Clearing up misconceptions of PCV systems
09-01-2008, 12:38 PM
#61
I would like to detail a few items that will be of interest to those reading this thread.
1) Cars with SD tunes can use valve cover breathers without causing PCM issues.
2) Cars can use valve cover breathers without causing PCM issues as long as the crank case is not vented to the intake. For example, for those with LS6 valley covers, either seal off the PCV nipple or install a PCV valve so that air cannot be sucked into the crank case & then hook the line up to an external catch can vented to atmosphere.
3) Cars using PCV systems connected to the intake cannot use un-measured air (valve cover breathers) without causing fuel trim issues. So, in this case, measured air run from the throttle body to the valve covers is required.
1) Cars with SD tunes can use valve cover breathers without causing PCM issues.
2) Cars can use valve cover breathers without causing PCM issues as long as the crank case is not vented to the intake. For example, for those with LS6 valley covers, either seal off the PCV nipple or install a PCV valve so that air cannot be sucked into the crank case & then hook the line up to an external catch can vented to atmosphere.
3) Cars using PCV systems connected to the intake cannot use un-measured air (valve cover breathers) without causing fuel trim issues. So, in this case, measured air run from the throttle body to the valve covers is required.
09-01-2008, 02:51 PM
#62
I would like to detail a few items that will be of interest to those reading this thread.
1) Cars with SD tunes can use valve cover breathers without causing PCM issues.
2) Cars can use valve cover breathers without causing PCM issues as long as the crank case is not vented to the intake. For example, for those with LS6 valley covers, either seal off the PCV nipple or install a PCV valve so that air cannot be sucked into the crank case & then hook the line up to an external catch can vented to atmosphere.
The engine needs a vacume source to pull out the harmful vapors or long term damage will occur.....as you described all that is accomplished like that is venting excess pressure, no flushing.
3) Cars using PCV systems connected to the intake cannot use un-measured air (valve cover breathers) without causing fuel trim issues. So, in this case, measured air run from the throttle body to the valve covers is required.
1) Cars with SD tunes can use valve cover breathers without causing PCM issues.
2) Cars can use valve cover breathers without causing PCM issues as long as the crank case is not vented to the intake. For example, for those with LS6 valley covers, either seal off the PCV nipple or install a PCV valve so that air cannot be sucked into the crank case & then hook the line up to an external catch can vented to atmosphere.
The engine needs a vacume source to pull out the harmful vapors or long term damage will occur.....as you described all that is accomplished like that is venting excess pressure, no flushing.
3) Cars using PCV systems connected to the intake cannot use un-measured air (valve cover breathers) without causing fuel trim issues. So, in this case, measured air run from the throttle body to the valve covers is required.
09-01-2008, 08:21 PM
#63
The amount of air if a proper valve is used to restrict the amount of vacume pulled is not enough to cause problems in most cases, but to be sure you can always tune it after the install of a system bypassing the TB as the fresh-air source. We sell 50 plus of these a week w/no issues to date as far as unmetered air.
Yah, I thought that you might take issue with #2. I noted it because guys do it; even though it's not the correct way. Your revision of #2 is correct (for archive reference).
Regarding the amount of vacuum pulled; In an effort to continue to note valid findings related to the PCV vacuum, earlier in this thread I noted the STFT changes that the added (non-measured) air caused on my car. The Short Term Fuel Trims went from a normal -3 to 0 (@ idle) to max (on my car 15%) because of the vacuum air added to the intake. This was when valve cover filters were used as an external air source (non-measured air on a MAF system) & the PCV was vented to the intake. When the filters were removed & MAF measured air was used to feed the valve covers, the STFT's returned to normal.
