Now that I have the routing correct, I am curious as to how it will function. It was terrible before so, i'm hoping things will start improving.
Now that I have the routing correct, I am curious as to how it will function. It was terrible before so, i'm hoping things will start improving.
When 1 gallon of gasoline burns it will produce about 1 gallon of water. The crankcase is mostly full of water because blow-by gas contains mostly water and CO2.Originally Posted by gtstorey
By installing extra lines/can to your pcv system you have created a pressure/temperature drop of friction and volume which will condense water from blow-by gas and allow that water to combine with engine oil, which is an opposite of what PCV is intended to do. PCV should bring high velocity high energy gaseous water molecules back to the combustion chamber before they can interact with engine oil, the lines need to be short as possible and high velocity to avoid contaminating oil with water.
When you are collecting water in the presence of oil and heat cycling it, you are facilitating side reactions involving the heating of engine oil and water molecules in the presence of CO2 and other carbon configurations which have myriad possibilities such as carbonic acid the acids that dissolve and rust the exhaust system, you have introduced that into the intake pathways with your little can. The chemistry behind catching oil is insidious and the reason why no auto manufacturer would ever do such a thing. Everytime you shut the engine off the water and carbon interact forming by products, some gas, some liquid, some solid. Then you start the engine and the process cycles, some gets shunted directly into engine vacuum where the products you form overnight while cooling/heating are ingested and those forming hard carbons or deteriorating metal and so forth of the engine. Due to law of partial pressure as the flow or vacuum of the system changes various gradients of gasses form at the surface of liquid over time which cycles local liquid density as a function of pressure and dissolved gasses, like layers of sediment forming various compounds then being mixed by the running engine the next day and re-heated to form new layers of various products and the cycle never ends.
It does indeed turn into water vapor and carbon dioxide and produce roughly that much water, but the majority of that goes into the exhaust. I don't know the exact amount that makes it's way into the engine's crankcase. I imagine no more than 3% and if not able to be drawn out it will heavily condensate. Short tripped engines where the internals don't get hot enough to evaporate the water condensation are usually the ones that rust up.
There are actually engines produced from the factory that have "catch cans". You just don't have any way to drain them as they have built in drains to allow the oil to run back to the pans. They did this for furthering emissions. You'll find these on most newer engines. Hemi's and GM LT's are prime examples. The LT1 actually has a plastic catch can hanging on the front of the engine with a hose going back to the block to catch said oil condensation and drain back into the engine. It's all about emissions. The whole reason the PCV system was introduced in the first place
I've never thought about it from a friction material standpoint and could see why they use the plastics and rubbers that they do. Interesting on that part.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
Lets say the leakdown of each cylinder is 3% then and take 10 gallons of fuel over 200 miles at 3% conversion to blow-by gas of water and CO2 for the crankcase. How much water is that from 200 miles of driving that has entered the crankcase?
You are looking at a tiny percentage of blow-by but discounting the rate of it's accumulation over time. 3% of 1 gallon of fuel burnt is insignificant? But 3% of 50 gallons of fuel over 1000 miles which is what is being exposed to the catching system and heat cycling and side reactions and so forth. It isn't bad or a problem for a crankcase when the PCV system is fully OEM, maintained and functional because there is no aftermarket condensation box attached to the side of the engine.
Every engine has that, its a baffle in the valve cover or wherever. That is the air/oil separator that all engines must have. The separator is designed with a specific range of input gas velocity and mass flow to work properly. By adjusting input or output lines/friction it changes velocity and mass flow which can negatively influence separation which leads to suspended oil in the PCV flow.There are actually engines produced from the factory that have "catch cans". You just don't have any way to drain them as they have built in drains to allow the oil to run back to the pans.
Here is one on a 1989-92 Nissan sr20detThey did this for furthering emissions. You'll find these on most newer engines. Hemi's and GM LT's are prime examples. The LT1 actually has a plastic catch can hanging on the front of the engine with a hose going back to the block to catch said oil condensation and drain back into the engine. It's all about emissions. The whole reason the PCV system was introduced in the first place
Its not new or strictly for emissions. Its for separating oil from the air that must return to the intake air pathways. But when users install catch cans they do not have organic chemistry background to understand the fraction of oil gas or partial pressure of hydrocarbons as a gas state will never be caught in any kind of can or vessel, because it is a gas. Liquid oil can be separated because those are droplets with mass that can achieve separation at specific kinetic energy around a corner but the actual oil vapor is a gas state and cannot be captured or separated- it can only be reduced in oil gas density, and that is done via controlling pressure. E.g. lower pressure contains fewer moles of oil per unit volume of crankcase blow-by gas.
