View Full Version : Is a PCV Oil Catch can necessary on LS engines?
GeoffP
03-14-2012, 05:08 PM
I have noticed several people have installed catch cans in the PCV circuit on their LS engine. How necessary are these? I understand the purpose but don't want or need the expense if it's going to save me a bottle of oil every oil change. $80-100 is steep compared to a $6-7 qt bottle of Mobile 1. It takes a LOT of oil to pay for that expense.
Chris02rex
03-14-2012, 05:13 PM
Its more for keeping the oil out of your intake. I believe they are more necessary on a turbo vehicle rather than on a na car. I may be wrong though haha.
LS1-IROC
03-16-2012, 12:28 PM
Are they absolutely necessary...no..are they a good idea, you bet. If you have ever looked inside a LS intake that's been run without one, you'd wish you would have spent the money on one.
GeoffP
03-16-2012, 02:57 PM
Thanks for the info guys!
Are they absolutely necessary...no..are they a good idea, you bet. If you have ever looked inside a LS intake that's been run without one, you'd wish you would have spent the money on one.
he is correct the LS intake fills with oil about an 1/16 to an 1/8 of a quart about every 3-4 weeks, most of it passes into the engine and is burned during combustion, injected or carbureted its about the same, the Gen 1 SBC does the same thing
dontlifttoshift
03-17-2012, 09:29 AM
I really expected there to be more action on this thread.
Is the factory PCV system so aggressive that literally sucks the oil out of the valve covers and into the intake? Even with factory baffled covers? I ran lines from both covers to fresh air in the intake tube, does that help at all?
GeoffP
03-19-2012, 04:05 AM
Rodney - I'm afraid I'm going to have to disagree with your statement about Gen 1 small blocks doing the same thing. I have had many of them over the years and never had one suck oil into the intake. Of course this statement comes with the caveat that they were in good running condition. Both SBC's I had that were in bad running condition burned so much oil that it was hard to tell where it was coming from and where it was going! The only other SBC I've owned that used oil was a new engine that used oil until it was broken in good (which is what I consider normal). It's the engine that's in my truck right now and doesn't use a drop of oil now that it has about 14,000 mi on it (new GM engine).
Having said all that I am curious why the Gen III's and Gen IV's are pulling oil into the intake so much that a catch can is recommended. I agree that they do use oil because my wife's Tahoe has always lost about a quart between oil changes and my co-worker's new 2010 truck uses anywhere from a quart to 3 quarts between oil changes. He suspects the PCV system so this thread, IMHO, confirms that suspicion. Apparently GM is aware there's a problem because a friend of his had a similar truck with a similar problem. GM replaced a "circulation valve" that stopped the excessive oil consumption completely.
However, I'm surprised there hasn't been more stink about this publicly because it's obviously a design problem that needs to be fixed (without a catch can). I may have to see if I can find out what the revised valve is so I can use one on my engine build - I hate the thought of a catch can in line with the PCV system. Plus, most of the ones I've seen a just plain ugly (and expensive).
SparkyRnD
03-22-2012, 07:16 PM
sometimes they can look not so bad:
https://static1.pt-content.com/images/pt/2011/12/CatchRound1-1.jpg
your right Geoff, lot of SBC motors hardly use a drop after break-in, I do know that the race engines we build(drag engines), some burn serious oil, but we change oil and plugs after only a few runs, my old daily driver/race motor was a 383 with .80 pistons and the bearing tolerances were very loose (clattered a little on start up) and it burned about a quart between oil changes, the plugs were at the edge of foul at every 3000 mile oil/plug change and after the first season of racing we built an oil-air separator with the help of a larger manufacture and the plugs could have ran double the life without foul, its not really a design flaw LS engine burn mostly on decel and works as a top end cylinder lubricant and adds longevity to the motors, (so I have been told)
69cutlassrkt
03-23-2012, 06:18 AM
Are there any cons to deleting the pcv and running a breather?
Are there any cons to deleting the pcv and running a breather?
not really, there could be some blow-by through the breather from block pressure, could get the valve covers/ engine compartment a little dirty
GeoffP
03-25-2012, 01:17 PM
Sparky - is that a can that you make?
BuzzKillian
03-25-2012, 03:01 PM
Would sombody post some pictures of their tank installed.... this is first I have heard of this.
martZ
03-26-2012, 09:22 AM
http://www.mikenorrismotorsports.com/Billet_PCV_Catch_Cans.html
Lots of pictures. Sponsor of this site.