I agree that tuning can return the STFT's to normal when external valve cover filters are used. I also feel that it is important for owners to know that by adding valve cover filters, their short term fuel trims are likely maxed out & over a short time this will also increase the Long Term Fuel Trims (if not re-tuned). What does this mean; nothing unless the engine reaches a lean condition & then can't be corrected by the fuel trims. Most likely @ freeway speeds in 5th or 6th gear when trying to accelerate, the timing @ the lower RPM's is higher, the fueling will lean out with no way to correct it, & engine knock will occur until the knock sensors reduce it. Owners should realize this. I wouldn't expect WOT pulls in first or second to be an issue because PE should take care of the fueling as long as the MAF table is correct. Again, am noting this as information that is helpful to the thread.
09-02-2008, 08:33 AM
#64
Yah, I thought that you might take issue with #2. I noted it because guys do it; even though it's not the correct way. Your revision of #2 is correct (for archive reference).
Regarding the amount of vacuum pulled; In an effort to continue to note valid findings related to the PCV vacuum, earlier in this thread I noted the STFT changes that the added (non-measured) air caused on my car. The Short Term Fuel Trims went from a normal -3 to 0 (@ idle) to max (on my car 15%) because of the vacuum air added to the intake. This was when valve cover filters were used as an external air source (non-measured air on a MAF system) & the PCV was vented to the intake. When the filters were removed & MAF measured air was used to feed the valve covers, the STFT's returned to normal.
I agree that tuning can return the STFT's to normal when external valve cover filters are used. I also feel that it is important for owners to know that by adding valve cover filters, their short term fuel trims are likely maxed out & over a short time this will also increase the Long Term Fuel Trims (if not re-tuned). What does this mean; nothing unless the engine reaches a lean condition & then can't be corrected by the fuel trims. Most likely @ freeway speeds in 5th or 6th gear when trying to accelerate, the timing @ the lower RPM's is higher, the fueling will lean out with no way to correct it, & engine knock will occur until the knock sensors reduce it. Owners should realize this. I wouldn't expect WOT pulls in first or second to be an issue because PE should take care of the fueling as long as the MAF table is correct. Again, am noting this as information that is helpful to the thread.
Regarding the amount of vacuum pulled; In an effort to continue to note valid findings related to the PCV vacuum, earlier in this thread I noted the STFT changes that the added (non-measured) air caused on my car. The Short Term Fuel Trims went from a normal -3 to 0 (@ idle) to max (on my car 15%) because of the vacuum air added to the intake. This was when valve cover filters were used as an external air source (non-measured air on a MAF system) & the PCV was vented to the intake. When the filters were removed & MAF measured air was used to feed the valve covers, the STFT's returned to normal.
I agree that tuning can return the STFT's to normal when external valve cover filters are used. I also feel that it is important for owners to know that by adding valve cover filters, their short term fuel trims are likely maxed out & over a short time this will also increase the Long Term Fuel Trims (if not re-tuned). What does this mean; nothing unless the engine reaches a lean condition & then can't be corrected by the fuel trims. Most likely @ freeway speeds in 5th or 6th gear when trying to accelerate, the timing @ the lower RPM's is higher, the fueling will lean out with no way to correct it, & engine knock will occur until the knock sensors reduce it. Owners should realize this. I wouldn't expect WOT pulls in first or second to be an issue because PE should take care of the fueling as long as the MAF table is correct. Again, am noting this as information that is helpful to the thread.
You are correct. We do find that with the proper PCV check valve that it has been a managable amount, but pulling the fresh air from the inlet (after main air filter as the TB fitting does) is as you point out the most precise way to insure STFT's are not maxed out. Pulling directly to the intake if the amount is not controlled will result in a lean condition. Thanks for the contribution!
09-02-2008, 12:21 PM
#66
Try local salvage yards. If not there, try on-line salvage yards that specialize in LS1's. Should be able to find one cheap. You can also make your own.
09-12-2008, 08:51 AM
#67
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nice
exactly what i was looking for.
jesus christ.. that has to be an interesting driver. I bet that will haze the tires off 1-6th.whats that weigh?
exactly what i was looking for.
