Oil catch can?

[GDI Tech]

Thx jsdirt!!! Love that Elcamino!!

[Jsdirt]

No problem.

 

Yeah, I did too - I sold it like an idiot ...

[GDI Tech]

We all have those we regret selling.....memories!

[RyanbabZ71]

No need to add any fuels to any fires. A few posts have been removed in here and another topic.

 

 

Ryan

[Willshire]

Right in the drop down menu, first listing says "GM Truck 2014+ ...." http://www.eliteengineeringusa.com/elite-engineering-e2-x-catch-can/

 

Dual valve has 3 lines, so the can never loses vacuum, even at wide-open throttle. Single is 2 lines - one to PVC, one to intake.

Does it matter if there is little vacuum at WOT? and on the new trucks is the pcv connected to manifold vacuum or ported vacuum?

 

Edit: I see it now, the factory PCV is connected to the manifold and the second line is connected in front of the throttle body for a ported vacuum source. Does seem like the TB will suck from the path of least resistance and pull most of it's air through the intake filter Just trying to understand why you need dual inlet.

Edited December 18, 2015 by Willshire

[Willshire]

What's wrong with using a air compressor ail/water separator? Isn't that wher the technology was born from?

[Silverado-Hareek]

r Just trying to understand why you need dual inlet.

 

You don't need a dual outlet catch can. The base engine with the stock PVC system functions the same way as if you introduced a single outlet catch can in the PCV line, just without the filtration of the catch can.

Edited December 18, 2015 by Silverado-Hareek

[Willshire]

 

You don't need a dual outlet catch can. The base engine with the stock PVC system functions the same way as if you introduced a single outlet catch can in the PCV line, just without the filtration of the catch can.

I have a good understanding of pvc system, I just wondered why in an application like this you would need a manifold and ported vac catch can unless you were wot all of the time. I do agree that a dual makes no sense unless you wanted to pick up the other 1% of the oil and vapour lost during wot. My 64 came with a factory vac gauge and the only time there is no vac in the manifold is at wot. Even at 90% there is 5inches.

[Jsdirt]

Low or no vacuum will exist under a heavy load at WOT or even a bit below that.

 

As to your question about ported or manifold, I don;t think that applies anymore - that was a carburetor design, so that ported vacuum w ould be sent to the vacuum advance diaphragm, advancing the timing under low load part throttle conditions. Computers handle all that now, and there would be no benefit to the PCV being hooked up that way.

 

I tow alot (and have a heavy foot) , so my time at a low or no vac state is quite often. If there's no vacuum, there's no oil to be caught in the catch can ... but then again it won't be going to the intake either, so now I am questioning the need for this as well ...

Edited December 18, 2015 by Jsdirt

[GDI Tech]

jsdirt is correct.

 

Todays camshaft grinds all have a certain amount of overlap when the intake and exhaust valves are both open momenarily, and this allows reversion pulses to cancel out intake manifold vacuum when accelerating or at WOT especially. These pulses do not reach past the TB until well over 8k RPM's and we don't run these engines anywhere near that high, so to add the secondary outlet has several advantages. First is there is no "stagnant" period when pressure can build in the crankcase and allow those damaging compounds to fall from suspension and mix into the engine oil. The other advantage is it helps maintain piston ring stability for less blow-by and longer life (less wear). Doing the dual outlet allows the checkvalves to automatically switch between suction sources to always utilize the strongest evacuation suction source wether the IM during idel, cruise, and deceleration or the post added upstream of the TB (BMW is the only OEM that is doing this now and they just started). So doing this provides evacuation at all operating levels. And as the Elite E2-X is so efficient (95-98%) when compared to most other name brand cans (15-30%) no oil is really entering. As the system's remain closed, and do nothing to defeat any of the OEM functions, it also retains emissions compliance as well as cannot affect the warranty. Since the addition of the secondary suction source improves and enhances the PCV systems functions, this is an improvement over the current OEM PCV systems functions as well.

 

As jsdirt correctly states, anytime a modern engine is under acceleration there is little to no vacuum present due to the explanation I gave above.

 

Some great intelligent contributions here. What many don't realize is for the past 25-30 years the functions and operation of the PCV system have not been taught in automotive technical schools or training, and the dealers and manufacturers no longer teach it either, so there is so much misunderstood out there as I can see here many are still making "assumptions" as to the function, etc.

 

Also, my viewpoint is from a side many never see or even get a glimpse of as I work in the Automotive Engineering side of this, not the service or dealer side so much of what I share you need to really search to find accurate information on.

 

I am not selling anything here (but definitely endorse the Elite Engineering, a supporting vendor here, systems as we test most of the aftermarket products sold to combat these issues, and GDI engines and the inherent issues that come with them is my works focus the past several years, and we study all makes/models including non automotive GDI engines. I am just sharing accurate, documentable information and data with others. Over 4 decades of working in the industry is what I share. I am not here to fight or insult.

