Catch Can Air Flow!
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Joined: 01-05-12
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From: Brenham TX
I actually misread your post about the catch can, hence why I made the comment about VC to turbo.
also just a heads up, it's a bad idea to insult your potential customers. Is this how you run your business?
also just a heads up, it's a bad idea to insult your potential customers. Is this how you run your business?
Last edited by DPveritasGold; Jul 30, 2012 at 11:29 AM. Reason: left out information
I put a lot of effort time and money into developing things, and spend probably too much time on these forums answering questions for folks that dont search. But I specifically pointed out to you in your thread that the fresh air inlet is NOT the place to put a catch can.
If I lost you as a customer over this? I guess I could say I am sorry.
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Joined: 01-05-12
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From: Brenham TX
Probably best just to drop this whole issue. But for the record I don't know why you thought that I wanted to put the can between the fresh air source and the valve cover. My question was about how the air flows between the VC and the turbo not the fresh air source to the VC.
Anyhow, it's not a big deal, if I'm ever looking for a product for my car and Powell truly has the best part, I wouldn't hesititate to buy it. Like I said, no big deal.
Anyhow, it's not a big deal, if I'm ever looking for a product for my car and Powell truly has the best part, I wouldn't hesititate to buy it. Like I said, no big deal.
If "lol" insults you, too bad. I could have said "reading impaired". I did not.
I put a lot of effort time and money into developing things, and spend probably too much time on these forums answering questions for folks that dont search. But I specifically pointed out to you in your thread that the fresh air inlet is NOT the place to put a catch can.
If I lost you as a customer over this? I guess I could say I am sorry.
I put a lot of effort time and money into developing things, and spend probably too much time on these forums answering questions for folks that dont search. But I specifically pointed out to you in your thread that the fresh air inlet is NOT the place to put a catch can.
If I lost you as a customer over this? I guess I could say I am sorry.
, I'm genuinely interested in what you've came up with as you've stated many times upon my research that a catchcan on an LNF is silly. I am curious as to the solution here, as I've actually uninstalled my MPx catchcan and do have concern about gunk buildup 
.
Oh John I did not , I'm genuinely interested in what you've came up with as you've stated many times upon my research that a catchcan on an LNF is silly. I am curious as to the solution here, as I've actually uninstalled my MPx catchcan and do have concern about gunk buildup .
, I'm genuinely interested in what you've came up with as you've stated many times upon my research that a catchcan on an LNF is silly. I am curious as to the solution here, as I've actually uninstalled my MPx catchcan and do have concern about gunk buildup .there is a vent tube with an internal orifice on the dirty side, it vents to the turbo on the intake side.
catch cans without a seperator in two chambers really just become an accumulator of oil.
the idea is for the oil laden air on the dirty side to pass through the media ( or spill plates) so the air can leave the oil behind and then be sent on to the original routing.
Then the question is, what to do with the accumulated oil? it needs a place to go, and draining it after every track session or every week on the street onto your driveway or into a plastic bottle is not a good way to do it. I have a way and it makes the system better, while preserving the stock PCV opertion which is very important. If you vent the pcv to atmosphere with a filter like a hot rod vent cap, all bets are off and the pcv system will not work well at all.
The pcv orifice sizes (there is more than one ) are chosen to keep the crankcase pressure negative by a small amount under all operating conditions.
Under light load, the turbo inlet venturi effect is just enough to cause a depression and pull air through the crankcase from the fresh clean air duct tube. The check valve becomes an orifice to control depression.
Under high load where the piston blow-by becomes significant, the fresh passage is stopped with a check valve. This is to prevent back flow. The venturi effect of the turbocharger inlet is sufficient to pull in 100% of the piston blow by, plus pull the crankcase pressure 2 to 3 kPa .
where it starts to fall apart , is when the gradual build up of coked oil on the inlet valves starts to inhibit proper engine operation, and it becomes a circle jerk; the more build up the more oil gets kicked through the pcv, the more oil, the more build up etc. Also if there is an aftermarket tune, and there is a lot more fuel, timing and combustion pressure being thrown at the motor, it is possible that the piston rings and ring lands and skirts will wear really fast and then blowby (pressure in the crankcase) becomes so great the pcv system just cant deal with it.
As an aside, I have pulled LNF pistons at low mileage that look like trash. LSJ pistons over 50 miles, the skirts look brand new, running similar boost levels..,( 22 psi)
Inlet valve temperature is another issue, and like I have said many times, no one thing will fix this issue, driving cycles and low ash oil are both important factors to consider.