1999 LS6 MIATA, 2006 LS6 block, AFR 205 heads, baby Comp cam, 1.8 rockers, ported Weiand, 85mm TB, 85mm MAF, Melling, ASP, A/C, PS, long tubes, true duals, D&D performance GM Viper T56, Spec 3+, UMI/Cobra short stick & ****, 3.55's & Detroit True-Trac in a Ford 8.8, KYB AGX's, sub-frame bracing, 4 point roll bar, harnesses, C4 Corvette brakes...PLX WB02, EFI Live, 98 PCM...396 g/s @ 101 kPa, 650 CFM...How Gay does it look from behind?
Last edited by RX666; 09-21-2008 at 10:43 AM.
12-17-2009, 01:08 PM
#70
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ok i have a 383 stroker Ls1 with 11.5 to 1 compression and its goin to have a 200 shot. I have an ls6 valley cover on it but my question is, I have aftermarket taller valve covers with no pcv previsions, so if I run a breather in the oil cap can i just run a rev xtreme catch can and how do i need to route it. i havent found any good pics or direct explanations in searching for my specific case. thanks for the help
12-17-2009, 03:35 PM
#71
Here's, finally, the cure and end all to the oil ingestion and blow-by of sprayed cars as well as blowers/turbos. I guess even the n/a cars could benefit as a stocker can have an intake filled with oil, ask me how I know, lol.
The Vacuum pump can free up some ponies too. Some have reported 40/50hp gains, IIRC. I mounted the puke tank forward of the radiator, on the frame rail, then plumbed and tied up a remote drain line and pet-****. So now I can drain the oil when needed from under the front frame rail area. The pump is designed to use the oil mist as lube on the internal blades and thus making it a long lasting street/strip part. Pumps of old would not last more than a few hundred miles, but this style will. I have numerous pictures for a write-up/how-to if anyone is intrested in seeing the details.
Also, no need to worry about having to much vacuum and pulling oil from the piston pins, a non issue. The kit I used has an adjustable valve to limit vac created. If we keep it under 15kpa, the LSx platform can live a long normal life. They have thousands out in the feild with no issues. Pumps of old would suck the oil from the pins and cause failures. A good engineered piece will not.
I am sold, as we have tried every other trick mentioned and then some. We don't want oil in the combustion chamber of a motor spraying 300 and bigger shots, not to mention a 100shot.
Robert
The Vacuum pump can free up some ponies too. Some have reported 40/50hp gains, IIRC. I mounted the puke tank forward of the radiator, on the frame rail, then plumbed and tied up a remote drain line and pet-****. So now I can drain the oil when needed from under the front frame rail area. The pump is designed to use the oil mist as lube on the internal blades and thus making it a long lasting street/strip part. Pumps of old would not last more than a few hundred miles, but this style will. I have numerous pictures for a write-up/how-to if anyone is intrested in seeing the details.
Also, no need to worry about having to much vacuum and pulling oil from the piston pins, a non issue. The kit I used has an adjustable valve to limit vac created. If we keep it under 15kpa, the LSx platform can live a long normal life. They have thousands out in the feild with no issues. Pumps of old would suck the oil from the pins and cause failures. A good engineered piece will not.
I am sold, as we have tried every other trick mentioned and then some. We don't want oil in the combustion chamber of a motor spraying 300 and bigger shots, not to mention a 100shot.
Robert
12-17-2009, 04:31 PM
#72
Here's, finally, the cure and end all to the oil ingestion and blow-by of sprayed cars as well as blowers/turbos. I guess even the n/a cars could benefit as a stocker can have an intake filled with oil, ask me how I know, lol.
The Vacuum pump can free up some ponies too. Some have reported 40/50hp gains, IIRC. I mounted the puke tank forward of the radiator, on the frame rail, then plumbed and tied up a remote drain line and pet-****. So now I can drain the oil when needed from under the front frame rail area. The pump is designed to use the oil mist as lube on the internal blades and thus making it a long lasting street/strip part. Pumps of old would not last more than a few hundred miles, but this style will. I have numerous pictures for a write-up/how-to if anyone is intrested in seeing the details.