 

So I welcome discussions on any of these subjects, especially GDI related. And no reason for any of us to be rude or insult each other. That sidetracks good threads like this one and others. I don't pretend to be a computer expert, or a financial guru. I don't have a clue how to do what most members do for a living and will never pretend to, but this is my specialty, and it is not self taught like so many performance shops techs are. The automotive industry is a huge slow beauacratic mess to get anything done common sense wise or quickly, so any changes made to an engine/drivetrain/or other major system in a vehicles is like "pulling teeth", and once any is in production, the cost and logistics to make a change, even a minor one is huge.

 

GDI was forced onto most automakers to meet CAFE and emissions standards that are ever increasing, so all the issues have not been worked out yet, but the advantages are many (when in the past would we have thought to run 87 octane in a 11.5:1 CR engine? So we have more power, cleaner (when new) burning, out of smaller sized engines now than ever before (look at the 5.3 GDI VS an old 454 big block of a few decades ago) but with new technologies, come new issues, and these engines are fully capable of going several hundred thousand miles when properly broken in and cared for, but much of it is different than any of us has had to deal with in the past.

 

This morning we tore into a 2015 Traverse with 3.6L V6 LFX engine to inspect and document the amount of coking on the intake valves, and at just over 8k miles, this is just not good to see as far as build-up:

[Willshire]

Understood. I didn't explain very well the manny vs ported thing. Since the TB is a throttle plate, as in a carb, "ported" vac would come from the front of the TB (air filter side) and manifold vac would come from the rear or manifold side. So i guess this is why the dual is essentially hooked up to either side of the TB. I will put a catch can on at some point soon but when you lay down as much money as you did on your first house, money gets scarce. And 500 CDN for an EE catch can is way out of my league. Mishimoto or ADD appear to have something closer to the available funds lol. Heck, i guess if you had to, a diy unit with the wifes stainless pot scrubbers would work right?

[GDI Tech]

Understood. I didn't explain very well the manny vs ported thing. Since the TB is a throttle plate, as in a carb, "ported" vac would come from the front of the TB (air filter side) and manifold vac would come from the rear or manifold side. So i guess this is why the dual is essentially hooked up to either side of the TB. I will put a catch can on at some point soon but when you lay down as much money as you did on your first house, money gets scarce. And 500 CDN for an EE catch can is way out of my league. Mishimoto or ADD appear to have something closer to the available funds lol. Heck, i guess if you had to, a diy unit with the wifes stainless pot scrubbers would work right?

 

Correct. It is also important to place the second barb/port just upstream or in front of the TB as the closer to the main air filter you get, the more dispersion so measurable suction drops fast even though there is a large amount of air moving through, the greatest suction is just in front of the TB.

 

I would look at the lower cost Elite cans, or a Saiku Micchi,(not a supporting vendor) but with a GDI engine, they will not tolerate even a small amount of ingestion where the old port injection engines where the injector constantly sprayed the valves clean and kept them cool could. That is why the dual outlet versions are important with GDI, and using a less effective can is not a good idea. You can spend over $500-$600 USD (more Canadian) on many nice looking cans and still not have more than 15-30% effectiveness. You have a good investment into that truck, think of this as a small price to pay for the protection and piece of mind. And, the truly effective systems also will give 1-3 MPG improvement on average to fuel economy, so depending on the miles driven per year, they do pay for themselves and then some by eliminating most knock retard caused by the oil ingestion. When your engine is not running at optimum advance timing, it produces less power, and runs less efficiently than with optimum advance. The reason the PCM pulls timing when it detects detonation (knock sensors) is to protect the engine from damage. In it's purest form, GDI cannot experience detonation as there is no fuel present in the cylinder until that final few milliseconds before spark is present to ignite the mixture. That is why you can run 11:1 compression ratio on a truck engine on only 87 octane. BUT, any oil most present during the compression stroke will ignite form pressure/heat/glowing carbon, etc. and pre-ignite, or detonate. Left to detonate, a piston soon softens around the top edges and begins to melt, rods hammer the bearings and cause them to mushroom and fail, etc. With the old port injection LS based engine of pre 2014 they were 9.5:1 or so and less power for the same CI, and could not run more than that compression ratio without serious detonation. Detonation is most common under a load.

 

Here is what a 6.2L GDI piston looks like when it experiences detonation:

 

The topography of a GDI piston is far different from a port injection dished or flat top piston due to the completely different technology involved.

 

 

[Willshire]

the catch can tube to the intake also provides a nice easy access to suck seafoam in too! should you choose to do that. The ADD W1 seems to be popular as well or a baffelled Mishimoto

Edited December 18, 2015 by Willshire

[moosehead1]

Truck has just over 1K miles, 400 miles with catch can produced just over an ounce of snot.

 

 

[2015AT6.2]

Got my catch can ordered today. Ordered some black AN fittings to go along with it.