Oil control and monitoring vitals on LS series engines

[JMortensen]

Thinking maybe plugging the factory vents and putting the AN-10 vents right in the middle of the valve cover or maybe even 2/3rds back on the high side might help. Wonder how much of the oil is sloshing under accel and braking.

[NewZed]

Some thought on PCV's - sometimes fresh air flows in to the valve covers to purge gases from the block vent, sometimes excess combustion gases are flowing out of the valve cover when the block vent is overwhelmed.  At least on the L6 system, according to their diagram.  GM might have changed things around on the LS.  

 

So if you have a drain back or oil mist carrying problem from the heads because of too much blowby at high RPM, it may be that the block vent needs to be enlarged, not the drain back ports, or the valve cover vents.  The combustion gases start their travels from the piston skirt area, which is in the crankcase.  Even if you run open breathers from the valve covers, all of those gases are hindering drain back or picking up valve train mist/droplets on their way up and out.  You're actually just allowing more gases up into the valve covers.  Seems like you'd want to find a quiet spot in the crankcase and put your extra vents their, leaving the valve area alone.  Less convenient and more work, but it might be a better solution.

 

Just a perspective from a guy with a stock EFI L6.  The GM LSX system might be totally different.

[RebekahsZ]

heavy85 (I appreciate your opinion)-so you are draining from your puke cans (which have vacuum on them from the throttle body), not from your intake manifold-am I getting that right?  I'm not sure what you mean by pushing it...I'm hauling ass best I can.  I don't know how I measure up on Gs, rpms and what not, but I yanked both my tires off the ground 3 times at the dragstrip on Saturday.  You'd have to ask CobraMatt how I'm doing on lateral Gs, I really don't have a good reference due to inexperience.  I wonder effect the location of the vacuum port on the intake stream has...the LS1 port is on the throttle body, whereas my GTO intake system has it on the plastic snorkel tubing further upstream of the throttle body.  You've got your puke cans on vacuum; I think SunnyZ has them to atmosphere...

[alainburon]

All, there are tons of threads on LS1 Tech as well as Corvette and Camaro forums about the PCV LS engine subject. Also there have been multiple write ups about it as well. I see no point in redesigning the wheel when other professionals have already addressed this issue and came up with solutions to the problem. Granted some threads are full of useless nonsense or retarted opinions some do have good information.

 

For what it is worth, all the research I have done and after speaking with Professional Race and Street engine builders they all say the same thing which is to install a good catch can on an LS motor and move on. They main thing about a catch can it’s how it is constructed  and how it is connected. There are some companies out there making good ones as well as other companies making junk, basically a can with an inlet and an outlet which is worthless.  Like the old saying goes “you get what you pay for”. The next thing is to have the catch can connected properly as some obviously do not know what they are doing and connecting the catch can improperly can make it useless. All applications are different and you should connect you catch can according to the set up you are running as a Turbo car will be different than a N/A car when it comes to the PCV set up.

 

There are a lot of opinions flying around as to what works better but when in doubt I would consult the professionals, not weekend racers. I would not take any advice on hooking up anything to my motor from guys that have blown theirs. It’s like taking financial advice from the homeless.  

[RebekahsZ]

You are right, but ls1tech guys aren't any smarter than we are. Professional is a worthless word. I dropped my truck off to a professional with a great racing pedigree in July for an LS swap and after $13,000 and 3 sets of main bearings, I'm still driving the Z that I built myself while the truck gets un-F'd. .

[alainburon]

I never said LS1tech guys are smarter than we are, smart and experience are 2 different things. Some of them do have more experience dealing with LS motors than we do. I was just mentioning that this subject has been beat to death and there are already solutions out there so why start from scratch when the answer already exists. I’m sure the solution did not come from LS1tech only the discussion came from there.

 

As for the Professional term I would have to respectfully disagree. There are plenty of Professionals out there however there are also plenty of guys that claim to be Professionals because they have been working on cars for so long and are far from it. Like they say is not just practice that makes perfect it’s good practice that makes perfect.

 

 

Sucks about your truck man, I would be pissed as I’m sure you are. Hope you get it back soon.

[260DET]

What specifically are these solutions alainburon, that would be a start. Because the conclusion I came to after doing hours of research was that there were products out there as usual but no proven solution other than to go dry sump.

 

I like others in this topic are not writing stuff for fun, saying that there are solutions without specifying them is pointless.

[alainburon]

Too bad you feel my comments are pointless, opinions vary I guess. I was just trying to point out the obvious as some of these threads tend to go into the weeds.

 

As for the solutions there are 2 subjects in this thread. One regarding oiling issues under hard acceleration and the other regarding PCV systems. Both solutions have been mentioned here but have been questioned.

 

These are both proven solutions.