Probably why your better companies put fiber mat materials in the cans for the oil molecules to cling to and drain down from then??? You might want to look into Elite's systems. They claim to pull vacuum even under wot for best ring seal and crankcase scavenging. If this is true, which most independent test show it to be, then this would be better than the OE. Either way the OE has and is using catch can type devices to catch and keep oil in the engine and for it to not wind up in the combustion chambers
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
Less oil in the intake
- cleaner intake system
- less octane reduction
- fewer carbon deposits in the combustion chamber and on the piston
- decreased ash contamination of the catalytic converters
They work, and they work well. Do I really need to go unscrew the bottom of my catchcan and show you a picture? It's filled with about 8 ounces of emulsified mess every 1000 miles or so. The fact that there is stuff in it means that the PCV system is still drawing correctly. Theory vs application.
Or throw a brass brillow pad in the bottom of an el cheapo lol.
Oil is good for the throttle valve and turbochargers. Have you never removed the intake plumbing and taken a paper towel and some WD40 and a pick and wiped the valve and picked out the bits of grit from around the crevice and then sprayed WD40 on it to keep the metal materials from oxidizing? The amount of oil brought to the throttle valve or turbocharger is set by the manufacturer as a form of long term maintenance. All metal materials everywhere in the world desire a lubricative oil coating for protection. Oil in the intake plumbing adheres to the sides where it collects debris that passed the air filter, now you can come along later with a paper towel and wipe it out after 10 years or whatever. That film of oil coating protects the ferrous materials of a compressor wheel and throttle body.... it is desirable. The amount of oil hitting those parts is set so low that it is negligible with respect to oil that passes the piston rings or glides on the cylinder. It is negligible compared to the oil getting around the engine from other pathways. Remember that gasoline is carbon and creates hard carbon coatings on items like intake valves , the same carbon that oil is composed of. When we see carbon up intake valves it wasn't the oil that accumulated there, it was the gasoline when the engine is clean and proper, the spray pattern is evident if directed at the back of the valves. Oil vapors and gasoline vapors both condense over time forming hard carbon deposits. There is a carbon cycling in the combustion chamber where partially reacted hydrocarbons from both oil and gasoline are intentionally directed to specific areas of the combustion chamber when they are present in pre-determined masses which renders them harmless. The PCV system is a controlling center of carbon gas products with limits set intentionally for high mileage operation and potentially some form of maintenance by a savvy end user, we would be the ones using paper towels and WD40 intentionally oiling up our throttle valves and compressor wheels and wiping out the intake systems, but even if we do not the engines still arrive to 200k 300k with proper general maintenance anyways, just slightly worse off, more grit in the teeth, a bit more carbon accumulation, a bit darker oil and perhaps a bit more sludgery.Probably why your better companies put fiber mat materials in the cans for the oil molecules to cling to and drain down from then??? You might want to look into Elite's systems. They claim to pull vacuum even under wot for best ring seal and crankcase scavenging. If this is true, which most independent test show it to be, then this would be better than the OE. Either way the OE has and is using catch can type devices to catch and keep oil in the engine and for it to not wind up in the combustion chambers
Bottom line here is simple. I will do # system which applies to any engine
1. Measure Crankcase pressure and establish an OEM or superior target. Generally 1.5" to 3.0" Hg crankcase pressure for all normal operations up to 1000rwhp then suffice vacuum pump as needed.
2. As part of general maintenance wipe out the intake pathways and oil your throttle valve and compressor wheel and other metal materials around the engine for protection film.
Theory vs appli.... have you not seen a toyota supra engine from 1995 arrive here in America after 200,000 miles 20 years looking brand new with a light coating of golden oil on those compressor wheels and mint bearings? And no catch can. People that install catch cans RUIN those engines. Its where I first established how PCV modifications can make thing much worse in the long terms.
Inspect these engines with varying degree of modification
They come 40 at a time with mileage from 15k to 250k miles from 1988 to 2002 from Japan to USA.
Inspect them all one at a time.
After you do this for about 1,000 times over ten years and installing them, wiring them, welding, tuning, you will realize a trend.
And that trend is that when it finally comes time to buy an engine for yourself... you will absolutely only want one that has had NO MODIFICATIONS. And that makes perfect sense now, doesn't it.
Dr. Professor in a thread about an engine he's incapable of tuning, telling everyone how catch cans don't work. Go ahead, tell everyone how it's better for this OP to rip half his sensors out and tune it in open loop. That's my favorite.
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My favorite part was when the log shows knocking at 300rpm/sec with 20* of timing you told him to increase timing and reduce the knock sensitivity. That is the worst advice Ive ever seen given on this forum. Furthermore the cherry was when you said forged pistons will 'take it'- the abuse of knocking. Which is absolute horse dog shit you have no idea how engines work, clueless about oil film thickness, and have no business tuning one.
Changing pistons to forged doesn't mean its okay to abuse them and knock an engine on purpose.
https://forum.hptuners.com/showthrea...l=1#post759873
High cylinder pressure spikes at low rpm/time rates delete oil film thickness on the upper rod bearing, leading to worn out rod bearings and catastrophic rod knocking. The engine will never make it to 50,000 miles.