Also, no need to worry about having to much vacuum and pulling oil from the piston pins, a non issue. The kit I used has an adjustable valve to limit vac created. If we keep it under 15kpa, the LSx platform can live a long normal life. They have thousands out in the feild with no issues. Pumps of old would suck the oil from the pins and cause failures. A good engineered piece will not.
I am sold, as we have tried every other trick mentioned and then some. We don't want oil in the combustion chamber of a motor spraying 300 and bigger shots, not to mention a 100shot.
Robert
The Vacuum pump can free up some ponies too. Some have reported 40/50hp gains, IIRC. I mounted the puke tank forward of the radiator, on the frame rail, then plumbed and tied up a remote drain line and pet-****. So now I can drain the oil when needed from under the front frame rail area. The pump is designed to use the oil mist as lube on the internal blades and thus making it a long lasting street/strip part. Pumps of old would not last more than a few hundred miles, but this style will. I have numerous pictures for a write-up/how-to if anyone is intrested in seeing the details.
Also, no need to worry about having to much vacuum and pulling oil from the piston pins, a non issue. The kit I used has an adjustable valve to limit vac created. If we keep it under 15kpa, the LSx platform can live a long normal life. They have thousands out in the feild with no issues. Pumps of old would suck the oil from the pins and cause failures. A good engineered piece will not.
I am sold, as we have tried every other trick mentioned and then some. We don't want oil in the combustion chamber of a motor spraying 300 and bigger shots, not to mention a 100shot.
Robert
Looks nice, but the magical question is HOW MUCH?
12-17-2009, 04:40 PM
#73
IIRC, about $800.00, however, I got the big one and all the extras. The Sportsman base kit is $430.00. You can delete things like puke can and hoses, go down one size... But man, the way I look at it, if it saves my motor from grenading on the spray from ingested oil, then it is good insurance money. I like to think of it as an investment. They are rebuild-able, so they can stay when going to a new motor or different car. Also, don't forget there is an instant HP gain too.
Robert
Robert
12-17-2009, 05:14 PM
#74
IIRC, about $800.00, however, I got the big one and all the extras. The Sportsman base kit is $430.00. You can delete things like puke can and hoses, go down one size... But man, the way I look at it, if it saves my motor from grenading on the spray from ingested oil, then it is good insurance money. I like to think of it as an investment. They are rebuild-able, so they can stay when going to a new motor or different car. Also, don't forget there is an instant HP gain too.
Robert
Robert
12-17-2009, 05:23 PM
#75
I think it's alright to post the company as they are the only ones doing this that i know of, so it wouldn't comprimise any of the vendors here, right, lol? Or maybe a vendor here carries this line? I have a write-up/how-to I did, but need to get it in to PDF so I can post it. Some cry when I link my site, besides I took it off my site for now. GZ Motorsports is the company that makes em.
Robert
Robert
12-18-2009, 03:32 AM
#77
With a filter on the fill spout you can mount your puke tank where ever you like. They don't work so well and many Vette guys run two back to back. There are numerous threads showing the lay outs as there are a couple variations. Search is your freind.
Robert
Robert
12-20-2009, 01:10 AM
#78
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search was not my friend as i did not find an exact answer to my question/\. im not a noob i know to search lol thats how i dug up this old thread
12-20-2009, 01:47 AM
#79
Here is a link I saved that may have the plumbing, if not let me know as I have numerous other catch can threads, with good stuff like that trick catch can below.
https://ls1tech.com/forums/forced-induction/734113-pvc-catch-can-system-final-conclusive-answer.html
Robert
12-20-2009, 10:10 AM
#80
is my pvc system setup right or wrong?This is a procharged ls2 car my fresh air,I tap into the inlet hat after the filter,t/b is capped off all the ports on the valve covers are capped off I have a rev catch can and I run the from the valley cover with a chk valve to the bottom of the can and the top of it to the fast intake.I was wondering do I need a breather on one of the valve covers? thanks