PCV systems issue is very simple, properly install a good catch can or 2 depending your set up get on with it. You may not remove all mist but you will remove most of it.

The oiling issues under hard acceleration is simple as well. Use an Accusump system or go dry sump.

 

One thing that should be very clear to all thinking about addressing these issues is the purpose of your car and a lot of people forget that. If you have a street car with mild mods on your motor and hardly ever go to the track then there is no point in spending your hard earned money on this as there are many LS motors out there with over 100,000 miles and do not use any of these items. I would do a catch can anyways but that’s just my preference. If you go to the track regularly, have a high hp motor and/or are running hard then it may be a good idea to look into this as it will save you money and headaches in the long run.

 

[JMortensen]

One thing that comes to mind reading Alain's post is the quality of Cameron's catch cans. They look homemade, and the oil separation method he described sounds suspect at best, to me. Using a higher quality catch can might offer an improvement. Doesn't mean that he won't still suck a cup of oil into the can(s) but maybe could keep the oil burning plumes to a minimum.

[RebekahsZ]

Lets all be a little more courteous and thick skinned, please-we are all friends here.

 

I've learned a lot from this thread, so lets keep it going. For example, I hope to add two oiling mods this winter. 1) an Improved Racing baffle set. 2) a low oil pressure warning light. I also plan to add a puke can to the engine oil venting system. But what I don't understand is this: why should I put a vacuum source on the puke can (vs) simply venting it to atmisphere? I'm in no hurry to modify the PCV system because I can tolerate an occasional puff of smoke, if that's the only negative to the stock system(?)

Edited November 13, 2014 by RebekahsZ

[heavy85]

Jon - so by that logic your homemade cage is questionable quality

 

 

Just kidding. Yes I made them for several reasons. From prior research many years ago now the 'better' ones had steel wool stuffed in them. I was not comfortable with the potential of small steel pieces being sucked into my engine. Its all about condensing the oil mist so you need cooling and surface for it to stick to and seperare out lf the air. This is why I build a diffuser tube to force the vapor through relatively thick, small holes to help condense out the vapor. They obviously work but also obviously not 100% effective. Im sure there are improvements that could be made like being much taller and I may play with moding them in the future.

 

Now the question about vented or not, I'm not an engine expert but figured sucking out the combustion gases via the PCV system put was better than whatever oil mist got in the intake. Dont know if thats really true or not but the best decision I could make at the time with what info I could find. LS1Tech is not possible at least for

me to wade out any true tech from. Edit: the oil I drain from the cans is black any nasty looking while the oil on the dipstick still looks new for what its worth.

 

Alain - as said before, what you are saying is great for 99+% of everyone but then there are those of us outliers who still have issues.

Edited November 14, 2014 by heavy85

[heavy85]

Oh and I still would love to know where all this vapor is coming from to fix the root cause instead of just treating the symptom with catch cans and such but thats not my focus so will probably never really know for sure.

[260DET]

Oil vapour would primarily be the result of windage is my un/educated guess.

 

But let's stop for a moment and consider the LS engine. What we have is a relatively compact crankcase supporting say six litres displacement, that's eight large cylinders pumping away with the inevitable blowby all of which is contained by the crankcase until it can be vented somewhere. On the stock LS that pressure is vented up the available passages into the heads, at the same time oil in the heads under the influence of gravity is draining down through whatever of those passages which are available and so going in the opposite direction to crankcase pressure movement. Which inevitably hinders both. The solution to which is.............

 

Unless someone has a relevant comment on the above I'm calling it a day, cheers.

[RebekahsZ]

All engines have blow-by (its not specifically an LS issue). I just gotta figure out why we gotta suck it out with vacuum rather than just letting it vent. Is it to try to reduce the resistance of the windage cloud? Do we really NEED to do that? If heavy85 vented rather than sucking, would he quit getting so much oil loss into his catch cans? Feel like trying that? This discussion really still is about oiling.

Edited November 15, 2014 by RebekahsZ

[tube80z]

I'm sorta late to your party and there's a lot of anecdotal evidence for LS oil issues.  I've been told by a number of people that this isn't an issue at all and I'm more or less overthinking it.  I have been a part of a few tracked LS engines and seen them die.  From what I can tell the LS engines have a shit oiling system compared to what Datsun originally gave the Z.  The first problem is the block is not set up to oil the main bearings first.  This is done for a production engine so you don't have any rattles that drive warranty claims at cold startup.  If you look at the aftermarket blocks the oiling is setup with what's called mains priority.  I think there may be a few simple tricks to fix this but I haven't tried them so I won't add to speculation.  I was thinking you might be able to plug the upper galley and then feed it via an external source you could restrict.  For the more adventurous have at it.