Putting forged ductile aluminum pistons in an engine doesn't make it okay to knock and spike cylinder pressure. They are not intended to be knock resistant. They are only there so if you make a mistake it doesn't ruin the engine.
My engine has OEM ORIGINAL pistons for 60,000 miles at 600rwhp on 93 octane daily driver. Its the only LS engine I have ever owned and totally over 240,000 miles. My tuning is perfect. My logs are ideal. I challenge anybody to find something wrong with my logs in terms of what an ECU does: Spark and Fuel. Nobody can or will.
I'm glad you threw some numbers out there. Now that I have corrected the routing, i will have some numbers to compare with once i get some windshield time in. I'm sure every engine is different but it helps to know that getting 6-8oz out of the can is not so uncommon. So, whenever you get ready to do an oil change, (if you change it every 3k miles) are you around 3/4ths of a quart low? My next course of action is to get some seafoam to add to the oil for 100 miles or so. After that, I am going to do a leakdown test and see how that turns out. I may end up having to re-ring this thing. I thought i was pretty careful on that part and followed the manufacturers specs but there's always the possibility of mishaps.
A lot of what is accumulated in the catch can is not oil. I don't think there is a direct correlation between volume in catch can and loss of oil from the oil pan.
I see. I must have lost my oil from the push in style oil cap on the Proform valve covers. That's where my oil leak was at. After a few heat cycles, the oil cap shrinks and loosens up.
I'm not saying that it can't enter the catch can. Just under normal circumstances, I wouldn't expect all oil "lost" to be in the catch can or that everything in the catch can is oil from the oil pan.
Understood. At one point, I was consuming oil through the intake. I pulled the intake and was shocked at how the runners in the head looked. After that I re-routed the PCV hoses which was still wrong until a couple of days ago. Hopefully, things will start to shape up.
Look I'm not on here to argue or fight over this or anything else. I'm just trying to clarify some things. You said the OE didn't use catch cans. They do and even you yourself clarified that they do. There's nothing wrong with a catch can system. Yes, lots of them are garbage. Don't disagree for one sec on that. As long as it keeps the oil out of the combustion chambers and intake is all that really matters. SOME oil vapor will always make it by to lubricate like you're talking about even on the top notch systems so this will never be an issue.
What you don't seem to realize is how much oil makes it's way into via an OE system. I have literally removed intake manifolds with 100k off of 5.3l's and poured a full quart of oil out of them. This is the problem and why the OE has changed so much including adding their own catch can systems. TECHNICALLY even the valve covers could be classified as catch cans. Yes they're "baffled", but they are glued in with drain holes utilizing orifices to minimize oil ingestion. The first line of defense against this very problem.
Another aspect you're not thinking about is the tar in gasoline that once you shut off the engine is still free floating around in the air in the intake and depositing on the throttle plate and intake valves. Once you combine this with oil, well it just carbons up twice as fast. This is why induction cleans are so needed this day and time.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
The only bad way of installing a catchcan is putting in the type that has a breather. If it's sealed then it does only good. Stock size lines and about 8 inches extra length to get it routed. I mounted it to the passenger side head, so it's right there near stock provisions.
Catchcan is one of those mods that's like a cold air intake. Often done wrong because the majority of people are ignorant. How well do you think those types take care of their vehicle? Correlation vs causa...
Last edited by SiriusC1024; 12-13-2023 at 11:46 PM.
I've had their E2-X catch can setup installed since my blower install. The only thing the dual inlet can does is add a second port to the can that you connect to the intake tract pre-throttle body. Unless you are referring to a different one, there is nothing special about this dual inlet can other than an added fitting on the "clean side". This kit also includes a replacement oil fill cap that has stainless mesh in it, with a hose fitting to also connect to the intake tract for a secondary avenue for crankcase gases to get pulled out, and to provide fresh air into the crankcase when not under boost. 2 check valves are included to install in the appropriate places for boosted applications. For what it is worth, I measured up to 6 kpa crankcase pressure at 8 lbs boost with this setup. Since then I have pulled the pcv connector out of the left rear valve cover and drilled it out (from 1/8 to 3/8"), installed the expensive ME Wagner adjustable pcv valve, put a larger fitting in the intake tract, and max crankcase pressure is now around 1-2 kpa. Still could be better. Measured with a GM MAP sensor, signal fed into a MVPI1 Pro analog input. After drilling out the valve cover connector, I tried a stock pcv valve (unknown application) between the catch can and manifold vac port, but it was not pulling vac on the crankcase in part throttle conditions. Good luck finding any flow data to pick an appropriate pcv valve. This is why I went with the ME Wagner, it gives you an adjustment for idle and part throttle, then acts as a check valve under boost (they only tested to 20 psi for you big HP guys).
I had the need to pull the blower back off shortly after installing it for injectors (few hundred miles?), and there was still some oil puddling in the lower intake. Never took any measurements, but usually only got a couple tablespoons after a few hundred miles. In the wintertime on E85, the catch can would trap a bunch of condensate/oil sludge, very nasty.
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