BuddyP
03-26-2012, 05:55 PM
I've been kinda oblivious to the whole PCV setup until now, which sucks because basically my valve covers are pretty much worthless and now I have to spend a whole lot more $$ on a PCV system and fittings/valve covers.
What I really want to know is:
1. Can I just pull off one valve cover?
2. Does a tube need to be run between the throttle body and valve cover?
3. How would I plumb in the catch can? (Keep in mind I have a truck block so my valley cover has no PCV provision)
parsonsj
03-26-2012, 06:12 PM
Are there any cons to deleting the pcv and running a breather?Yes. The PCV system pulls dirty acidic vapor from the crankcase and burns it, while pulling fresh clean air to replace it. PCV systems are the main reason modern engines last so much longer than our old original engines. There's no good reason not to run one -- it doesn't cost any power, it reduces pressure on your gaskets and seals, and it improves your engine's lifespan.
parsonsj
03-26-2012, 06:24 PM
Here's a good discussion of PCV:
http://forum.diyefi.org/viewtopic.php?f=24&t=357
scherp69
03-26-2012, 06:54 PM
I've been kinda oblivious to the whole PCV setup until now, which sucks because basically my valve covers are pretty much worthless and now I have to spend a whole lot more $$ on a PCV system and fittings/valve covers.
What I really want to know is:
1. Can I just pull off one valve cover?
2. Does a tube need to be run between the throttle body and valve cover?
3. How would I plumb in the catch can? (Keep in mind I have a truck block so my valley cover has no PCV provision)
Buddy..I ended up buying a catch can from Mike Norris Motorsports http://www.mikenorrismotorsports.com/Billet_PCV_Catch_Cans.html Mike's been very helpful in helping me answer how I'm going to run mine. Since my valley cover didn't have a PCV tube on it, I picked up one from ebay for $15.95 plus shipping. I'm going to run one tube to that tube and the other will go to the outlet on the intake just behind the throttle body. Hope that helps.
SparkyRnD
03-26-2012, 07:31 PM
Sparky - is that a can that you make? Yes, we make them for $90 for PT members ($100 retail). That is an overflow catch can, but we can build them for oil, water, et cetera, and can put whatever fittings someone wants (a slight up-charge depending on the fittings)
BuddyP
03-28-2012, 05:30 AM
Buddy..I ended up buying a catch can from Mike Norris Motorsports http://www.mikenorrismotorsports.com/Billet_PCV_Catch_Cans.html Mike's been very helpful in helping me answer how I'm going to run mine. Since my valley cover didn't have a PCV tube on it, I picked up one from ebay for $15.95 plus shipping. I'm going to run one tube to that tube and the other will go to the outlet on the intake just behind the throttle body. Hope that helps.
LS3 or LS6 cover? The LS3 cover doesn't have knock sensors. Don't know if I need them or not but my harness is hooked up ot them.
scherp69
03-28-2012, 08:13 AM
LS3 or LS6 cover? The LS3 cover doesn't have knock sensors. Don't know if I need them or not but my harness is hooked up ot them.
LS3. Here's a link to the ebay ad: http://www.ebay.com/itm/2010-2011-Chevy-Camaro-SS-LS3-L99-Intake-Valley-Cover-/220982995503?pt=Motors_Car_Truck_Parts_Accessories&hash=item33739cea2f&vxp=mtr
Here's the one I got
https://static1.pt-content.com/images/pt/2012/03/P1010428-1.jpg
diesel25lrs
04-04-2012, 02:14 PM
Does the new LS3 have this same issue? I'm hooking mine up right now and wondering if I need a can?
GeoffP
04-05-2012, 04:40 AM
Tom Farrington has one on his car and his engine is an LS3 clone so I'd say the answer to that is yes.
GeoffP
04-22-2012, 05:03 AM
I did my PCV setup yesterday. I put an On3Performance oil catch can in line to the intake to help with any oil issues. It's a nice piece though they put bigger fittings on it than needed. I was able to work around the fittings though. I plumbed the majority of the lines with 3/8" steel line. It turned out pretty nice though the 180* bend out of the catch can could look better. I may redo it later but it's good enough for now. Also, I found out that early LS engines used a PCV valve so I put one in. The baffling in the valve and the catch can should keep any oil out of the intake. Thanks for everyone's input!
diesel25lrs
04-22-2012, 06:30 AM
Any pics?
GeoffP
04-22-2012, 07:23 PM
Not yet - I'm buttoning up the wiring so it'll be a couple days, but I promise I will post pics in my build thread.