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From: A.B.E. PA & Jacksonville FL
a catchcan on the fresh air side is silly. There is a check valve in it (thats the orifice) and it lets air in to the engine. There is another check valve in the inlet manifold, so the engine on vacuum ( off boost) can breathe fumes into the inlet manifold. The check valve there closes the moment the inlet is not pulling vacuum.
there is a vent tube with an internal orifice on the dirty side, it vents to the turbo on the intake side.
catch cans without a seperator in two chambers really just become an accumulator of oil.
the idea is for the oil laden air on the dirty side to pass through the media ( or spill plates) so the air can leave the oil behind and then be sent on to the original routing.
Then the question is, what to do with the accumulated oil? it needs a place to go, and draining it after every track session or every week on the street onto your driveway or into a plastic bottle is not a good way to do it. I have a way and it makes the system better, while preserving the stock PCV opertion which is very important. If you vent the pcv to atmosphere with a filter like a hot rod vent cap, all bets are off and the pcv system will not work well at all.
The pcv orifice sizes (there is more than one ) are chosen to keep the crankcase pressure negative by a small amount under all operating conditions.
Under light load, the turbo inlet venturi effect is just enough to cause a depression and pull air through the crankcase from the fresh clean air duct tube. The check valve becomes an “orifice” to control depression.
Under high load where the piston blow-by becomes significant, the fresh passage is stopped with a check valve. This is to prevent back flow. The venturi effect of the turbocharger inlet is sufficient to pull in 100% of the piston blow by, plus pull the crankcase pressure 2 to 3 kPa .
where it starts to fall apart , is when the gradual build up of coked oil on the inlet valves starts to inhibit proper engine operation, and it becomes a circle jerk; the more build up the more oil gets kicked through the pcv, the more oil, the more build up etc. Also if there is an aftermarket tune, and there is a lot more fuel, timing and combustion pressure being thrown at the motor, it is possible that the piston rings and ring lands and skirts will wear really fast and then blowby (pressure in the crankcase) becomes so great the pcv system just cant deal with it.
As an aside, I have pulled LNF pistons at low mileage that look like trash. LSJ pistons over 50 miles, the skirts look brand new, running similar boost levels..,( 22 psi)
Inlet valve temperature is another issue, and like I have said many times, no one thing will fix this issue, driving cycles and low ash oil are both important factors to consider.
there is a vent tube with an internal orifice on the dirty side, it vents to the turbo on the intake side.
catch cans without a seperator in two chambers really just become an accumulator of oil.
the idea is for the oil laden air on the dirty side to pass through the media ( or spill plates) so the air can leave the oil behind and then be sent on to the original routing.
Then the question is, what to do with the accumulated oil? it needs a place to go, and draining it after every track session or every week on the street onto your driveway or into a plastic bottle is not a good way to do it. I have a way and it makes the system better, while preserving the stock PCV opertion which is very important. If you vent the pcv to atmosphere with a filter like a hot rod vent cap, all bets are off and the pcv system will not work well at all.
The pcv orifice sizes (there is more than one ) are chosen to keep the crankcase pressure negative by a small amount under all operating conditions.
Under light load, the turbo inlet venturi effect is just enough to cause a depression and pull air through the crankcase from the fresh clean air duct tube. The check valve becomes an “orifice” to control depression.
Under high load where the piston blow-by becomes significant, the fresh passage is stopped with a check valve. This is to prevent back flow. The venturi effect of the turbocharger inlet is sufficient to pull in 100% of the piston blow by, plus pull the crankcase pressure 2 to 3 kPa .
where it starts to fall apart , is when the gradual build up of coked oil on the inlet valves starts to inhibit proper engine operation, and it becomes a circle jerk; the more build up the more oil gets kicked through the pcv, the more oil, the more build up etc. Also if there is an aftermarket tune, and there is a lot more fuel, timing and combustion pressure being thrown at the motor, it is possible that the piston rings and ring lands and skirts will wear really fast and then blowby (pressure in the crankcase) becomes so great the pcv system just cant deal with it.
