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Old 06-11-2013, 08:48 PM   #21
SC2150
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Drives: 2012 Camaro RS, RX supercharged
Join Date: Dec 2009
Location: Bradenton, FL
Posts: 6,063
We have a LLT with 64k miles on it with a RX catchcan on since nearly day one....absolutely NO intake valve coking.....and we see the results daily.

Yours is about the cleanest I have seen at that mileage except the one, that is how most look.

Here is a link to pictures submitted by techs from every DI engine in the world pretty much (including motorcycles) and with over 12,000 of the RX cans in use there are hundreds of members here that can show the results.

http://www.google.com/search?q=intak...w=2021&bih=875

Take the time to look at these pictures.

99% plus of the valve coking is a direct result of the oil ingestion via the PCV dirty side, and if you use a oil separating catchcan that actually catches and traps all, or nearly all the oil, then you have zero issues (again, hundreds of members here can remove there intake manifolds and show this).

Now, install the average can and 99% of them let 1/2 or more of the oil still pass through (no matter the name brand) so you have only 3-4 on the market that actually do trap all, or nearly all the oil.

If you click on this thread, part way down the page are most of the cans people buy today with cut aways or disassembled to show what is (or is not )inside of them plus a explanation of the testing results of what percentage pulls through most cans and why they do, or don't work well.
http://www.camaro5.com/forums/showth...=265217&page=3

Pretty much the RX, Elite, and Saiku Micchi are the ones that trap all or nearly all (no, Elite does not pay me a commission, I report the actual testing and the results).

In the days of port injection, running a top tier fuel would keep the intake valves (and the area of the port the spray makes contact wife) clean. Look at a shell commercial to see the pictures of a old port injection engine valve run on a cheap fuel VS their techron.

Now with direct injection, no fuel touches the intake valves...only the air charge passes it so there is no difference in running a top tier vs a cheap (all come from the same bulk freighters here at the port of Manatee near us and the end user (shell, mobil, etc.) add the additives before delivery to the station).

So, as long as you have 1-2 qts of oil ingesting through the dirty side of the PCV system, you will always have the severe valve coking we see on ALL DI engines. Audi's V8 does have a secondary port injector to help eliminate the low RPM hesitation inherent with DI, but it only slightly reduces the coking.

You can also see the results of running a RX catchcan vs no can, or even one of the cheap ebay ones (or an expensive billet can with a poor design allowing oil pull through):

Anyone with a LS3/L99, remove your TB and look inside your IM and see what is ingesting. This car came the next day after delivery from the dealer:


Picture of SC and housing using a RX catchcan from day one for 16,000 miles VS a intercooler after 14,000 miles w/no can:









Scouring on pistons from carbon breaking loose:


Oil ingestion causes buildup on the piston rings and ring lands preventing them from moving freely to properly seal...resulting in loss of power and excess oil consumption:



Actual pictures from GM TSB:




Intake from LLT on left w/can from new, right w/out:



On any FI engine, the detonation caused by the oil ingestion results in a good deal less power than the same one with the oil ingestion stopped.

And, for those that delete the PCV systems function, then engine damage and premature wear is the result.

As part of the combustion process there is a good deal of pressure, or "blow by" that gets past the piston rings into the crankcase, and this is made up of several damaging compounds that if not evacuated while still in a gaseous, or suspended state, will condense and settle into the engine oil and on the internal parts when the engine cools down after shut down.

These consist of water, unburnt fuel, abrasive carbon particles (many to small for the oil filter micron size to remove and trap so they continue to circulate with the engine oil wearing your engine prematurely), sulfuric acid (which etches the crank & cam journals and bearing surfaces once they reach a certain PPM) and other damaging hydrocarbons, etc.

A PEM PCV system uses the intake manifold vacuum to evacuate these damaging compounds while the clean side provides filtered metered fresh air to make up for what is evacuated.

Ideally you want filtered fresh air entering one bank of the engine (on the V6 it is the rear of the drivers side valve cover) where it passes the valve train, is pulled down into the crankcase, all the while flushing the damaging compounds out with it while they are still suspended any time the engine is running. They then travel up the passenger side bank, past the valvetrain and out the rear of the passenger side valve cover where the intake manifold vacuum pulls the compounds into the combustion chamber to be burnt and further burnt clean in the catalytic converter. The issue is the oil most pulled in with this.

Now, if you delete this function, or break this flow (by just adding breathers to release pressure or take the clean side and dirty side and run both lines into a single can, you then are only relieving the pressure. Every time the engine is shut down and cools, all these damaging compounds condense and fall into the oil where they cannot be removed without changing your oil and the concentration accumulates and increases with every start up and shutdown. That can shorten engine life by 1/2 to 1/3rd what it would live with proper evacuation.

Also, every street legal gasoline car and light truck sold in the US today has a functioning PCV system that evacuates and flushes the crankcase for long engine life.

ANY deletion or disabling of this function will result in premature wear and is also grounds for any manufacturer to void a warranty when such an important system is disabled.

A proper catchcan system simply installs inline on the dirty side to trap this oil mist causing all the issues and does not effect the evacuation process......but far to often we see those that do not understand this aspect of the PCV system and only think of the obvious...the crankcase pressure.

So, you do NOT want oil in the intake air charge. You do NOT want to delete or disable the PCV systems evacuation process with a separate clean side source and a dirty side. You NEVER want to mix the clean and dirty sides (this defeats the PCV systems function, and you can stop all, or nearly all intake valve coking with one of the few truly functional cathcans on the market.

And there is so much misinformation and misunderstanding of the PCV systems functions, that you do well to study all I have posted here.

:thumnbsup:


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