LS Oil Drain Down

[260DET]

Given the wet sump engine lubrication problems that seem to be common even with a full house baffled, trapdoored, scraped and so forth sump, I'm wondering why. Is a V8 thing, two cylinder heads and not at 90 degrees to the desired drain down route? RB engines need an added gravity or pumped head oil drain setup to race with a wet sump, the original L engine seemed to race OK with nothing more than a full house wet sump.

 

What I'm thinking is the LS problem is partly to do with blowby pressure from the sump area tending to counter gravity in the control of oil movement from the heads as it heads towards the valve cover vents. So, back to the past, one big vent coming out of the side of the sump connected to a  catch can and block off the valve cover vents. Who has tried this, does it help?

Edited April 25, 2014 by 260DET

[260DET]

Oil accumulating in the valley seems to be another push rod V8 thing, neither this nor venting seem to have gained a lot of attention. At LSX forum level anyway.

[260DET]

Am going ahead with the crankcase vent idea, now have a truck sourced filtered cap and a separate precipitator which is basically a large all metal fuel demountable filter I got off Ebay. The GM Performance sump has arrived, it will be modded to accept the vent outlet of course and it's oil capacity improved by adding a 'bulge' on the left side. I guess that this sump was designed to fit in somewhere but it's bowl is poorly designed as to capacity and shape so that has to be fixed. It comes with a windage tray which is good but no scraper. Improved Racing offer one, will check that out.

 

As is obvious this is not going to be a dry sump job and for that reason the alternative has to be designed and done as effectively as possible. LSx's are great for the range of 'off the shelf'  bits and pieces available. Which often make sense as a complete fix. But not always.

[260DET]

Must comment on the terrible GM oil pickup supplied, the bends look like they have been done with a hammer and would no doubt impede oil flow. Quite happy to complain direct to GM but how to do that?

[RebekahsZ]

You won't complain when you exit a corner at 3000rpm and have torque for the first time in your life. I think the diameter is large enough for it not to matter. It's like worrying with mandrel bends in a 4" tailpipe. I think they just spend the money elsewhere, like political bribes, union dues, shipping parts in from Mexico and China, environmental consultants and retiree pensions. With all that overhead, you gotta cut corners somewhere.

[SUNNY Z]

Step 1) Buy a $500 engine 

Step 2) Make 300+ WHP / WTQ STOCK

Step 3) Don't over-think it!

 

If its that concerning to you, do an aftermarket pan, and accu-sump setup. Those bad boys hold like 12qt's.

[tube80z]

I researched this heavily and found for the LS engines they have poor oil drain back from the heads.  So they have a tendency to fill up and when they do drain they fall back on the crank and cam, which ends up aerating the oil.  One solution to this that's been used in old school engines over the years is external head drains.  I found an informative article that even a dry sumped F5000 engine needed these for a specific track.  These need to be 8 AN  (1/2 inch) from what I've found and connect back to the pain using a shield so they don't end up getting backed up.  You can also swap in pushrods with a smaller oil holes to help reduce the amount of upper end oil.  I've seen various methods of venting the engine but it seems one option that looks to work well is via the valley cover rather than in the valve covers.  To help deal with oil aeration and migration you can use a crank scraper.  So all that is on top of the gated pan.

 

Hope this helps,

Cary

[260DET]

Yes, that seems to be the situation with these engines Cary, at the moment I'm thinking that a Holley oil pan with a stock windage tray and Improved Racing scraper and baffle kit may be a better option than modding the GM muscle car pan I already have. Hopefully the oil pickup tube that comes with that pan has smoother bends. Incidentally the tube diameter is about the same as a three liter Nissan VG engine's pickup. 

[260DET]

Decided to stick with the GM Performance sump which will be modified to incorporate kick outs both sides. As for the oil drain down, it is all worked out and will incorporate a large cylindrical fuel filter canister that will take -10 AN fittings both ends and, instead of a filter element, will contain stainless steel scrubbing pads to help prevent too much oil ending up in the catch can.

 

That's all that will be done until the cam is changed when there will be the opportunity to look at the valley area to see what can be done there. Am determined that any potential oiling problem will be taken care of while still retaining a wet sump. Engine may end up looking like an octopus what with all the external oil drain and vent lines

[heavy85]

I like things simple so not sure I understand the need for the octopus complexity. Yes these engines consume oil via the PCV system but put dual catch cans in the stock system and it works. Keep the oil topped up and drain the catch cans as needed but its not that hard to make it work.

 

PS - I made the catch cans out of 2.5" exhaust tubing and plumbing fittings from the farm store. Cheap, simple, and addresses the symptom of the LS oil aeration.

[RebekahsZ]

I'm not sure what I'm missing. I just turn the key, put it in gear and haul ass. When it needs oil, I add some. Am I destroying my engine and somehow don't know it?

[mattd428]

An engine that last over 150k miles doesn't have an oiling problem.

[Domzs]

It's a good idea to mod oil pan to have " kick outs " to gain more volume , just make sure it doesn't look like the C5 pan , " bat wings " . These pans are bad for road course racing . At high Gs turns , oil goes to the side .

 

C5 " bat wings " pan .

[JMortensen]

I'm not sure what I'm missing. I just turn the key, put it in gear and haul ass. When it needs oil, I add some. Am I destroying my engine and somehow don't know it?

It's a road racing on sticky tires problem.

[heavy85]

What Jon said. It sucks soo much oil into the intake that it gets coated with oil. When it cools and next time you fire it up the oil get sucked into the cylinders causing a huge plume of oil smoke out the exhaust for a couple seconds. Freaks you out the first time it happens. The second catch can fixed this but you drain maybe a cup (?) of oil out of them during a track day. The catch cans are in each PCV line from and to the throttle body to help condense the oil mist and minimize the amount getting to the intake.

[Domzs]

Drilling holes in lifter trays will help drain back also .

[RebekahsZ]

I wasn't trying to sound like an ass (it just comes naturally). My LS2 only has a PCV port on the passenger side valve cover...I have that plumbed to the intake airstream in the stock GTO location before the air gets to the IAT sensor and the throttle body. In my rear-facing camera at AMP, I did notice an occasional puff of blue smoke. I thought to myself: "bad valve guides already?"

[260DET]

On mine the valve cover vent hoses will go into the catch can along with the new DIY crankcase vent hose. Don't want to be adding oil fumes to the combustion chamber fuel air mix. Catch can is pretty big and will get drained occasionally, with the VG engine only rubbish liquid ended up there anyway.

[260DET]

Link to the build, well I tried. This grate sight needs a proper host that does common practice stuff