As an aside, I have pulled LNF pistons at low mileage that look like trash. LSJ pistons over 50 miles, the skirts look brand new, running similar boost levels..,( 22 psi)
Inlet valve temperature is another issue, and like I have said many times, no one thing will fix this issue, driving cycles and low ash oil are both important factors to consider.
i remember a customer late last year actually wanted to change his piston rings [he later confirmed to us he did a leak down test after the fact], later to find the rings weren't at spec and the cyl walls did have some "scoring".. he did have mild tune and some coking on the valves [09 SS/TC], replaced rings, honed cyl walls, performed leak down - ok, but did find vacuum/pressure would go up and down depending on the line dia he had on his catch can.. not 100% sure but i think it was a 7mm and 5 or 6mm line he had..
could it be - the dia size of the lines [vac/breather line] could play an important role?
Last edited by gone_in_10_sec; Jul 31, 2012 at 03:30 PM.
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From: Tejas
John - interesting, i wonder how the "return" oil works and is it used as a "baffling" effect?
i remember a customer late last year actually wanted to change his piston rings [he later confirmed to us he did a leak down test after the fact], later to find the rings weren't at spec and the cyl walls did have some "scoring".. he did have mild tune and some coking on the valves [09 SS/TC], replaced rings, honed cyl walls, performed leak down - ok, but did find vacuum/pressure would go up and down depending on the line dia he had on his catch can.. not 100% sure but i think it was a 7mm and 5 or 6mm line he had..
could it be - the dia size of the lines [vac/breather line] could play an important role?
i remember a customer late last year actually wanted to change his piston rings [he later confirmed to us he did a leak down test after the fact], later to find the rings weren't at spec and the cyl walls did have some "scoring".. he did have mild tune and some coking on the valves [09 SS/TC], replaced rings, honed cyl walls, performed leak down - ok, but did find vacuum/pressure would go up and down depending on the line dia he had on his catch can.. not 100% sure but i think it was a 7mm and 5 or 6mm line he had..
could it be - the dia size of the lines [vac/breather line] could play an important role?
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Joined: 10-05-10
Posts: 805
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From: A.B.E. PA & Jacksonville FL
Well, what's the diameter of the size of the short pipe coming out of the VC that the stock hose connects to that goes to the turbo? Are we saying that there might be some benefit to enlarging it beyond its stock size, or using some other better ventilating approach (such as where the oil cap goes)?
i can seen enlarging the breather line..
but the positive benefits could be either increase air/vacuum into the system [which can either decrease blow-by at the rings and increase in boost
] or
the negative benefits could be either decrease air/vacuum into the system [which can either increase blow-by at the rings and decrease in boost
] until someone tries the theory, no one really knows..
I understand that line diameter plays an important role, but to what degree does it affect the system as a whole?
Well, what's the diameter of the size of the short pipe coming out of the VC that the stock hose connects to that goes to the turbo? Are we saying that there might be some benefit to enlarging it beyond its stock size, or using some other better ventilating approach (such as where the oil cap goes)?
etc.
The whole idea ( at least mine ) is NOT to vent to atmosphere, to keep it a closed pcv system, enabling it to deal with higher levels of crankcase blow by than GM counted on so the engine runs as intended, and does not fail smog inspection etc., and most importantly combined with good fuel, low ash motor oil and a better individual driving cycle, to avoid coking of the valves...
John - interesting, i wonder how the "return" oil works and is it used as a "baffling" effect?
i remember a customer late last year actually wanted to change his piston rings [he later confirmed to us he did a leak down test after the fact], later to find the rings weren't at spec and the cyl walls did have some "scoring".. he did have mild tune and some coking on the valves [09 SS/TC], replaced rings, honed cyl walls, performed leak down - ok, but did find vacuum/pressure would go up and down depending on the line dia he had on his catch can.. not 100% sure but i think it was a 7mm and 5 or 6mm line he had..
could it be - the dia size of the lines [vac/breather line] could play an important role?
i remember a customer late last year actually wanted to change his piston rings [he later confirmed to us he did a leak down test after the fact], later to find the rings weren't at spec and the cyl walls did have some "scoring".. he did have mild tune and some coking on the valves [09 SS/TC], replaced rings, honed cyl walls, performed leak down - ok, but did find vacuum/pressure would go up and down depending on the line dia he had on his catch can.. not 100% sure but i think it was a 7mm and 5 or 6mm line he had..
could it be - the dia size of the lines [vac/breather line] could play an important role?
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Joined: 10-05-10
Posts: 805
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From: A.B.E. PA & Jacksonville FL
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