Slick68
04-27-2012, 04:17 PM
How hard would it be to build a baffle system under the valley pan on an early GenIII? I'm building an LS1. I'm also going carbureted on it. I made my own valley pan out of 1/4" sheet aluminum. If a baffle system could be made or modified, it should be fairly simple to add to the valley pan.
I may look into the catch can idea, though for my application as I intend to run the PVC off the valve cover.
Chad-1stGen
04-27-2012, 04:23 PM
Where does the PCV valve go on an LS3? I see pics of nipples off of both the valley cover and valve covers. Is it an inline PCV valve?
GeoffP
04-27-2012, 04:51 PM
Based on my research and the help of a forum member there's an orifice inline on the LS3. I used a PCV valve on my engine.
dontlifttoshift
04-27-2012, 05:10 PM
There is not a pcv valve.....at least not as we know it. There is a hose or line that connects the intake to the valley cover on the passenger side near the throttle body. There is a nipple out of the passenger side valve cover that points forward. The nipple has a .105" id and that gets hooked to the air filter, that is the fresh air intake for the engine.
It's essentially a controlled vacuum leak.
Cris@JCG
04-27-2012, 05:21 PM
I have spent the last few nights studying Crank Case Ventilation... So far .. this has been the best information that I have found...
http://www.shophemi.com/images/media..._ccv_bible.pdf
Chad-1stGen
04-28-2012, 06:51 AM
I have spent the last few nights studying Crank Case Ventilation... So far .. this has been the best information that I have found...
http://www.shophemi.com/images/media..._ccv_bible.pdf
I couldn't get Chris's link to work. But found it on that site doing a google search.
Others having the same issue might try this link instead: http://www.shophemi.com/images/media/p-2273-arrington_ccv_bible.pdf
Slick68
07-09-2012, 02:34 PM
I'm bringing this thread back from the dead. I'm thinking of running one of these.
http://www.steeda.com/store/mustang-oil-separator.html
GeoffP
07-09-2012, 04:52 PM
Mine looks VERY similar to that.
Steve Chryssos
07-10-2012, 11:14 AM
Factor in RPM, oil pan design and ring seal into the equation, as well. A stock oil pan will have difficultly keeping its sump full, so more oil can sit at the top of the engine. The same can be said for high rpm and high g-loads. And of course, an engine with blow-by will puke oil as cylinder pressure actually pressurizes the crankcase.
I have eliminated my PCV altogether as a contaminated intake charge can cause detonation at high rpm. My system uses air oil separators at the valve covers that lead to an air/oil separator tank. I'm experimenting with various bits.
GeoffP
07-10-2012, 05:55 PM
Pictures Steve?
Pictures Steve?
I know HuH! I love pictures.............
badazz81z28
07-11-2012, 06:12 PM
How about the LS6 PCV system? Same issues as early LS1s?
GeoffP
07-12-2012, 03:40 AM
I think you still need a catch can. As far as I know GM didn't start trying to address the issue until the late 2000's. My friend's 2009 truck had the oiling issue BAD. GM has come out with a revised PCV setup to fix it on late model trucks (I think).
Steve Chryssos
07-12-2012, 05:08 AM
Tons, but sorry, it will be a coupla weeks before they launch as they are part of a Grassroots Motorsports web article. HERE (http://grassrootsmotorsports.com/project-cars/1968-chevrolet-camaro/)
Steve Chryssos
07-12-2012, 05:26 AM
I have spent the last few nights studying Crank Case Ventilation... So far .. this has been the best information that I have found...
http://www.shophemi.com/images/media..._ccv_bible.pdf
That's a great article. Thanks!
Steve Chryssos
07-12-2012, 05:27 AM
I have spent the last few nights studying Crank Case Ventilation... So far .. this has been the best information that I have found...
http://www.shophemi.com/images/media..._ccv_bible.pdf
That's a great article. Thanks!
Blue Oval Man
12-26-2012, 12:42 PM
I have spent the last few nights studying Crank Case Ventilation... So far .. this has been the best information that I have found...
http://www.shophemi.com/images/media..._ccv_bible.pdf
As others have said, thanks for that article, it has really helped me figuring out what to do with my engine.
David.
BBPanel
12-27-2012, 10:11 AM
A couple of questions:
Shouldn't the fresh air make-up come from downstream of the MAF and before TB (if it is upstream of MAF isn't there a chance you will run lean?). That may be the implication in some of the drawings but not obvious.
My understanding is the early LS6 valley covers did not have the orifice built in and a PCV was necessary - how does one tell which cover you have? Can you take a small wire and see if it will pass through the vent line or not (for those of us with installed engines)?
And for the system to be effective it must be closed correct? Having an open breather on a valve cover defeats it.
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