 

One the oil gets to the heads it's more or less dumped back onto the cam and the crank.  If you haven't drilled holes in the lifter trays those will fill with oil too.  I can only imagine how frothed up the oil will be from being dumped on all the rotating parts.  I saw an interesting trick I wanted to copy on my engine where a baffle above the cam that directs the oil onto the cylinder block walls.  This was in one of the Engine Masters magazines and was claimed to help with HP.  It seemed like this would help to keep the oil from getting air into it in the first place.  I took a good look at the ideas from Ishihara and Johnson (http://www.crank-scrapers.com/Chevrolet_LS.html) and bought there teflon scraper.  For a little more than the IR piece you can get there laser cut scraper that is a lot better design in my opinion.  And if you're handy (who here isn't?) you can copy the windage tray.  From reading a lot of various articles it sounds like the oil gets wrapped up around the crank as windage and what doesn't goes up to the heads.  And if you run them hard and long enough the quality and volume of lubrication gets to the point where these engines let go.  I have a mockup block from one of these episodes that has a very large hole in the side.

 

So here's what I do know.  If you log the oil pressure and you go around a left hand corner for more than 2.5 to 3 seconds and you're pulling over 1.25 Gs then you'll probably end up with zero oil pressure.  You can overfill all you want and run an accumulator but it won't do a lot of good giving the oil is headed upstairs first.  I also found that if you run down a long straight and jump on the brakes the pressure can drop a lot.  I got to help out at a circle track event and my friends LS powered car would completely fill the right side head until it came out the top.  From reading and talking to a few other people I've been told that this is partly a oil drain back issue and partly related to too much oil going to the heads.  

 

Jon and Richard already mentioned external head drains.  Ideally these need to be a number 8 fitting and hose (1/2 inch).  The heads are drilled and tapped in the back in the valve spring pocket area.  I've uploaded a picture of this done on a SBC to give provide a better idea.  We tried unhooking the PCV hose on the circle track car and hooking it to the dipstick tube.  This worked much better than you'd think.  Up until that point the PCV system (one of the can systems) keep filling and we'd lose over a quart in a couple of laps.  I think if you run a scraper and windage tray, drill the lifter holders, and have external cylinder head drains and do the overfill trick you can probably deal with corner under 1.25 Gs.   

 

Once past the 1.25 G cornering level I think you need to look at a real dry sump.  If you can do some ebay shopping you can put together a good system with a new pump for under 2K and probably closer to 1500.  I did mine using a used pump for around 1250.  That wasn't too much more than an accusump, windage tray/scraper, special pan, and PCV system.  The trick to making the dry sump cheap on the LS is the drive system and mounts.  You don't have to spend the money for the ATI damper unless you want to.  And a used tank and lines can save you a ton of money.  You do need to be able to clean all this stuff and fab mounts, which isn't any more difficult than putting in a motor.

 

Hope this helps,

Cary

[rsicard]

NASCAR guys have a LOT of experience and they keep plenty of oil covering the valve springs to keep them cool and lasting till the end of the race.  Their number ONE problem is valve spring life.  I went to a Dart SHP block because it has priority oiling system.  Also found a racing oil pan that holds 8 quarts of oil, has six trap doors, two kickouts, decel baffle and a crank oil scraper.  Will look into restrictors for the two lifter oil galleries to limit oil to upper end.  Would be nice to have plenty of oil in the valve covers with a slow supply and slower leakdown to keep the oil up there to cool the valve springs.  Also have a pressurized oil reservoir and a way of logging oil pressure to make certain there is adequate oil pressure in the Hi-G turns.  The lesser the amount of Gs in turns, the quicker you get through the turns.

[RebekahsZ]

I really appreciate all the input, but those of you who know me know that this discussion is getting a bit over my head and is exceeding my level if commitment and the time I'm willing to devote to my Z. I don't know if this should be a different thread, or if I need to just do some googling on this related, and oft referred to subject: data logging. Where should I look to learn how data logging works and the systems that are available? How complicated and expensive is it to buy and install a data logging system? What data can be collected? I know there are systems that can allow a driver to collect data that can be re-examined to help you find errors in braking, turning and acceleration. I guess there is also mechanical performance data logging? Are there all-in-one systems that do it all, and how complicated are they to install? I hope you guys know that I've asked all my questions BEFORE having any problems myself. I'm still on engine number 1 in my Z and its running like a top! For some crazy reason, my truck has had 3 sets of bearings in 1000 miles, all bearings were wrecked either on the dyno or at steady cruise on the highway. Just got it back and for the moment it is fine with 60psi at idle cold, 45 psi at idle hot and 60 psi cruising down the highway. Most recent rebuild got align-bored (don't know if misalignment was found or if just for good measure), magna fluxed and re-cleaned, crank turned (I presume checked for straightness), reassembled with a new pump that was disassembled, de-burred and got 3 washers (thickness) put under the pressure relief spring (all according to the guy getting my money). So, I haven't actually wrecked an engine via abuse (yet).

