of engines in general. The only reason I'm adding it to this thread is I've been watching DI engine technology for several years (both auto and marine applications), and it will help in the overall understanding of long term issues to be resolved.

And, I want a C7 Z06, this issue is the main one keeping me from getting one today.

 

Another to co speed for the information presented here. All due respect to the OP, but you can't evaluate the options without knowing how it all works, and this is a super-complex issue.

The catch can is the simplest part of it - it just a receptacle / separator. It's what happens before oil gets to the catch can that matters.

Seeing the pics of pooled oil in the S/C intake area, I have to wonder if this is at least partly to blame for cars losing power. There is a tremendous amount of blow-by on these LS engines due to the low-friction piston ring design, and all that oil pulls the octane number down significantly, in addition to causing long term issues.

I had a H&C (NA) C6 and blow-by and oil was my biggest issue with that motor. Boost makes all this worse.

Now excuse me while I go back to page one and start reading up...

 

None taken. But i would have to say that I do know how they work in the general term of things as explained, but I do not have experiences with this platform or the previous corvette platforms to judge which ones are designed to work better than the others.

And with very little information on the different products available, I was hoping to clarify that. As mentioned, even vendors on their website have very little information regarding their systems, how they are different than anyone elses etc or how they fit / look.

The reason, as mentioned before, that I didnt want this to really be a discussion of sorts is that ive seen other threads degenerate when people are asking questions and then responding with opinions that differ.

 

I cleaned my blower cover and the top of the blower real well.
Plugged my hole and and have a new spot for the catch can.

This is an E2 but it fits nice with a 1 1/2 steel spacer under it.
I think it can even be emptied with out unbolting.

Need Help on the rest of the routing of the PVC help!

 

Agree, and understand. Perhaps one thing we can do, is agree that co speed is the resident expert thus far, and the rest of us (consumers) are here to learn and should focus on reading what he has posted and understanding it all. Then we can go on to the products themselves.

We are fortunate to have co-speed taking the time to educate. Most vendors seem to just throw the product out there with no explanation of why it does what it does.

 

Thanks all! This is what makes taking all this time (and I get paid) worth it. Good work 3 z06ZR1 so far, will email you shortly.

Daisuke has also been great starting this thread for everyone's benefit and he is learning a ton as well.

Seadawg,

The GDI 2 strokes we are NOT seeing much issue, and this I attribute this to the clean burning 2 stroke oils, but the 4 strokes we are seeing this, just not as serious and again, they are run at high RPM's and loads most of the time so the velocity of the incoming intake air charge being greater may help. But, all are under EPA requirements to have closed PCV systems. Snowmobiles w/4 stroke GDI as well have this, and motorcycles are seeing in more rapidly (again, snowmobiles are generally run WOT or nothing, at least we always used to!).

another thing is, I am not aware of any of the major brands of outboards that are NOT broken in in the test tank at the factory and they come with rings already properly seated so little excess blow-by unlike cars/light trucks where most still follow the (incorrect) break in instructions in the owners manual that makes proper ring seating a chance at best. Also, I am not aware of any motorcycles (big brands) that are not also broken in at the factory on the engine/trans dyno. Take the Honda's, they run to redline and back several times through all gears before the rest of the assy is completed. Outboards are just before the final covers are mounted, and under load in the tanks. Only the Mass produced cars are not (and not, GM nor Mopar break in the engines on a dyno before installing like some mistakenly believe, they are run to check for leaks and noise, but that's it.

ALL supercars, including the Nissan GTR are broken in on engine dyno, chassis dyno, and closed track runs though.

Excellent discussions going on here all! Please keep them coming and spread the word to get more in this thread.

 

The emails were helpful now I'm ready to finish.
This I hope with keep the exhaust tips clean that's the test.
if they get cover with soot and crap you know stuff is getting in there.
Straight fuel burns clean as should your tips!
I like my can location.
thanks again!

 

Best complete info on this subject for the LT4, thanks!

I must say its a bit bothersome plugging a hole in the engine that GM drilled! I would guess if that plug came loose and did get into the rotors it would get chewed up and spit out without hurting anything, right??

I'll be on the can soon!

 

Correct. The reason it is now Delrin instead of aluminum.

Also, very important to properly seal the pug underneath, around, and on the top.

 

The catch can effectiveness will have next to no effect on the cleanliness of your tail pipes.

Most of the black soot on the bottom of the outer two pipes is a result of condensation in the exhaust tubing. Engine exhaust contains water vapor and when the car starts, the exhaust tubing is much cooler than that exhaust. The water vapor condenses and water runs the length and drips out the tail pipe. There is some amount of carbon soot in any exhaust system. Run the water through the carbon soot and it gets dirty. That leaves deposits on your tail pipes.

 

Correct. But it should no longer be an "oily film" just the soot you describe which is easy to clean. First start up in the morning have someone else start your car while you watch tailpipes and see just how much water accumulates after sitting overnight, and this brings that normal soot out onto the pipe ends.