Edited December 6, 2014 by RebekahsZ

[Savage42]

 The lesser the amount of Gs in turns, the quicker you get through the turns.

 

Uh, yeah, NO!  Are you saying to go slower in a turn to pull less Gs and that is faster?  Not going fast on any road course in a variety of cars I've driven.  Why are the cars pulling the fastest lap time pulling more Gs in the corners?  I'm all about slow in, fast out, but when you are doing over 100 mph going into Turn 1 at Sebring (a long, sweeping left hander), you can't really drive that way.  I assume you are talking more about autocrossing and in a car that has good acceleration, as a low powered "momentum car" is all about how much speed (Gs) you can carry through corners. 

 

Cary, your comment about a 2-3 second high G left hander is exactly what Turn 1 at Sebring is, so I better work on getting the scraper & windage tray in the LS6 before my first track day here in the Z!  Don't want to blow the motor, which MANY Corvettes (stock) do on a fairly regular basis here.  Good stuff to know. 

[rsicard]

Uh, yeah, NO!  Are you saying to go slower in a turn to pull less Gs and that is faster?  Not going fast on any road course in a variety of cars I've driven.  Why are the cars pulling the fastest lap time pulling more Gs in the corners?  I'm all about slow in, fast out, but when you are doing over 100 mph going into Turn 1 at Sebring (a long, sweeping left hander), you can't really drive that way.  I assume you are talking more about autocrossing and in a car that has good acceleration, as a low powered "momentum car" is all about how much speed (Gs) you can carry through corners. 

 

Cary, your comment about a 2-3 second high G left hander is exactly what Turn 1 at Sebring is, so I better work on getting the scraper & windage tray in the LS6 before my first track day here in the Z!  Don't want to blow the motor, which MANY Corvettes (stock) do on a fairly regular basis here.  Good stuff to know. 

Should have made it clearer.  The largest radius used in a turn yields the lowest "G" for that turn.  Speed can be kept at a maximum in the largest radius through a particular turn.  Hope this clarifies it.

[rsicard]

I really appreciate all the input, but those of you who know me know that this discussion is getting a bit over my head and is exceeding my level if commitment and the time I'm willing to devote to my Z. I don't know if this should be a different thread, or if I need to just do some googling on this related, and oft referred to subject: data logging. Where should I look to learn how data logging works and the systems that are available? How complicated and expensive is it to buy and install a data logging system? What data can be collected? I know there are systems that can allow a driver to collect data that can be re-examined to help you find errors in braking, turning and acceleration. I guess there is also mechanical performance data logging? Are there all-in-one systems that do it all, and how complicated are they to install? I hope you guys know that I've asked all my questions BEFORE having any problems myself. I'm still on engine number 1 in my Z and its running like a top! For some crazy reason, my truck has had 3 sets of bearings in 1000 miles, all bearings were wrecked either on the dyno or at steady cruise on the highway. Just got it back and for the moment it is fine with 60psi at idle cold, 45 psi at idle hot and 60 psi cruising down the highway. Most recent rebuild got align-bored (don't know if misalignment was found or if just for good measure), magna fluxed and re-cleaned, crank turned (I presume checked for straightness), reassembled with a new pump that was disassembled, de-burred and got 3 washers (thickness) put under the pressure relief spring (all according to the guy getting my money). So, I haven't actually wrecked an engine via abuse (yet).

Not to worry.  AEM electronics and Innovate Motorsports both make data logging systems that incorporate lateral and longitudinal "G" sensors and analog to digital sensor converter/recorders.  Personally, the AEM electronics appears to be the better of the two systems.  It will record the data for playback on your computer.  The next better step up is to have video and data recorded at the same time so that you get a visual picture along with the data and there are systems for that also.  Just more money.

 

As for your truck, something is wrong about how the mechanic is putting the engine together.  With very close attention to bearing quality and clearances (writing them down), there should be little if no problem.  Close attention also needs to be paid to oiling galleys and oil pumps.  After replacing engine bearings, the oil pump needs to be primed and the engine rotated while priming the oil pump such that it has proper lubrication upon first startup. Usually, a new Melling Oil Pump is installed as it is cheaper and of better quality.   Cannot over-emphasize close attention to details.  All crank and bearing saddles must be in alignment.  Stunned to know that engine shops do not have straight alignment bars to put in place of the crankshaft to test for main bearing resistance to rotation versus torque to turn the tool.  Crankshafts should undergo measurement with an computer automated Coordinate Measuring Machine (CMM) to make certain the main and rod journals are in their proper place.  Biggest aspect is TEST don't GUESS.